Electric Bike Troubleshooting—Part #2

A typical ECU (electronic control unit) for an E-bike. Most have even more wires and connectors.

As I continue on with this guide to finding the problem with your E-bike, let me say that it is important that you read Part #1 that I published last week.   The notes about safety, knowing if you should do this on your own, and the sequence of tests are all part of this post.

So, you have tested or replaced your battery and the lights on your panel are still not on.   The next step is to check that you are getting that power to the ECU (electronic control unit).   It is normally located in the frame or rack and is not that hard to gain access to.   Note how it and the wires are tucked in to the compartment before and as you pull it out of its hiding place.   Use the voltmeter to confirm the correct voltage is being delivered to it.

There is a possibility of a broken wire or a bad connection between the battery and ECU.   Look for signs of overheated wires at the connectors, that is a sure sign of trouble.   There is also a chance that the handlebar mounted display is faulty, but I rarely find this to be the case.

At this point you can use the meter to check the brake safety cut-out switches for correct operation.   Also, you can check the throttle control for the correct signal it should send to the ECU.   These tests won’t help if the display lights aren’t on, but if they are, here is where you can do it.   A wiring diagram can be quite helpful at this stage of the testing.   Make sure to power off the bike and disconnect the wires at the ECU during these tests.

The brake switches will be a simple continuity test, while the throttle test is different.   Most (but not all) throttles are basically a dual 5K variable potentiometer that works a lot like an old fashioned volume control on a radio.   The ohm reading should read (and change) in the 0- 5K  range when the throttle is twisted or pushed.   If you do decide to change the throttle unit, make sure to get an exact replacement from your bike’s manufacture.   If none of these tests show a bad component, then you can assume the ECU is bad.   Once again, an exact replacement unit is the best.

Let’s say the lights on your control panel are working, but you still can’t get the motor to run (and you have tested the brake switches and throttle unit)..   Chances are you have a bad ECU or motor.   There are a few other things that it could be, but on most bikes you will find one of these two items are the culprit.   On a true pedelec bike (no throttle), or an intelligent pedelec bike (with a load sensor hooked to the pedals or rear drop-out), the testing could be beyond the scope of this article.

On those bikes, I strongly suggest you have a factory trained tech do your troubleshooting and repair.   At minimum, talk to one on the phone to guide you.   True pedelecs use a hall sensor on the bottom bracket to trigger the motor.   These are not too complicated.   An intelligent pedelec uses a computer and sensitive load sensor that can be quite complicated.   The load sensor can go out of  adjustment and I have dealt with this, but once again, complicated.

Here are a few tips on deciding if your motor or ECU is the bad guy.   If you can hear the motor run, but it won’t turn the wheel, then the internal reduction gears are stripped or broken.   This you can fix.   If the motor jerks, but won’t run, then it is the ECU.   If the motor won’t run at all, then it could be either the motor or ECU that is at fault.   I would suspect the motor in this scenario, but it could be either.

This is a brushless hub motor on a Hebb E-bike. Not all hub motors have internal reduction gears like this one. The larger style hub motors are normally direct-drive.

Motors come in two varieties.   Brushless motors are the most common on modern E-bikes.   They actually run on AC (alternating current) that is generated by the ECU from the DC (direct current) that the battery supplies.   Plus, they are not run just by the voltage level, but by sine wave variations.   Yes, complicated, but you don’t need to understand and design it, just find the bad component and replace it.   Also they come in sensored and uncensored versions.   Again, replacing the bad part is your only concern here.

A brushed motor is simple.   You can feed the power from the battery directly and it should run.   They have only two wires, where a brushless motor can have up to seven.   Brushed motors have brushes that can wear out.   They are pushed to a turning commentator with a spring.   If the brushes wear too short, or the spring gets overheated, then the motor won’t run.   If that happens, it will cause heavy wear or damaged that can’t be fixed.   Also, the windings in the armature can fail.   These motors are normally not too expensive to replace.

One other tip for brushless motor problems that I have been given by the technicians has never worked for me, but you might have better luck with it.   Disconnect the wires at the motor for a few minutes.   Reconnect them and try it again.  Electrically  separating the motor and ECU in this manner can set a reset into effect that has been known to solve the problem.   Not for me yet, but maybe for you.

Some ECUs have built-in memories that store trouble codes.   They will read out with light flashes that correspond to a particular problem.   Once again, these have never helped me, and the erroneous codes they spelled out were useless.   In each of those cases the ECU replacement is what brought the bike back to life.   But they are there to help you and could tell you where to find the problem.

One problem you might run into, is that each E-bike electrical system is different.   There is no set standard for them.   One manufacture can use different systems on different bikes, and even in the same model run.   I know that this fact can be discouraging, but the makers of E-bikes are coming up with better and more reliable electronics everyday, so problems are disappearing fast.   The bikes just keep getting better and better all the time.   That is encouraging.

I hope this has been able to help you.   Remember that sight and feel can be your best tools.   My visual examinations have found more problems than you could imagine.   Many of the things that can go wrong are simple.   And by all means, don’t get in over your head.   Don’t make things worse by doing checks you don’t understand.   And do it all as safely as possible.

Questions?   Plus, I will revisit this subject as more info trickles in.

Keep that E-bike running well, Turbo.

“Bikes are a right livelihood.”—Scot Nicol.

About Turbo Bob's Bicycle Blog

E-bike Enthusiast Vintage Bike Enthusiast
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373 Responses to Electric Bike Troubleshooting—Part #2

  1. chris says:

    I have a synergy 200w folding 20 inch wheel bike , the phylion batteries are a bit on the flat side and i am going to dismantle and try to swap the bad cells for good and make one good battery. in the meantime I am planning to buy 2 ,12v deep cycle lead wheelchair type batteries to keep me on the road ,connecting them to make 24 volts, problem is , I can only find 12ah ,and the bike is made for 10ah, research has shown me that doubling the batteries will double the volts but the amp hour will stay the same? is that correct and if so would 12ah do any harm? apart from taking the watts up a bit?

    • Chris, the minor difference in amp/hour ratings will do two things. Increase the range slightly over the lesser batteries, and increase the charge time a little bit.
      Here in San Diego, your selection of SLA (lead) batteries is large and any battery can be found. But, I have given up on SLA batteries for many reasons.
      Hope your project comes together the way you like, Turbo.

  2. Alex says:

    After climbing a hill my E-bike stopped working. The light and battery indicator LEDs are working but has no power to the wheel. Does a bad ECU still give power to the LEDs but won’t give power to the wheel?
    If not I suppose it would be the motor that failed.
    Thank you.

    • Alex, I need a little more info on your E-bike to give you a clue what to check. I would suspect the ECU from your description. Make sure you check your brake safety cut-off switches. Also, there could be a bad connection that lets enough power through while the bike is on, but fails when the motor load is applied. Do the lights dim when you attempt to add power. Does the throttle feel normal mechanically? Did you smell a hot plastic kind of odor from any of the componenets?
      If it is a brushless motor than it can be a little harder to diagnose. A brushed motor bike is much easier to decide which to repalce. The ECU is generally less expensive than a motor, so changing it first would be a good way to go. If the company that made it can’t help you, then contact Pat at San Diego Electric Bike. He has a ‘generic’ controller that will run most E-bikes at a decent price. You can Google him for a phone #.
      What brand, motor type, battery voltage and battery type is the E-bike we are talking about?
      Good luck, message me back for more help if the E-bike company or Pat can’t solve your problem. And let us know what fixed it and how the process went.

  3. Alex says:

    Thanks you for your help.
    Actually the bike is similar to this one http://www.ebay.co.uk/itm/ELECTRIC-MOUNTAIN-BIKE-FOLDING-/190704258809?pt=UK_Bikes_GL&hash=item2c66dc0ef9
    I’ve had it about a month.
    It just stopped working when climbing a hill. I dont remember of any odor coming out. The bike has no throttle and I don’t think it has a brake cut off. The light works so the LEDs on the handlebar work normally. Adding power does nothing to the wheel, no electric motor noise at all. Also the connections seem good.
    Now I live in another country so it’s difficult to send the bike back. I am hoping to fix it myself, and no one knows here seems to how to fix it. I’ll check Pat too thank you!

    • Alex, the bike you have shown me is the same as my Richen Warrior 26. It has a thumb throttle and a pair of brake cut-off switches. It is a brushless motor bike with a hall sensor on the bottom bracket to turn on the power when the pedals are moving. That sensor could have come loose, or the wheel with the magnets that turns with the pedals could have been pushed back too far. Look at that wheel and make sure it turns very close (almost touching) to the sensor there. On my Warrior that sensor was loose when I got it. That wasn’t why it didn’t run, but it still needed tightening and a adjustment so it was close to the turning wheel on the pedals.
      When I got mine, the ECU was inop. The company that sent it to me was able to send a replacement ECU that fixed it. Pat also has a ‘generic’ ECU that will work, but it will require some minor wiring work.
      Any E-bike you buy should come with a 1 year warrantee. You should try to contact the company that made it or sold it to you for help, parts and a repair.
      Hope this helps, keep trying.

  4. Ziad Al Baff says:

    Hi all of you.
    My motor has a small window that is leaking oil.
    I guess that this oil should lubricate the bearings ??!!
    What type of oil can I use to refill it because I’m starting to hear some bearing sounds.

    Thank you.

    • Ziad, all E-bike motors I have seen use permanently sealed and lubed bearings.
      I will need more info, and maybe a photo to help you out.
      Old time grinder (and other use) motors have a place at each end to add some (a drop or two) of auto motor oil (30 wt).
      If your E-bike motor is getting noisy, it might need replacement.

  5. Ian says:

    Hi, my E-bike is blowing the fuse often and the wheels are getting tight when I’m using the pedals. what do you think is the problem?

    • Hi Ian, first off, a fuse can fail with time, but not very often. If a fuse blows, replace it once and if it blows again, then don’t replace it again until the reason is found and fixed. It is there to protect your E-bike’s system from damage and a potential fire. Of course, only replace it with the correct type and exact amperage rated fuse the bike calls for. I have seen fuse blowing problems with E-bike systems that are not correctly matched (normally on extended hill climbs). I would expect this is a recent problem, and not one you had since the bike was new.
      The reason your fuse is blowing is the bike is drawing too many amps through the fuse. Your mention of the wheels getting tight lends me to believe there is some kind of binding going on. Similar to having the brakes held on during riding, but most likely in a bearing or motor winding failure. It could be a mechanical problem with the bike itself.
      Is this bike a conversion or one from a normal E-bike maker?
      After a complete check for binding, if nothing there comes up, a amp gauge should be used to help isolate the problem. Is there an E-bike shop in your area that can take on the diagnosis? That might be you best bet.
      Remember, you can feed me more info, I might be able to help—and once the problem has been found and fixed, let us know what it was.
      Thanks for the question, Turbo.

  6. Andy says:

    Hi – I have an electric battery that is fully charged (reading 12V output) but the on/off switch, which is illuminated, is very dim as is the intgreted LED light. I’m thinking there might be a loose connection somewhere but I’ve opened up the battery and there’s nothing obviously loose or disconneced.

    One interesting effect was when I plugged in the charger the on/off switch and LED were at full brightness.

    Any ideas? Any help would be appreciated. Thanks.

    • Andy, I will need more info on your bike and battery to answer your question. I do think that the more common set-up is a 24 volt battery pack that has two 12 volt batteries inside. It sounds to me that they are now bad and need replacing.
      If that is the case then you can replace the entire pack (if they are still available from the maker). The less expensive way to go is to buy the two batteries locally or online and install them into the casing yourself. Make sure the size and the amp rating of the replacement batteries are the same.
      Remember that with SLA (sealed lead acid) batteries, you need to recharge them right away after each use to get the full life span out of them.
      So give me some more info or let us know how the fix is going.
      Thanks, Turbo Bob.

      • Andy says:

        Thanks for the quick reply.

        It’s one of these:
        LiFePO4 Battery Pack 36V 10AH Electric Bike Integrated controller box,unique design; High quality LiFePO4 battery pack

        Sorry – I meant that it’s reading 20V (not 12V). It’s a new unit and the battery power light is showing a full charge. I guess that one of the battery connecting cables may be damaged? What do you think? Alternatively, is it more likely that the circuit board is damaged?

        Thanks again,

      • Andy, being a 36 volt lithium battery it should read at least 37 volts when fully charged. Are you sure you are using the correct matching charger?
        Is this a direct replacement for the old one on your bike? Is it an up-grade? Did the charger come with the new battery?
        Was the bike working ok before the battery replacement?
        These questions are my first thoughts to help track down your problem.

      • Andy says:

        Hi Bob – the charger came with the battery. This is an upgrade to an existing battery and the bike worked fine. I’m sure it’s an internal battery issue just because of the low voltage that’s being output (thanks for the 37V tip – wasn’t sure what it should be). The fact that I’m showing 19.xx V would suggest to me that 1/2 the battery isn’t connected correctly or there is a fault on the circuit board – out of the 2 what would be your best guess?

        Thanks again.

      • Either way, you need to contact the supplier and return it for a new one. Also, I would ask them to double check the one they are going to send you to make sure you don’t have to go through this again.
        Tell us when you get it right and how it works.

  7. Rob Rahaley says:

    Hi Bob

    I have a 24V EVS Powerped Sherpa (www.evehicles.com.au). The electric motor has started cutting out intermittently then it comes back on. The local dealer doesn’t have a clue – sold me a new battery that did nothing. Any suggestions? Other than a dud controller, what else could it be? It happens under pedal power and under throttle power.



    • Rob, I would think your E-bike has a motor with brushes in it. They wear with each turn of the motor. If you have run it quite a bit with this going on then there is a good chance the commentator is heavily worn or damaged. It might still be in good enough shape to clean (maybe requiring a lathe turning) it up for good contact. It shouldn’t be too hard to get inside the motor (removing a cover or side plate) to have a look. Electric motor brushes come in many sizes and may be found at a electric motor supply firm locally. There are sites on the web that might help guide you. It will most likely require soldering to replace them (and some tricky moves to hold them in the housing because of the springs that push them onto the commentator) while you reassemble the motor.
      It may require a motor replacement, which could be hard to find.
      Good luck, let us know what you find.
      If it is a brushless motor, then none of the above will help. I would look for a bad connection (by looking for an overheated—-melted one).
      P.S.—a shop that rebuilds automotive starters might be able to help.

      • Rob, some online checking didn’t bring me to the answer either, but makes me think you do have a brushless motor. If you do, then I would normally blame the controller (but not from the way you explain the problem). I might blame a connection or a switch or a fuse for this, but it is hard to say without some hands-on time with your machine.

  8. paul rout says:

    My wife’s electric bike battery indicates full but when its put on the bike there isnt any power. No power on the power indicator lights, there is only a bit of power to the front light realy dim light

    • Hey Paul, some basic voltage checking on the battery is the place to start. If that shows good, look for a poor connection from the battery to the bike’s plug.
      Do you have a local E-bike shop that can help you?
      Let us know how it turns out. If you still want more help here, I will need a little more info on her E-bike and what you’ve found.
      Thanks, Turbo.

  9. J Bennett says:

    Great information on troubleshooting. Turbo Bob , you doing great work here. I have added a posting to my blog that details my ideas for testing battery packs and the charging systems that feed them. You can see it on my blog at http://mybatteryman.com/blog/?p=74

  10. AM says:

    I know it’s March already but I have just bought an e-bike one of the cheapy ones and I am having issues with the motor getting hot. Hot as in more then hot enough to fry an egg on. It comes with a sweet burning but not quite burning smell. I’ve only barely rode it four miles, is this normal for an electrical bike? I really don’t want to end up frying the motor. Tried googling it haven’t gotten to far, wrote the company got even less answers.

    • AM, my ideas here have to do with some type of binding in the motor or the movement of the bike (bearings, brakes and the such).
      There is still much to be desired in the makers and dealers of E-bikes towards service and quality. I get the feeling you bought this bike online and have no dealer support to lean on. That’s a shame, but for many it is the only way to get an E-bike.
      It sounds like the damage is already done. I would try to do a return and refund move. Maybe then you could move forward with a bike from a local shop that comes with the backing that all E-bikes need.
      If you can’t resolve the problem locally, then a return might be your only option.
      Let us know how things work out and if the problem does get solved, what it was.
      Good luck, Turbo.

      • AM, to add to my response I want to say that an E-bike is an electric-assist bike. Most are not really designed to use the motor as the main (and only) power source. You are the other one. It is best to almost always pedal the bike, and let you and the motor share the motive power. This is the most important as you climb hills, especially for the longer ones. The old style brushed motors are the worst for getting hot. Some E-bikes have a thermal shutdown mode that will protect all the systems when the heat rises, but other will not. If it does have this system, the power will resume after the motor and controller cool. If it doesn’t, this means if you are working the motor too hard that it will continue to heat until failure takes out one of the components, and maybe damaging others. Consider this as you decide what the problem is and how to deal with it, Turbo.

  11. CJ says:

    I have a 2011 Eco ped Pulse 48V 500W E -Bike. I installed new batteries.
    I started to ride it and then I smelled burning and the bike cut out. So I opened up the battery case and found the fuse holder was melted and both connectors in the fuse holder were black and the spring inside melted.
    The fuse did not blow though the positive wire is getting very very hot and caused this I assume?
    Why did this happen??
    The bike was fine before.

    • CJ, I would have to see it all for myself, but I think what may have happened is a bad connection at the fuse holder. The fact that the fuse didn’t blow makes me think this. As a wire makes a poor connection and has heavy amperage going through it, it will begin to heat from the resistance (similar to a basic light bulb). The more it heats, the worse the connection gets. And gets hotter as a result.
      I have had this happen on my own bikes. A properly crimped and soldered connection is necessary for these wires that accept a high draw under load. The correct way to test this would be to install a new fuse and holder (the right heavy duty one with the correct sized fuse), and do an amperage draw test (with the correct test equipment or meter) to make sure that was the problem.
      If you can’t do this on your own, an E-bike shop (or even a local auto electric shop) can help.
      Let us know where this takes you and how the fix comes together.
      Thanks, Turbo.

  12. EG says:

    Just bought a used Kona Electric Ute. Everything worked fine for the first few rides. Then, the electric assist started to rattle/shake (could definitely feel it from the front hub) and then stopped working all together. I kept riding, stopped, unclipped the computer/controls and reconnected them. Eventually, it started working again. This has happened on two separate rides…about 30mi. in after a few relatively steep hills.


    • EG, not all E-bikes have a thermal shut-down mode, but many do. It is possible that as things started warming up, (the motor, ECU and/or battery) the bike shut itself down to protect the components from excess heat. One good thing about a well made E-bike is that all the pieces are matched to help prevent this.
      Plus, on almost every E-bike, it is important to pedal fairly hard on the hills to help the electrical system under load. This helps prevent it from working too hard and developing excess heat.
      The fact that the motor system came back to life is what leads me to this explanation. It could be an entirely different problem all-together.
      On many E-bikes as the battery is about to come to the end of its charge, they will make the motor kind of surge on and off at a lower power output. Judging by the fact that you had already completed 30 miles, this might be what is happening. As the battery gets lower on charge, it will have a rougher time outputting the hill climbing amps.
      You may not be experiencing a problem with the bike, but just its built-in limitations.
      Keep an eye on the symptoms and try to decide for yourself what is really taking place. If you need to, seek an experienced E-bike shop to help you.
      Let us know how things work out.
      Thanks for checking in, Turbo.

  13. ADI says:

    I’ve had my 48v 1000w brushless motor bike for almost 2 years. Today as I was riding it up a fairly steep hill the motor stopped working. The thumb throttle light works, the led lights work, but when I press the throttle the motor just jerks. The motor was fairly warm but not too hot and no smoke from anywhere… I’m going to try and disconnect the motor from controller and see if that works.

    • ADI, assuming your motor is a sensorless one (just three wires that hook it up)(sensored ones have about 5 extra smaller wires too), then I would suspect the controller.
      Of course checking all the connections is a good start to the process of finding the problem.
      Normally in this situation I would go to the motor first if it was a sensored one. Most E-bikes use a sensorless motor, so the jerking tells me the controller is sending a bad signal and is most likely the issue here.
      Sorry for the late reply, remember to tell us what you find and ask more questions if needed.
      Good luck, Turbo.

      • Bob Loblaw says:

        I’m having a similar problem with my electric bike that has a 48v 1000w brushless motor. I checked all the wires and connections to see there isnt anything loose or out of place. The led battery indicator on the thumb throttle is lit up, but when I give it any amount of power it just jerks and turns the wheel slowly if suspended off the ground, and only gives little pulls without propelling the bike at all when both wheels are on the ground. What do you think the issue could be?

      • Bob Loblaw, I am not sure if this will get to you, as you commented on a comment and this might not make it to you.
        Bob, the sensors in the motor, the sensor connections or the controller are common reasons to have this problem. Usually it is the controller, but check the connections and hope it isn’t inside the motor (a problem with the sensors or wiring there).
        If the new controller is not a direct fit, hooking up the sensor wires correctly could be tough. The new book—”The Ultimate DIY E-bike Guide” by Micah Toll has a nice section that explains how to do it.
        You can run the motor without the sensor wires on most E-bikes. It can affect low speed torque and make starting off a little jerky, but many E-bikes are run this way.
        Let jus know what fixes it and if you have any more questions.
        Good luck, Turbo.

  14. Brian Wolf says:

    Hello, I have an emotions electric bike. My problem is that the motor will intermittenly stop assisting when riding. Will also get lights flashing and the motor stop asisting when using the blinkers. I have taken the covers off and see no obvious signs of wire damage. Have moved the wires to make sure that the sort was not where the wire go thru the frame. I know this is not much info but do you have any idea what the problem could be? Is it possible the ECU could cause a problem like this?

    • Yes Brian, that is not much to go on. If this is a newer bike, (and by your short description I think it is), then the bike should be on full warrantee. Plus if it is the bike I am thinking of, it has a very advanced torque sensor controlled system that uses electronics that are different than most E-bikes.
      Just take it to the dealer that sold it to you and let them diagnose and fix it under warrantee. If you bought it online than some expensive shipping and a long wait might be in your future. You might get them to cover the shipping. Make sure to insure the package, as shipping can be very damaging to your bike.
      The part about the blinkers (turn signals?) makes me wonder if we are on the same page about which E-bike we are talking about.
      If it is not a torque sensor controlled bike, than I would look for overheated connections in the battery and controller wires making a poor connection.
      Give me more info if needed, but I do hope the dealer who sold you the bike can solve your problem in a flash. Turbo.

  15. kgnot says:

    Hi Turbo Bob.
    I have a very special problem. So my electric bike can have another person, so usually its me and my girl. Anyway, the control box is crystalyte and it gives 25 amp to the motor. The control unit along with the battery and the bms are in a black plastic box for scooters on the back of the bike. I isolated the wires and made many holes on the bottom as I am afraid rain.
    The problem : the crystalytte control box shuts down when overworked or too hot. I just dont know why. I can just guess. Once it shuts down you have to disconnect wires and restart the cirquit. Resetting the control box won’t work. It’s happened many times and today was hot so it just started to shut down. It had this problem first in winter when the control box was outside so I moved it inside because I thought it was the snow….I will check the cables make more holes and maybe change the brand. I changed one control box already and the result is same. Is it the battery? I have friends with such bikes, they drive non stop and I can’t hear them complain about this problem….any ideas? is it a bad connection on a wire touching the bike?

    • kgnot says:

      And I am thinking at night is it possible to be the battery itself. It is very expensive battery from china, 40 Ah and it stays on 4 bolts holding the scooter box in place. The heads are sticking out a little and I have isolation on top of this but still…could it be the vibrations to disconnect some litium cells causing the control box to shut down? But then how can the link go back to working after I reset the circuit?

      • Kgnot, it’s hard to be sure, but it sounds like there is just too much power going through the system, causing heating and shutdown. I think first I would check for binding in the wheel bearings or something that might be rubbing on them. Have you checked this, or for dragging brakes?
        Still, that battery sounds quite large and the amp draw seems excessive. I am thinking this an electric scooter, not an E-bike. It is probably pretty heavy and it sounds like you are riding two people on the bike (more weight).
        Was this bike originally equipped with SLA (sealed lead acid) batteries? It is important for the motor–controller–and battery to all be matched to work correctly. I have seen when upgrading to lithium from SLA that sometimes the draw can be too much for the battery.
        The heat part is what you are fighting, that is probably why you are getting a shut-down. Many systems have a thermal shut-down to protect the components. I suspect this is the problem you are having, being caused by one or a combinations of reasons.
        Good luck figuring it out. Did you buy this bike from a local dealer that can help you?

  16. kgnot says:

    Yes and no. It is kind of a scooter or rather a moped I should say. It was originally with a jaul battery. I also started to suspect the heat and the bms in particular to be guilty for the shutdown so I dont know if I have to put the control unit outside…maybe I will put the bms outside and tape it? So the control box is a crystalyte 25amp stream, for 48v. I carry 2 people, groceries and newspapers. It was a very good bike. But back on track. The battery is 40 amp hours lifepo4 battery so I think I need the bms to connect it to the control box. I cant just cut it, am I wrong? My coleagues have batteries from chez republic, only litium with one wire comming out so they said their bms blew on 4 of them but they can just connect it to the control box. But I have 16 wired going into the bms of mine…can I still put them together. Please tell me advice I need this bike with engine!

  17. kgnot says:

    Sorry about spelling man I type from my mobile phone. I will try to be careful.

    • kgnot, I don’t know what I can do to help. It sounds like you have a lot going on there. Even though electric scooters / mopeds are similar to E-bikes in many ways, I am more geared for the E-bikes. There has to be someone local to you that can help you figure out why you are having problems.

  18. kgnot says:

    Finally I managed to solve the problem. I managed to find a technician at last and we checked all the connections and it turned out that there was a broken link inside the battery itself. So I had to open up the lithium phosphorus lifepo4 battery and repair it. The tech said the heat is likely to cause serious problems if it goes over 68 degrees. The control box works til 80 and the battery til 70. I left my crystalyte control box, took care of my battery and the bms is out of the schematics althought it turns out it is working perfectly. I am very happy today already but my feet need a rest as I was pushing it for a week like a slave in Egypt. I also redid the whole storage place for the battery, removing all the straps I had before and putting foam all around it, making a few more holes and special place for the control box too. I hope the vibrations won’t move anything. What I really want to do is to have the whole scooter box float horizontally on something like a jelly so the vibrations will be non existing. Or put suspensions, but it looks very complicated as the tire is very close to the frame. I appresiate ideas.

    • Kgnot, good deal. I should have mentioned to check the main connections in the wiring, and I am glad you found it. Bad connections do tend to heat from the resistance under load and can cause that problems you had.
      Vibration is part of biking. Most batteries are mounted pretty solidly to the frame and generally don’t cause issues. If you let if float around too much that might be worse than a solid mount.
      Enjoy the ride now that everything is back in action.
      Thanks for the questions and following along with my writings.

  19. Bob Teska says:

    Hello Bob, great blog you have here. Glad I found it.
    My problem is with one of the inexpensive Chinese Scooters.
    Motor started to just JERK while under load.
    Did some testing and Service Tech and I believe it is a controller problem.
    Motor is 700watt 48 volt brushless, with sensors, with lithium ion battery system.
    Looking at a generic controller however it is 800watt.
    Should be here in a few days. Any tips you might have or any place you might
    be able to direct me for tips on installing would be great.
    Thanks for any input you might have.

    • Bob, yes I would suspect the sensors in the motor, the sensor connections or the controller to be causing such a problem.
      If the new controller is not a direct fit, hooking up the sensor wires correctly could be tough. The new book—“The Ultimate DIY E-bike Guide” by Micah Toll has a nice section that explains how to do it.
      You can run the motor without the sensor wires on most E-bikes. It can affect low speed torque and make starting off a little jerky, but many E-bikes are run this way.
      Let jus know what fixes it and if you have any more questions.
      Good luck, Turbo.

  20. Mike says:

    Hi there, I saw you giving out some really helpful answers here as I was looking for some info on the issues I’m having with my bike. Any advice you could offer would be greatly appreciated.

    So I bought a used 2011 ecoped pulse, back in early june. I bought it from a friend who I am quite sure barely used the thing at all. It only had 30k on it when I bought it and not a scratch… still smelled new even. Since then I’ve put just under 1500k on it.

    Anyway. So it worked great for about a month. I use it everyday. to get to work and groceries and such. First thing I noticed was that I started slowly not being able to travel as far as I used to without losing speed. This kind of peaked at a certain point, and I just chalked it up to needing a new battery. Then I noticed the rear tire was warped… it started as a slight rhythmic bouncing as I was driving so I looked at it, and sure enough it was wobbling a bit as the wheel turns. I assume this just makes the engine work harder which can’t be good. I don’t make a ton of money, and I’m in the process of moving right now, so I just kinda crossed my fingers and hoped it would get me through the rest of the summer and I would fix it up in the winter…. today however I went to ride home after work and the throttle was not engaging. It was fully charged, display lit up, signals lights and horn all work fine… just no juice. I was reading this article and now I’m thinking it’s either the motor or the ECU… was wondering what your thoughts are?

    • Mike, yes it could be the motor or the controller. My first thought is a bad connection in the wiring. It does sound like the battery power is getting through, but I would check the wiring to the motor from the controller very closely before going further. Even the main power from the battery could get through with enough juice to run the lights, but fail when the motor is engaged (although I don’t suspect that is the problem) if there were a bad connection there. Look at all the connectors for overheating and feel them to make sure they are tight. Also, one of the switches in the brake levers that cut-off the motor could be stuck or broken. I sometimes see throttle units that fail inside or mechanically. These are easier and cheaper fixes than motors and controllers. Plus if the problem is that simple, replacing those expensive parts still won’t get it going.
      Once you get it running, get that wheel fixed too. It will only get worse, possibly to the point of being a safety hazard.
      Thanks for reading, good luck. Make sure to write back with any more questions or to tell us what it took to get it fixed, Turbo.

      • Mike says:

        Wouldn’t that be nice if it were something as simple as a connection… I got a guy coming today who’s more mechanically savvy than I. Thank you SO MUCH! Really.

      • Mike says:

        Just a quick update. I’m thinking now it may have something to do with the brake switch as you mentioned. When I attempt to move the rear tire with the pedals (while on the kickstand) it’s very difficult and the wheel stops almost immediately after I stop peddling as though the brakes were stuck on. I’m not sure where this switch is though. Looking into it now.

    • Mike, that sounds like more of a binding problem. The binding could come from a couple different places. Like bad or mis-adjusted bearings—a stuck or malfunctioning brake and maybe just an adjustment problem with the brake.
      The motor cut-off safety brake switches are at the brake levers (normally) and have wires that go to the controller. If they are not working correctly then they electrically shut off the motor when they shouldn’t. They are designed to turn off the motor when the brakes are applied when working correctly. When they brakes are not on, then the motor should run when you apply the throttle. They would have nothing to do with heavy binding in the motor or the wheel it turns.
      If it is a binding problem, then try to figure it out so the wheel turns easily and smoothly.
      Keep at it, it should come to life when the exact problem is found and fixed, Turbo.

    • Also Mike, if the rear wheel is really bent or warped and you have rim brakes—then that is most likely the issue. If it uses a drum or roller brake, then the bent rim wouldn’t be causing the binding that is keeping it from turning easily and smoothly.

  21. Melanie says:

    Help! Tried everything and everywhere! I have a cyclamatic gte step through? Was working great. Good range, long battery life. Was on it all day and got home with more than half battery. Hanged pannier rack because I was adding a child seat. I don’t know if my toddler touched something but after I changed the pannier rack (I did not move any other nuts or bolts except for these….) I now have no power. No indicator lights on handlebar panel. No back or front lights. No power at all. Battery now fully charged and its the same…… What could have gone so wrong in changing the pannier rack?

    • Melanie, that’s too bad. I would suspect a connection problem, maybe a loose connection plug. It is possible the fuse in the battery casing blew or failed. On some, the battery won’t charge with a bad fuse, but on others they still will. Does your battery connect automatically when it’s installed or does it have a plug-in connection? It does sound like the power from the battery isn’t getting through to the bike’s electronics, so the wiring and connectors between the two would be the place to look.
      Hope that helps. Let us know what fixes it and ask more questions if you need.
      Good luck, Turbo.

      • Melanie says:

        It has a plug in connection so two fuses. No current coming out bottom of battery. Current going through fuse fine

  22. Melanie says:

    Oh! I now understand! No! It plugs in to charge but connects automatically when slotted into bike

  23. kgnot says:

    I have hard time wrapping my mind around having no current and yet having one througout the fuses

    • policetac says:

      I think they mean that they are getting no current through the system, but upon removal and testing of the fuses individually, the fuses show current is able to pass through them.

  24. Marcus says:

    Hi Bob great blog, I hope you can help as I rely on my ebike to get me to work. I have an ebike kit from a british expat in shanghai mounted on a Raleigh gentlemans touring bike with Zipper fairing mounted up front. I commute 60kms a day on this bike and have clocked up over 5000kms rain, hail, or shine here in Australia. The kit was a 500watt brushless hub motor, 21AH Lithium Ion 36 V battery, controller, brake switches etc and a decent bike computer, cycle analyst?, from a chap in California. With moderate effort pedalling, I’m 55yo, I can do about 40kmh for an hour on this rig. Turning to the matter at hand, out of the blue this morning the motor started intermittently cutting out for just a second at a time. I could still maintain around 35kmh but every 5 or so seconds there was this short period where I could feel the power drop off but then come back on immediately. At the same time it did this the speed display on the bike computer would momentarily jump from 35kmh to really high speeds, 300-400kmh, and then revert to normal as the power came back on. I had a short on the main battery leads to the ECU a while back and with that the ‘cycle analyst’ computer would shut down completely and then reboot. It hasn’t been rebooting with this current problem. I thought it may have been the thumb drive but I was rolling down one of the steep hills on the commute doing around 50kmh with zero throttle and the display was still intermittently doing its weird thing. Does this narrow it down to either faulty brake switch, ECU or short between either battery and ECU or ECU and motor? Kind Regards Marcus

    • Marcus, as I read your letter my first impression is a bad connection between the motor and ECU. Look for a broken or frayed wire on the main three motor wires and the sensor wires. And to pay special attention the connectors in that wiring harness.
      If it is a front motored bike, those wires twist with every turn of the handle bars and they can pull loose from that action. A rear motored bike can also suffer from the wires getting pulled or having something (your feet or maybe even a person who is curious or malicious) get caught on them.
      It could be a component, but a bad connection seems most likely.
      Go over it with a fine tooth comb and you might be able to fix it in a jiffy.
      Let us know, Turbo.

      • Marcus says:

        Hi Bob, just to let you know that I did two things and the problems resolved. Not sure which one though. I disconnected the brake lever cut out switches and then made sure all of the wiring harness connectors were all as firmly joined as possible and then taped them together. Did visually check all the wiring but could not see any bare/worn wires. Bike now back to normal and enjoying my daily 60km commute at 40kmh. Many thanks for your advice, kind regards Marcus

      • Great news Marcus. It is nice to know I could help and your bike is back up and running.
        I wish more would tell us of the results of their problems like you. This column has lots of responses but most don’t tell us of their successes (and failures?).
        Thank you for reading, riding and following along.
        All the best, Turbo.

  25. clive says:

    Hi, I’ve got an electric bike and the back motored wheel doesn’t want to spin. I can hear the motor but it sounds like it’s slipping and the battery meter goes into the red. What might be the problem please?

    • Clive, that isn’t much to go one. Normally if the motor is running and the bike won’t move it would be broken or stripped gears inside the motor housing. That isn’t too hard to fix, but with some motors getting the parts can be a chore.
      If the motor is jumpy and making weird noises but not actually turning them I would suspect a problem with the internal sensors, the sensor wiring or the ECU.
      As far as the battery meter being in the red, that would normally tell you the battery is bad, not taking a charge, or about some bad connections between it and the bike. Another possibility is a bad charger.
      The motor not really running could be a total result of not enough power from the battery.
      The simplest fix might be a new battery.
      If there is just one problem then it is always easier to fix. Multiple problems can be tougher.
      I would deal with getting the lights to go green again (battery?) and if that doesn’t fix the motor problem then you will have to dive deeper to get it all on track again.
      Could be a pro is your best bet, but if you can tackle it yourself that would be great.
      Good luck, tell us what fixes it when it all set, Turbo.

  26. Tomas says:

    Hi! first I will say that I’m impressed over this on side, we have nothing close to this in Norway.

    Now my quest, I got my wife an impulse el 250w. When we got it was dead…. I saw some wiring was twisted/ and some broken under the seat. (some amateur assembler in the store messed them up under the monitoring) I reconected them and isolated it. Now the lights go on in display but motor doesn’t work. This is a brand new bike never been used… The store gave me my money back and said to keep the bike. I noticed that 1 of the wiring pieces I reconected was to the deadman brake safety switch. What do you think about this? If the fuse is gone there will be no light, yes?

    • Tomas, from your description it is kind of hard to say where you stand on this bike. Without a doubt, a malfunctioning or incorrectly wired safety switch on the brake levers can easily keep the motor from running.
      I’m am not familiar with this E-bike so helping can be tough. Some makers will offer wiring diagrams with the bike or on-line. I would contact the maker to see if it is possible to get a wiring diagram.
      As far as a fuse goes, if the one in the battery is bad then nothing on the bike will work. There is a possibility of another fuse in the wiring harness or in the ECU (electronic control unit) that could be bad. If there are bad fuses, replace them with the correct ones, never bypass or wire past them.
      On top of what you have already done, I would consider contacting the maker for a manual and/or a wiring diagram and any other info they can give you.
      Good luck, let us know how it all works out.

  27. Tomas says:

    im stripping the electric system down right now (reopening the wiring i fixed, taking out the Ecu ect.) i notise fast that the sensor for speed? on a little plastic plate with the nav pedals was toutching the plate. can that stop the motor? because i know it to need little space for reading the holes hall sensor (im car mechanic so hall sensors not new to me) i just thinking laud here because speed limit= motor power !?

  28. Tomas says:

    by the way correct system on bike is a front Hub 250w (european limit) pedelec and battery 25.2 10ah lith ion. (all this i learn from u side thx)

    • Tomas says:

      hmm Cant get signal from pedal sensor when i put multimeter on black/red and start pedaling. im i doing it wrong? brand new sensor only rewired the cable on it

  29. Tomas says:

    ok stopped clowning now

    battery checket its perfect

    Ecu ohm checket its perfect

    hall sensor checket its perfect

    cant belive its the controller ….every light is working and switch to speed 1 speed 2 speed 3 is working

    the only thing i know is left is that stop handle cut switch… i cant get it ohm what im doing wrong?

    and do u have anything i may have forgotten?

  30. John OBrien says:

    Hello please can you help? I have a LA Bulky electric bike. And the thottle was not working properly so I sent away for another. It came the other day but it has 4 wires red, black, white and blue the original one had 3 black, red, brown. I have tried a various connections and it just won’t work. I have Googled it and I am still not getting anywhere. Thank you.

    • Hi John, I have no knowledge of that E-bike and a Google search didn’t help. My first thought is how you knew the throttle was having a problem. It is mechanically broken (loose or not moving smoothly)?
      As far as the wires go, some throttles work differently then others. Also some have auxiliary switches built-in that have additional wires from them.
      If you can get no answers from the maker (of the bike or the throttle), then I think a discussion with Pat at San Diego Electric Bike can help. He has done hundreds of conversions and repairs. He should know what wiring changes might be needed. I am thinking you were sent the wrong part, yet maybe it can be adapted to your E-bike.
      Good luck, let us know what it took when you know.

  31. Ryan says:

    Hi, I have tried over and over to get my bike to work, and I just cant figure it out.

    I currently have a 48v 1500w brushless motor which came with a matching controller and throttle. My batteries are a home made 48v 14Ah SLA lump which gives ~50V so no troubles there.

    Anyway, I’ve attached the hall sensors, the 3 phase for the motor, batteries and the throttle all up to the controller and I’ve gone to start it to get a spin out of the motor before putting it all into the bike, anyway – no spin or noise. I checked and got no changing resistance out of the throttle (red, green, black wires), and checked the power to the controller – all fine.

    A second connector “Powerlock” (maybe for door locks?) has +5V through it (yellow, red), then there is a “Charge” plug (red, black), “Braking”, “Brake lights”, “Indicators”, and lastly “Stalls” (grey, black). What could the “Stalls” plug be for?

    I only received these parts today and I’m really bummed out I can’t get it working.

    Any help would be greatly appreciated 😉

    • Ryan says:

      I just tested the throttle with a 4v source, its fine

    • Ryan, at this point I can only tell you to contact the maker or supply house you received your equipment from. I would think they would offer it with full instruction info that explains all the connections and options it offers. And if they are reputable, they will have someone you can speak with that can explain their equipment in a way that will help you bring it to life. There is always a chance they sent you a faulty part, but chances are you just need to work though the details.
      Running your motor off the bike doesn’t sound like the best of ideas. Also, I have given up on SLA batteries quite aways back, and in general wish everyone would.
      Let us know how it comes together. Without more info there isn’t much I can do. I do know a few E-bike conversion people that might be able to help if the supplier can’t.
      Good luck, Turbo.

  32. jono says:

    Hey Turbo, my cable plug from my hub to battery, the plug melts, do you have any ideas on this problem?

    • Jono, resistance (in wire and connectors) causes heat. If the connections are getting bad, they will heat-up and get worse. There is a possibility that the connectors were not high enough capacity to start with. It could be that they started getting dirty (inside on the actual wire connectors) or loose and that started your problem.
      The other thing to consider is that the amp draw could have increased due to other problems. There are on-bike meters and test meters that can tell if you are drawing too much juice through your wiring and connectors. If that is the case, it could damage other components too (such as the motor–ECU—battery). If you are drawing too much juice it would most likely have to due with binding in the bike’s or motor’s bearings, or even dragging brakes. Check to make sure everything spins easily.
      Have you noticed if your motor is getting hotter than normal during use? That could be an indication of excess amp draw.
      If the draw isn’t excessive, then a new high amp capacity connector soldered into the harnesses could solve the problem fairly easily.
      If you need info on the meters and amp draw, try the Endless Sphere forum. They are on Facebook too.
      Good luck sorting it out, let us know what fixes it, Turbo

  33. Andy says:

    Hi, I have an EVGlobal 36V ebike, has been working well for more than 10 years, but recently replaced a battery and I have a problem, two new batteries have failed, driven down to near 0 V and will not charge. I wonder if I have a short that has damaged these batteries.

    I checked continuity on the main power wires in the battery cavity with the main power switch turned off, and it shows <1 ohm on the circuit, suggesting that the circuit is closed. It seems like the circuit should be open when the main power switch is turned off. There are no accessories or other components that should draw power (horn, light do not work, etc). FYI, the bike has otherwise worked well in last few weeks, runs just fine but twice it died abruptly (no warning about low battery), and the battery appeared to be damaged.

    I'll open up the frame and start looking for a shorted wire somewhere, suggestions welcome. Thank you! Andy

  34. Hi, I have a Cyclamatic gte and am not getting power assist when I pedal, I have to use the throttle to get any power, do you have any idea what is wrong?

    • Paul, thinking your electronics are fine, I would suspect the mechanism (sensor) at the pedals that sense the movement there. The wire to the sensor could be damaged or un-plugged. Also the black wheel that turns with the pedals (with the magnets in it) could be too far away from the sensor.
      Of course the problem could be with the electronics, but from your description I would suspect the above items.
      Let us know what you find that fixes the problem.
      Thanks for reading and getting involved, Turbo.

  35. Gawain Judkins says:

    Hi Turbo I have just brought a secondhand Cyclamatic Power Plus. The problem I have with it is when i put the key in all the lights come on but there is no power to the motor. On turning the bike upside down I noticed that there is a broken wire 1 black 1 blue and 2 small holes on what seems to be a bracket to hold something on the right hand side of the pedals. Could you please tell what this would be called and what it does please as im a complete amauter when it comes to ebikes infact if I can get this one running it will be my first ever ride. Many thanks. Gawain

  36. Gawain, not being familiar with this brand of bike I can only speculate what might be going on. A true pedelec has no hand throttle and will only power up the motor when the pedals are turning (a general statement for most true pedelecs). So they need a (Hall) sensor on the bottom bracket, and a round plastic disc with magnets in it that turns with the pedals.
    I would think that missing item is the hall sensor. It is hard to find specs and close-up photos on E-bikes. The web is a fabulous place to get info.
    Have you done any Google searching on this bike? On who might offer parts (and advice) for your bike? That would be my first resource. Also, finding someone with a similar bike might help too.
    Endless Sphere on Facebook and the forum on the web could help find someone who could photograph their bike.
    Let us know how it works out, Turbo.

  37. Steve says:

    I have an E-bike someone gave me. The wiring was a mess, but the motor works. We took the box apart in the front by the head lights and rewired it, but when I wire the lights up the motor stops working. When I disconnect the lights, the motor works.

    • Steve, coming by wiring diagrams for E-bikes is next to impossible. It does sound like a wire or two maybe isn’t hooked up right. Just swapping them around to check isn’t a good idea. The wire color coding on E-bikes isn’t always what you would expect either. Check the web if you can. Many E-bikes are what I can generic—with no brand name or info on the maker or model. Of course, that doesn’t make things any easier.
      The simple fix (it seems but ?) is to leave the headlight inoperative and ride. You can get a nice light that is battery operated.
      Someday the wiring on E-bikes might be more uniform, and some companies are offering diagrams, but for now it can be tough.
      I wish could help more, good luck.

  38. lynn johnson says:

    I have an electric bike, purchased 2010; I believe manufactured in 2008; manufacturer (assembler) no longer in businesss.

    Problem: After being plugged into charger, the headlight works, throttle engages the motor, wheel spins. But any resistance to the spinning wheel results in motor quitting, headlight shutting off. After being plugged in to the charger for a few minutes, the headlight on the bike will again work, but again the motor quits with any resistance to the wheel.

    Model is Road King 2500 Lsi; Eco Tech is the manufacturer. Eco Tech was formerly sold by the same people who now assemble Prodeco bikes. I did contact them, but they weren’t helpful.
    Charger: Not clear that it is working correctly the charging light is always green, never yellow.
    Controller: numbers on the controller 36V, 31.5A, 7A, 12A
    TAG throttle: Working
    Brake shutoff sensor: Seems to be working correctly
    Pedal assist (wheel and magnet removed because I did not like the feature)
    Connections: I checked the connections on the controller. They appear OK.
    Battery: LiPo4. I have had difficulty getting someone to tell me if the battery is faulty. One shop did say thought that one of the cells was low, but this was not definitive because another shop said the battery was OK. I am not sure what the volt/amp of the battery is. The battery shop wrote 41.4V on the bottom of the battery.
    Motor: No burning smell noted. Turns the wheel until you add resistance then it and the headlight shut off.

    Any suggestions?
    If it is the battery, how can I tell what type of battery I need to replace it with? The battery connects to the control box by setting on posts.

    I would appreciate any help. I have tried 2 different bike shops with no success.

    • Lynn, I would suspect one of two problems. One, the battery is just bad. For a 36 volt battery, 41 volts is a good reading. Checking the voltage yourself can confirm if that is what it has now. It can have good initial voltage, but have problems inside that don’t allow it to deliver the power (amps) the bike needs. It could be the charger, and that is also checkable (to a point).
      There are many places (online) that offer replacement lithium batteries for E-bikes, but it needs to physically and electrically the same. Make sure to get a new (matching) charger with that battery so they work as a team. Not all batteries (quality) are the same, so getting the lowest priced one might be worth a second thought.
      A knowledgeable person can test the battery and charger to see if the volts and amps are within specs.
      A simple bad connection in the main wiring for the battery, ECU and motor is a definite possibility. Look for discolored and overheated connectors. They can let some power get through, but fail under load. This would be the cheaper fix, but may not be the problem.
      The charger might be ok, because if the battery is ok and no juice is used-up, then it wouldn’t go to yellow when connected. Still, from your description, it does sound like the battery and charger might have failed.
      I wish I could do more, but it sounds like you need an interested expert to follow through with the check-up. Let us know what fixes it.

      • lynn johnson says:

        Thanks for the quick response. Unfortunately, I haven’t been able to find anyone in the area who is familiar with electric bikes.

        So, I did some more checking with a borrowed voltmeter.
        With a voltmeter I measured: charger is putting out 41.4 volts
        The battery registers 41.2 volts.
        Then, I turned the power on. The headlight came on as did the red battery indicator lights on the handlebars (I know theses are not accurate). The motor turned the wheel. I tried riding it, but as soon as there was resistance (my weight, 120 pounds) the motor stopped and all lights quit. I then checked the battery again, it still showed 41.1 volts. I immediately turned the power back on and the lights came back on and the wheel turned, but again quitting with any resistance. Turing the power off, seems to reset something.

        So, now I need to decide if buying a new battery would solve the problem.
        1. Is it possible for the battery to be the problem, even though it shows 41.1 volts?
        2. If the BMS was not working correctly, would the battery still show 41.1 volts? If it is the BMS, I would not try to replace the BMS, rather I would purchase new battery.
        3. It doesn’t seem like the motor is the problem, because the headlight also stops working when resistance is added to the wheel. Is this assumption correct?
        4. Is there any way to rule out a problem in the control box?

        Thanks for your help.

    • Lynn, I am leaning heavily to a bad connection between the battery and ECU. It sounds like when a load is applied, the bad connection stops the power flow. I wish I was there in person to help you make the right tests.
      Try to check the voltage when everything is hooked up and during the failure. If the battery voltage (at the battery) drops heavily during the failure then bad battery. If the battery voltage (at the battery) stays at 41, then a bad connection is probably it.
      Could be the ECU, but so far it doesn’t sound like it.

  39. artschaldach says:

    Reblogged this on artschaldach and commented:
    Good Day
    Recently I dismantled my motor to see how it worked(like a dummy) and after reassembling it no longer worked. I can give the motor throttle but it sounds like it is just spinning inside the hub. Teeth are all ok and the motor works. Here are some movies showing. Any help is appreciated greatly.

  40. Boris Lino says:

    Please help me.
    I have a Crystalyte tc100 with 72v 20Ah battery. It was all working very fine, but suddenly the motor stopped working!
    The cycle analyst seems to work, battery too. The light of the control is also on. But throttle doesn’t work!
    More surprising, if I try to push the bike, or to pedal normally, there is a huge resistance (much more than usual when motor was working). It resists as if the motor was willing to brake by itself.
    More surprising, if I disconnect the motor (if I disconnect the bullet connectors between the motor and the controller), then that resistance disappears, and the wheel can spin normally.
    Whether the battery is connected to the controller or not doesn’t change anything, the motor resists a lot when bullet conectors are wired between motor and controller. And the motor will behave normally if bullet connectors not connected.
    Please, can anyone here help me?
    Thanks a lot!
    Boris, France

    • Boris, good job getting a lot of info on your problem. It might seem obvious to say, but it seems from your description that either the motor or ECU have failed. The problem you are having is one I haven’t come across before.
      I would contact the maker and supplier both to see if they have any insight to what will bring it back to life.
      Here are a few thoughts—judging by your description I would suspect the ECU more than the motor.
      And, some E-bike systems have security modes that can make the motor go into full regen (making the motor very hard to turn). They can be activated in different ways, including the simple act of removing the display head. It is possible you have accessed a security mode without knowing it.
      Wish I could help more, but I (and my readers) would be interested to know what you end up finding to fix it.
      Good luck and thanks for following along (and asking here for help.

  41. cloushan says:

    Hello Turbo Bob, perhaps you could help me. I recently received a 2012 Ecoped Pulse, and I am wondering if you happened to have a wiring diagram hanging around? Thanks very much. Great Blog, excellent, glad I found it. thanks 🙂

    • Cloushan, not wanting to disappoint you or talk down your machine, I do have to say this is way off my radar. I kind of consider electric scooters like this fake E-bikes. It isn’t a bicycle, but designed to thwart the legal bit by adding some useless pedals and a chain. Still, they are way better than gas powered vehicles. On the whole the ones I’ve checked out are generally low-quality to the point of being unsafe and un-reliable.
      I went on-line to check it out (I’ve never seen or heard of this particular scooter). They showed a owner’s manual, but no wiring diagram.
      One would think that red wires hook to red wires and so on—but this is far from being the reality for so many electro-mechanical devices.
      I wish I could help you, but I can’t.
      My main interest in E-bikes are ones that are a true bicycle with a motor assist.
      Best of luck, thanks for reading and asking for help. Good luck with your search, Turbo.

      • cloushan says:

        Thanks very much Turbo Bob, and yes, these things are pretty much glorified crap, but it was a freebie for me and only 700kms on it so it will do what it needs to do for as long as it does it haha. I did figure out the wiring issue and can now take it apart and put it back together with ease (almost), but wow, they sure are flimsy and I can see how un-safe and un-reliable they can be, or are for that matter. I was riding a Bombardier Moped 35 years ago, and these fake bikes should not be on the streets at all as far as I am concerned unless they have at least a better standard of quality and workmanship and real peddles!! Nevertheless, thanks for your reply, love the blog, will study up, learn lots, and go from there 🙂 Have a great day!! ~shannon

      • Thanks for the return message. I hope soon you can move to something that will treat you better. In the mean time take it easy on this machine.
        All the best, Turbo.

  42. Santos Ortiz says:

    Hi Turbo Bob very nice blog. I’m having a problem with my Ecobike Vatavio which has a 36V 8A Li-ion battery and a 290W geared brushless hub motor. I’ve had it for almost four years but only ride it to work once in a while for a 5 mile round trip. I used to be able to make 2 trips before needing to recharge, but recently all of a sudden I can only get about 3 miles then all power turns off. The battery meter goes from full to half then to empty in a matter of seconds while riding. After turning the key to the off position for a few minutes the battery level goes back to almost full. I’ve tested the battery with a multimeter after fully charging it and it shows 40.6V. I’ve visually inspected the controller and wiring but can not see anything odd. Do you think that in this case it could be a bad controller or battery? I’ve been leaning more towards the controller being the problem. Any input would be appreciated.
    Thanks, Santos

    • Santos, That is a good lifespan for the battery and that was my first thought for your trouble. Yet from your description it seems like something else. Check your wiring very closely for a bad connection (signs of a heated connector is a good clue). It could be that the connections in the battery pack are at fault. Try to test the battery voltage during the failure. Hook up the voltmeter during the ride and monitor it to see if the voltage drops as it slows the bike. Under load the connectors could be failing—and then coming back with no load applied.
      Most E-bikes have a thermal shutdown mode that will reset automatically once they cool. If that were the problem then some binding in the motor or the wheels could be an issue.
      Still, it sounds like that isn’t what is happening either.
      If these other things are ok, then I think you might be right, the controller may have lived its lifetime and is ready for a replacement.
      Still—bad connectors under load would be what I would look for.
      Good luck, let us know what you find, Turbo.

  43. Elvis Fecteau says:

    I just bought an used electric bike for my girlfriend. It worked good but just only one problem. The light was on half but the battery is dead. She can’t use the bike and it needs to stop using for a while so it can be used again. Would you tell me why that happen?

  44. Elvis—it could be that the battery is no longer any good. If the battery has sat too long without a charge it will damage it.
    I really need more info to go on to help you find and fix the problem. Do you have a local E-bike shop that can help?

    • Elvis Fecteau says:

      I know of an electric bike shop. I bought this used one from a guy on Craigslist so I am not sure how long it has been sitting in the garage but when I bought, it the tires are flat. I tried to ask more info from him. I would like to know if it true to keep the battery topped off. Should I charge battery every night after using it.

      • With a SLA (sealed lead acid) battery it is very important to recharge immediately (see below though) after each use and to recharge it every 4-6 months if it isn’t being used. Keep it fully charged all the time
        With a lithium battery is best to recharge it when it is between 70 -40 percent of its normal charge. Always recharge it before a long ride, but if you make several short rides, you can wait until it is over half empty to recharge. Also, never let it get fully discharged or let it sit very near empty.
        Both types don’t like to be stored in very cold temperatures or to sit in the sun for extended times. After use let them internally cool at least a half an hour before charging. Plus, don’t leave it on the charger more than 24 hours. It should have a smart charger, so when the charge is done, disconnect the charger.

  45. Howard Stevens says:

    I have a Suzhou Xiongda hub motor 250W and a 36V Li battery. I have installed this myself but appear to have problems with the throttle. I get nothing happening for ages and then it takes off, stops and starts and sometimes wont shut off. I have checked the connections many times, and done a multimeter test on the controller mosfets (all appear ok), checked the motor wires for continuity (all ok) and checked the throttle wires which show 4-5V across positive and negative, but no proper voltage variation between negative and control wire on moving the throttle, which suggests this is the problem I think. What would you suggest? Can I connect the throttle wires with a switch and potentiometer, as some have done, and see how that works? How do you do that?

    • Howard, if it is a three wire throttle (and most I’ve seen are) then it should read between 0-5K ohms, and give opposite readings when off and on. By this I mean in the off position one set of wires will read 0 and the other will read 5k—-when in the full on position each set of readings should be the opposite of that. I do believe this is how it works, but I will recheck to be sure.
      All the throttles I’ve replaced were bad from being physically broken, not electrically. I would think from your description it is something else—connections or ECU.
      If you suspect the throttle then replace it (they don’t cost much), don’t jury rig something.
      If you just installed this (as a full kit?) then I would quiz the people you got it from.
      I will recheck my throttle testing—let us know what you find and what finally fixes it.
      good luck, Turbo.

      • Howard Stevens says:

        Thanks for your advice Bob. I suspect the throttle because testing the wires shows a voltage of approx 5 volts between red and black wires, but when using the throttle the voltage readings between the black and the central(green) wire are all over the place and never get above about 3V. This was not the case when I first tested it, so something has happened. When I checked for continuity there is an open circuit between the black and green, a reading of 1450 between red and black and 1050 between red and green. There is no resistance variation on using the throttle. I sprayed the throttle lever with WD40, but don’t think that should be the cause of the fault.

  46. gloria lonsdale says:

    I have a 2011 eco pulse e bike scooter. I used it once this summer and then when I went to charge it, it wouldn’t charge. I also have an emmo bike and I tried to charge my pulse with that one with the same voltage and it blew that charger up. Do you know what this could be?

    • My thoughts here (although I can’t be sure with the info given) is this. The E-bike scooter has SLA (sealed lead acid) batteries. From sitting they degraded to the point of not being chargeable. The other bike has lithium batteries. Even though they might be listed as similar voltages, they are not the same and the two chargers are not interchangeable.
      It is very important with any kind of battery to use the correct charger (the one supplied with the battery).
      I would suggest contacting the makers of each machine to get the correct replacement parts (batteries and charger) to get yourself back on track.
      Good luck, tell us what you find and what it takes to solve the problem.

  47. dorel says:

    I just climbed my E-bike up a hill. It is a brushless motor 500 watt, brand new. It doesnt want to work. There is no electricity going anywhere, no lights, nothing. What would be my next step?

  48. Seeing that its brand new, just take it back to the dealer you got it from—the full warrantee on your bike should cover it.
    Could be a battery fuse, maybe check that first.
    Let us know what fixes it or if you have further questions—good luck, Turbo.

    • kgnot says:

      Hi Bob, I have another problem .
      I drive alone but my E-bike crashed recently because the thief didn’t manage to stop, me chasing him.
      However now when I press full power on the throttle indicator goes to yellow. When I release the throttle it goes green. I have checked the battery again and again for broken connections but it seems ok. Is there a way to check for broken connections?
      Can a damaged or missing connection in the bms cause such behaviour? Control box itself?

  49. kgnot says:

    I found the broken connections between two cell clusters underneath. However if I connect one point(out of 4) it heats the connection so much it goes orange! How to measure if they are calibrated, the bat. Cells how is this possible? What could be the cause to overheat the connection?

    • kgnot—-you have pretty much lost me here. Hard to say where you stand on this.
      E-bike wiring is different on every model and brand, yet usually they make sense on how it all hooks up.
      Get a hold of a wiring diagram before you cause things to get worse—the best advise I can give you at this time.
      Good luck, Turbo.


    bike does not run battery charged put in nothing checked voltage from battery fluctuated open case pinched red wire at bottom of case cap screw contacted wire UN crimped tape wire perfect steady volts 26v put back on controller nothing not even lights on throttle took top cap of of controller red wire was small cut on wire taped it up rubbing against the metal frame piece that the male receiver plug that sits on top of controller wiring inspected in both items were shoddy i feel the whole system short it out never got power to any thing past the battery case receiver plug that i fixed have to peddle to work the wiring is the worst i have ever seen i would like it replaced 500.00 for a bike thats a real Chinese job my kids power wheels were wired better 28 years ago worked call me at ***-***-**** call me brought it thru ebay contacted ebay return policy program with this same MSG the item never worked junk

  51. Robert, I can’t make heads nor tails of your comment. It seems you bought a cheapo E-bike on E-Bay and are very un-happy.
    I do recommend against getting E-bikes on-line. Getting one from a reputable maker on-line can be safer, but if you can get one in person from a good dealer you will get hands-on help no matter what happens.

  52. policetac says:

    Okay. It looks like you still monitor this site. Excellent! 🙂
    I came here because I did have a specific question in mind. I wanted to know how come my throttle indicator lights were just flashing on and off while the bike seemed to have no power. I believe however that by reading your site, I have already been given the answers I’m going to need in order to finally get my bike going. Excellent job!

    But I’ll run through it quickly just to be sure okay?

    The bike is second hand to me, (not working) generic Chinese ebike. I have all the stats but for now I’m just going to stick to the basics. It originally had a Li battery pack, but I replaced it with a new Lead 24v 10Ah pack I wired up. (Battery pack works great.)

    You had an earlier poster who thought his over tight brakes might be an issue, but you said they don’t work that way. Funny. I thought the same thing might have been an issue. If I understand correctly though, the circuit that “shuts off” the motor closes when the brakes are applied? Meaning that removal of the brakes wires from the controller’s connector would leave that circuit “open” and therefore remove it from the controller’s circuit? That said, I will start by doing this on both brake circuits and retest.

    Raising the back end of the bike and testing in place. Good idea. On it.

    I still don’t have a working understanding of my multi-meter yet, so I’m having a bit of a problem testing resistance through the throttle. I’ll start with

    I also had a stray yellow wire coming from somewhere. (Controller.) Assuming it was a ground, I inserted it into another yellow wires connection. I’m going to remove this splice and see what happens.

    I’ll post my results as I get them and will check back in all day. Thanks in advance.
    (Sorry. I guess I didn’t really have a specific question.) 🙂

  53. policetac says:

    Okay. I just got back in from a test:

    No detection of additional torque or speed.
    Throttle lights still flashing on and off when applied.

    Work performed:
    Checked battery for charge – 25.67v
    Checked all connections – (Controller): Clean and secure (Includes battery plate)
    Identification and isolation of brake wiring – (Both front and rear.)
    Visual inspection of throttle wiring – Attempted Ohms resistance testing on this circuit
    Black to Red – 21.03 No change when throttle applied
    Black to Green – 9.88 No change when throttle applied
    Green to Red – 30.67 No change when throttle applied
    Continuity – None (Any combination)

    I am reluctant to test the output from the controller as I do not wish to blow my multimeter or any of the circuits within the controller. This reluctance comes from my ignorance of the OEM wiring “colors” and what they represent. (Ie. Black = Grd, / Red = Pos, / Green = ?)

    I have not yet built a kickstand, therefore the testing was performed while riding the bike.


    Any suggestions? Thank you.

  54. policetac says:

    I think it’s something to do with the motor. I’m getting a faint sound every time I engage the throttle. It sounds like a dull “thunk.” It is difficult to locate the exact position of the cause to this noise due to the sound traveling through the frame.

    Before I take the rear wheel off, and the motor apart I want to check into something else. I’m curious. Just outside the crank housing is a sensor that reads a magnetic disk attached to the crank arm at the base of the pedal arm.
    My assumption is that this sensor is used in order to ‘assist” the rider by engaging the motor only occasionally. (Ie. as each “dot” of metal on the disk passes the sensor, the motor engages. It disengages as it passes by until making contact with the nexrt piece in order. This would then add small “pushes” of power several times per revolution.)

    This disk is about 3/4″ away from the sensor though and seems to me as if there was no way it could be designed to operate in that way. They seem way to far away. But there does not appear to be any other way to mount the assembly. (Perhaps they do not have to be that sensitive?) IDK

    Anyway. I’ll stop until I get a reply. Thanks.

    • Policetac, what I’m reading here is the motor doesn’t work, but makes a faint clunk—and the throttle lights are flashing.
      As far as wiring, colors and wiring diagrams, there are no standards and few companies offer wiring harness diagrams.
      Being brushless motors you can’t just feed battery power to them like the old-school brushed motors.
      Without looking at my diagrams and notes, there are three wires that the throttle uses and the extra (4ht) feeds power to light the LEDs that are suppose to tell you how much battery charge is left. Most throttles are two variable pots (5K) that work opposite of each other.
      That disc is a part of a hall sensor system to signal the ECU to run the pedelec function. On a dual control bike the bike should still run if it isn’t working, but on a true pedelec it needs to work. The magnets should ride very close to the sensor, but not touch it. The disc on the pedal crank axle should be easy to move (by rotating in a certain direction) to get that distance right.
      On brushless motors there are three main phase (power) wires. They can be hooked in any sequence, but if the motor turns backwards, reversing any two should fix that. If there are other (smaller) wires they are the sensor wires. They do need to be hooked right for the motor to work smooth (or at all). On most motors they will run with just the main three—the other help the motor run smooth and start without roughness.
      Tearing down the motor isn’t always a good idea and I would think your problem isn’t there—unless you have some broken or shorted wires. If you take it apart make sure to get the internal freewheel back in correctly.
      When you write, try to be very specific with your problem and where you are with the diagnosis. Waiting to hear more. Good luck, Turbo

  55. policetac says:

    Okay. Here’s where I’m at.
    I moved the sensor disk closer to the receiver. (For some reason it fit perfectly this time???)
    I closely inspected all wires for cuts, weak spots, and bad or corroded connections. They all looked fine.
    I disconnected the brake wires from the controller circuit, adjusted the gears, and made sure the wheels were moving freely.
    I made and used a stand where I can raise the rear wheel off the ground during testing.
    I checked the voltage of my battery pack at test start, (25.34v)
    I then proceeded to test.
    No detection of additional torque or speed.
    (Something is telling me that the “thunk” sound is electricity hitting “something” in the motor.)
    Throttle lights still flashing on and off when applied.
    (Lights flash only when throttle is “on” and wheel is turning.)

    My questions:
    What could the sound be?
    What do I do next in order to diagnose and repair the problem with my bike?

    Thank you.

    • I am still confused when you say “No detection of additional torque or speed”. Are you saying the motor doesn’t run?—Runs slowly—Or only at one speed?
      The thunking noise—is it just once?—or does it do it a lot?—When it does it does the motor jump or change speed?—It sounds similar to a problem with the motor’s internal sensors or wiring, but hard to say at this point. Does the motor have three main wires only?—Or extra smaller wires?
      The flashing throttle lights indicates to me a bad ECU (electronic control unit) or possible a miss-wired system.
      I am still not fully understanding all your issues, but getting closer.

  56. RN says:

    Bob I have a problem with a Chinese made 48 volt 20 AH battery I bought in January. I maintained the charge in the battery until this month, when I began riding it. Then I noticed a couple of things after a few weeks of riding:
    1. Immediately after charging, the battery does not work on the bike. I have to wait about 10 or 15 minutes before it does.

    2. When I hit full throttle upon initial use of the battery, all the full charge lights were on. Now, one of them slowly dims and then comes back on. This is with a fully charged battery.

    3. This is the worst one. Two days in a row now, while I am riding, the battery suddenly goes dead without warning. (Fully charged) Then, about 10 or 15 minutes later, the power comes back on. Then, maybe a half hour later, the same thing happens and I have to wait for the power to return to the battery.

    Is there some kind of auto-shut-off mechanism in the battery causing this? Can I correct the problem or is a new battery in order? Remember, this battery has only been used a few weeks. Thanks for any help.

    • RN, it sounds like there is a connection problem inside the battery wiring. Possibly the cell wiring itself, but maybe just the main wires that connect the battery pack to the connection to the bike. Some voltage testing might help determine if that’s the issue. Keep in mind that it may not show reduced voltage unless it is under load.
      I would contact the supplier of the battery for a warrantee replacement. They will want you to have a working item you paid for.

      • RN says:

        I contacted them and they offered to send me a new BMS and asked if I knew how to change it. Is this the way to go? The cells are fully charged, they are not the problem at all.

  57. Could be, and if not you can do some voltage and continuity tests while you are in there. Some battery cases are easier to get open than others. It sounds like they think that is the problem.
    I am kind of surprised they would want you to get inside the battery case. There is danger lurking and I would think they wouldn’t want you to get involved with it. Do you think you are up to it?
    I don’t see why they just don’t swap out the complete unit to make sure you get a good battery, you stay safe, and you save time and trouble.
    I would push for them to send you a new and tested battery, you spent the money with them and that what a warrantee is all about.
    Let us know what happens.

  58. RN says:

    Is replacing a BMS difficult? I don’t know how to test voltage. Can the old BMS be fixed? Could an ordinary electrician fix it?

    • A true expert with lithium E-bike batteries could take on the job. They can be hard to find.
      Without a doubt, return the complete battery and ask for a new tested replacement. Let them do with it what they like, but don’t accept anything but a new one that will give you the correct quality service you have paid for.
      This is the best advice I can offer.

  59. RN says:

    Yesterday they said they will send me a new BMS. When I asked for a replacement battery, citing my inexperience with these things, I received no answer. Suppose they sent me the BMS. I cannot send the battery now because then I won’t have it to install the BMS I’m about to get..If I send the battery and they don’t send a replacement battery, then I am screwed. The paypal payment for the battery was in December and they are in China. I am trying to be efficient and practical here.

    Is replacing a BMS protection board something I can learn to do? How do I test the cells to ensure they are not really the problem that’s causing the BMS to shut the battery down? Voltage and continuity testing, how and where do I do this? Seller is unresponsive to all these queries, and I have to get this thing running even if it means DIY, thanks for any help.

    • And, I did a quick search on the web and You-Tube for some helpful info on your battery problems and BMS replacement—couldn’t find any. You might spend some time in this direction yourself.
      Still, a new battery that works and is warranted is your best bet. Bite the bullet so you can ride your E-bike with a smile.

  60. And RN, such is the nature of dealing directly with China to save a few bucks. I see and hear the stories all the time.
    I can’t teach you how to take on a knowledge of electricity, testing tools and procedures and your next step. Each BMS is different and each battery case mounting is different too. What you will find inside are many cells that hook together in both series and parallel to make up the battery. Each cell will be connected to the BMS separate of the main wires that feed the bike. Each cell is ratted at 3.14 volts, but it is not un-common for them to read 3.4 volts when fully charged. Each cell should have the same voltage (part of the job of the BMS). The wires may or may not be soldered (and need a soldering iron to be dealt with).
    From the beginning I felt you had a bad connection in the main wires, not the BMS. I wouldn’t be surprised if the BMS is fine and the problem is in the main wires and connection (either in the battery or the ones that connect it to the bike).
    Contacting an expert to take on the job is my recommendation.
    Even stronger I feel you should get a good battery from a reputable shop that can back you up and any product they sell. This is so important. Even if you buy stuff on the net, make sure they are domestic and have a great reputation for things like this.

    • RN says:

      I just heard back from them, and the lady said they are waiting for word from the boss. So maybe they’ll swap it out.

      In the meantime, I bought a multi-meter and set it to DC and checked the voltage of the battery. It reads 24.9. However, now, when I plug the battery in, there is no power at all. It was charged just a several days ago. It cannot be the connections outside the battery on the kit; these have not been touched, so there is no possibility they were damaged somehow, and it WAS working during the on and off phase.

      Any thoughts appreciated, thanks.

  61. Dennis Horseman says:

    Hi Bob. We have a french easybike easycity, the speed display just shows 00 when riding although everything else works fine. It has the same 4 button lcd display unit as used by pedalec. Any pointers to why it is not working. I have tried contacting easybike without success.

    regards Dennis

  62. Hi Dennis, thanks for following along. The simple fix would be if this bike uses a spoke mounted magnet to activate the speedo—many E-bikes do (sometimes on the rear wheel). If that is the case then the magnet might need to be adjusted so it runs closer to the sensor. Or maybe the senor is loose or has a bad wiring connection. This is the same as most wired cycle computers.
    Many of the newer or more complex E-bikes use a sensor inside the hub motor for this function. If that is the case and the wires are all hooked tight, then some time with a tech will be on tap to bring it to life.
    If everything else does work and there is no tech nearby, then just adding a cycle computer might be easier and cheaper.
    Good luck. Turbo.

    • Dennis Horseman says:

      Thanks for the quick reply. It does not use a spoke magnet so I guess the sensor is in the hub. It has now started cutting out around every 20mins. Press the on button on the digital display and it is fine again. I have checked all of the connections and they seem fine, are there connections inside the box that the battery slides into? I have posted a link to show you the bike in question.

      Regards Dennis


      • Well Dennis, it seems that the problem is getting worse. At this point I might think the ECU (electronic control unit) is the culprit. Although it isn’t my favorite way to go, swapping out parts in order of importance is the way many techs find and fix the problem.
        It could be the motor, but it sounds more like the ECU.
        I get the impression there is no Easy Bike shop near you. Getting the bike to an expert would be my first choice. If it is under warrantee still, then the company should help you decide which parts are suspect and ship them to you (maybe one at a time) until it is running like new again.
        Many of the simple fixes I have outlined in these two articles don’t address your problem directly. If you have truly checked all connections and the simple problems, then replacing the ECU is next.

  63. John R says:

    Hi: Glad I found this site. (Turbo Bob`s) Hi: Received my E bike kit today. Followed all instructions. Was very easy to install. When I push the button on the LED to turn it on, all lights light up, but the 4 lights to show that the battery is fully charged go out after I release the button. The mode button works and shows all modes when button pushed. (low,med,high). I double check all connection and made sure the battery was fully charged. BUT when I turned the throttle nothing happens. All connections to the controller went on were they were suppose to go, double check that too. Don’t know what else to check. Sent this email to E bike and they sent me another throttle and controller, but still have the same problem. Can you give me any suggestions to check?
    Thank You John R

    • I would imagine they have given you some more help after still having the problem. I can’t come-up with any real idea of what to check next with this info.
      I think, seeing that it is all new, returning the entire kit for a complete (tested) replacement would be the best option.
      I hope that is what they offered you.
      Let us know how it comes together, good luck. If you have additional questions as you work through this I would be glad to help (with more information too)

      • John R says:

        Hi Bob, Thanks for the info. So I contacted them and they sent me a new controller and every thing works OK. I am glad that was all it was or I would have ask to send it back, but I would have to pay shipping. Thanks again. johnv45 ( it is a real nice unit I am glad it works)

      • Glad to hear that all is well—enjoy the ride!

  64. RN says:

    Hi Bob,

    I finally got the seller in China to consider replacing the battery. Here is what happened with the battery: I noticed a funny smell, like tape, coming out of the battery. Then I noticed I accidentally cut one of the cells open. A few days later, I noticed the cells were warm, even though they hadn’t been charged in several days. So I disposed the battery, even though the cells measured 3.4 volts. Was that battery still good? What did the 3.4 voltage indicate?

    Also, I saved the old BMS. How can I check to see f it is still good?

    Appreciate your thoughts,


    • Any cut cell is bad. I do hope you got it to a recycle center for correct handling.
      A warm cell indicates a definite issue (one that could escalate).
      Old lithium batteries (that are good) are good for power storage and that use is getting more popular.
      Just hope that your new battery works perfect and the smiles will come again.

  65. Dennis Horseman says:

    Can anyone please advise me where I can purchase this control unit:

    Compact box
    36v brushless
    G3M 202-1592-16
    LSW 352-82-1. X1204016660

    3 white plugs
    1 black plug
    5 green sleeved push connectors (1×3 & 1×2)

    The hall sensor (black plug) has 6 wires (I think the extra one is for the LCD)


    • Dennis Horseman says:

      If nobody can advise on the above does anyone have an email or website of somebody in china who supplies controllers to the public.

      Cheers, dennis

      • Dennis, my local supplier and E-bike guru is Pat at San Diego Electric Bike. I have shared his info and link before. You can Google the shop (to get contact info) to see if he has what you are looking for.
        Also, the people on Endless Sphere (the forum and Facebook page) are a good source for finding suppliers for E-bikes and the parts needed.

  66. jeff says:

    Hello, I recently replaced my damaged charger for my 48v 15ah Li-Ion E-bike battery . I replaced it with the exact same charger but now it won’t hold a charge at all. The throttle lights and the motor will run when the charger is attached and plugged in the wall. But as soon as it’s unplugged there is nothing.
    My bike did sit for 2 weeks with a low charge while I waited for the charger to be delivered.

    Any advise would be appreciated.

    Thanks. Jeff

    • Two weeks shouldn’t be a problem, yet it is possible. Turning on your bike with the charger attached is not recommended.
      If everything worked before the charger problem—then I would suspect it to be the problem in this situation. By exact same charger do you mean direct from the bike’s manufacture?

  67. Pera says:

    Hi, I have a 250 watt 36 volt front wheel kit that I installed, and this would be the 3rd one I have done for my family, and all but this one have been great . Hope you can help with this question. Here we go. I’ll try to be as specific as I can. Everything is connected properly and it is working when the wheel is in the air (off the ground with no load on the wheel), but with it on the ground and weight applied it seems to kick like it wants to go in reverse for an instance. Just a tiny bit but it goes forward making a knocking sound and it goes away once it reaches top speed. Any idea what can this be? I’ve tried other controllers and throttles, even another battery pack and it does the same thing. Plus with the sensor plug unplugged it works (meaning the 3 wires being connected only) but does the same thing. It doesn’t run smoothly from the start but goes away and runs smooth at high speed.
    Help Turbo please!

    • Pera, I would be pretty sure you are having a sensor problem—or they are incorrectly connected. Have you contacted the firm that you got the kit from?
      If you are sure all the sensor wires are right, then a motor replacement is in order.
      Let us know the outcome, Turbo.

  68. Pera says:

    Hi Bob, yes all connections are correct and as you prob know by now it’s a Chinese kit that I got for a good price ($112.00), and it would cost almost as much to ship back but, I checked the hall sensors and they are working plus I spun the wheel and shorted two of the three motor wires together at a time and got resistance from the wheel (wheel stopped spinning freely) so all looks fine to that point. The thing is that it’s working and not making that sound as much. plus we rode it today all day on a 45 mile run and it performed very well, tops out at 20 MPH avg speed rode 13 – 16 on three 12 volt 10 ah SLA batteries and the voltage after the ride was 29.68. I know it sounds amazing because our friends have expensive E-bikes and avg 15 – 20 miles per charge, and another thing is we have now 3 bikes all 36 volt packs and none of them charge over 33.9 volts. and yes they are the chargers that are provided with the kits and are SLA chargers, Thank you for the quick response your doing a great job bringing us to the new transition one step at a time and leaving no footprints and getting ppl out there to enjoy this beautiful world and way of life 🙂
    Pera xx

  69. James says:

    Please help. My 48v 1000w hub motor and thumb throttle work, but there’s no power given. When I turn on the throttle the 3 leds come on and the batteries are fully charged. But as soon I turn it on (the throttle), the controller shows a red flashing light. I mean the red light isn’t rapidly flashing, but its blinking. And if I pull the brake (it has a cut-off switch) the red flashing light speeds up. Please, I need to know whats wrong.

    • James, your description leaves me a little baffled. You say the motor and throttle work, yet no power is given. Does that mean it’s not working? Sounds like it. More info and a more descriptive story is required.
      Some ECUs (not that many it seems) have a LED to read out trouble codes (with a blinking sequence) when they aren’t working. Manufacture info (hard to come by) can clue you in there.
      Make sure to check all the connections, check the electrical operation of the brake cut-off switches, if they are good I would suspect the ECU (Electronic Control Unit).

  70. Jana says:

    Hi Bob, I have e scooter 48v/250w motor. My main wiring harness had been damaged by a rat, so I changed the new wiring harness. I am facing a peculiar problem, when I put the throttle motor won’t move. When I apply brake the motor started running with my tail light ON. When I release the brake the motor comes to stop. Please help.

  71. Jana, my questions run from—-did you use the exact replacement wiring harness from the maker of the scooter? Did all the connectors and wiring colors match?
    It sounds to me that one or more of the connections aren’t right. It is possible that in a multi-connector the wires are not in the same sequence. Did you take notes or photos as you removed the old harness?
    If it was working fine before and everything is hooked up right it should be fine. I think somewhere a wire or two got switched around.
    Let us know what you find, Turbo.

  72. Alex says:

    Hello Turbo . Great blog, lots of info. My question is regarding the battery, a 36 volt lithium. Would low voltage stop the motor from working entirely? I have done all the tests possible regarding sensors, checked connections, continuity, etc . When the battery claims to be fully charged I only get 32 volt output. The charger output is 41.2 volts. Is that about what it should be?

    • Alex, 32 just isn’t enough. A fully charged lithium 36 volt battery in good shape should read about 40 volts. It does sound like the battery is your main issue.

      • prashant says:

        Hello Bob, I am from india , I have a Ultramotors UK made E-bike. I have purchased a 48v 20ah LiFePO4 battery pack from China. Everything is working fine. It gave me 65km per charge, but after 3 months it is giving me only 25km per charge. I checked the battery but it is working fine. The BMS is stopping the battery before it is empty. It seems there is some overload from controller or motor, so BMS is stopped when charge is still 52.6v. I have opened the controller but there is nothing to suspect. It is clean. I checked the motor to controller connections, the hall sensors are toggling 0.3 to 4.0 volt when the wheel is spun. One of the three phase wires shows some melting, and I am not able to open the motor,
        As I am afraid if the problem might outside of motor, please guide me

  73. Tim L says:

    Hi Turbo I have a 48V 1000w kit with a 48v 25ah Lif Po4 battery. The other night it quit running . When it is plugged in everything is fine but when it is unplugged the it flashes on then turns off. Your assistance would be greatly appreciated. Thank you in advance.

    • Tim, this info isn’t enough to go by. One thing in you question that catches my attention is that it sounds like you are plugging in the charger to the battery when the bike is turned on. That generally isn’t a good idea.
      Good luck—and a more detailed run-down might help me help you.

  74. Parshant, I would suggest installing a Cycle Analyst. I will give you all the info you need to decide if there is an issue with motor or controller draw. And it will tell you real time voltage and amp readings too.
    Good luck—plus make sure to deal with the overheated phase wiring once the problem is located and fixed.

  75. msjunk says:

    1. I have a Cyclamatic 24V 250W ebike. The power cuts out under load when battery voltage drops from about 30V to exactly 24V. I suspect the battery is getting weak, but controller cut off is supposed to be 21V.
    2. Can I replace the 24v 10ah LiFePO4 battery pack with a 36V 10ah version, and use the existing controller and 250W motor?

  76. KT says:

    Hi Bob,
    I’m new to this great ebike craze.
    I just received my xiongda 2speed ebike kit.
    I installed the kit and connected all the wiring.
    My battery is a 36v lifepo4 pack and the controller says 48v input.
    The problem is, the lcd panel won’t turn on.
    I checked all the wiring and they all good.
    Is this because I’m using the wrong battery? 36v instead of 48v?

    • KT, you’ve solved your own problem. Any decent controller for a lithium battery has a voltage cut-off to protect the battery voltage from dropping into a level that can permanently damage it.
      Some controllers are programmable for voltage, but it sounds like yours isn’t.
      Get a good quality 48 volt battery and you should be good to go.

  77. Marek says:

    Hi Turbo Bob! Help please! I bought an electric bike kit, 48v 750w motor from China. Range 40 km. But it only did max range 3.5 km, then it cut-off the power. When I put the bike on a stand, the bike runs full speed for an hour nonstop, no problem. When I sit on it, only 3 km, my weight is 80 kg. Since then bike has deteriorated more, and now I can’t turn it on. When I press the on button, LCD only flashes and it looks like battery is full. Some times error nr 3 flashes, which is motor hall signal abnormality. A check on the battery reads 52.6v. Battery won’t let me charge it any more. The seller send me a new controller, and after first ride the controller got very hot. You couldn’t touch it. Don’t know what to do any more. I checked all the connections, seems to be fine. Please help ! Regards Marek

    • Marek, I must say one more time, something I say so often—the key words of your problem are—“From China”. Without a local sourcing, any issues like you are having leave you with no one to help. Could be some connection problems—could be a bad motor.
      Of course all this stuff come from China, and getting it direct can save $—yet when you have an issue, all that money saving goes away and the stress involved is bad news (and the time it takes to wait for foreign shipping).
      Sounds like the battery is good (fingers crossed—it is lithium right?—stay away from sealed lead acid.). At this point I think I would consider starting again and getting a complete kit (minus battery, unless you have an sealed lead acid)) from a known American (or the country you are in) company that will back you up down the line. You will get Chinese gear, but, but ones that are backed by a solid company with customer support that is semi local (with a kit they know is from a reputable maker from much experience).
      I hope it all comes together and you don’t get discouraged. Let us know your next step and level of success. Having a fun, dependable E-bike is worth the $ and time.
      Good luck, Turbo.

  78. ken pratt says:

    My electric bike throttle lights have stopped working and my bike does not work what could be the problem

    • Ken, this is way too little info. Read this two part article to see what you can find on your own. If that doesn’t help, get back to me with some more detailed info—and results of what you have found so far.
      Good luck, Turbo.

  79. steve says:

    I have green yellow, its one wire, then a yellow white, its one wire. Finally a brown wire hi and low beam switch connecting to a red blue and black headlight for a ebike. how do i connect them?

  80. steve says:

    Hey, I bought an emmo x series ebike. 30L lithium battery, and when I turn the key nothing turns on. The thing is fully charged. I don’t know what’s up, please help.

  81. Steve, any new bike you will buy is fully warranted. Just dial up the dealer you got if from and they will sort it out. Most good E-bike shops will offer a truck to pick it up for the warrantee repair.
    I am really hoping you didn’t buy it from a distant on-line site. I am big on recommending against that. If you did, then some major shipping costs might be involved. Maybe you can get them to cover it.
    My on-line search makes me think this is an electric scooter—not an E-bike.
    Much of what is in this article is good for those, but not all.
    It could be something simple you can find, but then again it could be a bad component or semi-major problem that needs to be diagnosed and then repaired professionally.
    If you really need the help, then tell me what you found as you followed the steps in the two articles and I will do my best to guide you. My best advise is to let the maker or dealer find and fix your problem.

  82. george says:

    Hi, LED display lighting up really bright but will not stay on once you take your finger off the button. Any ideas please?

  83. I still am not sure what to say. Are you talking about a LED headlamp on an E-bike? On what kind of E-bike? What about the tail light operation? Does it have a tail light that works when the headlamp is on? On most E-bikes I have dealt with, the ECU and display unit work together to power the LED headlamp. If the LED is good (and it seems it is), then the problem is part of the bike’s power system.
    Still, I’m not sure what you are asking.

  84. Hi there. I have a folding E-bike, it was running fine last season. I stored it indoors for the winter, but this year now the battery meter lights up but the minute I try to take of it jumps to take off then, its like its shorts out and stops going anywhere. The battery meter lights die, but if you turn it off and on again the meter lights back up again and the same thing happens. It dies the minute you try to take off. The battery is fully charged, how ever if I go full throttle and then turn the key, the battery meter will light up and it doesnt go any where but if I give it a starting roll, and then quickly let go and put back full throttle it will drive but the battery meter starts to short out and od lights up? Is that the ECU. the batt shorting, the ign, or the hub/motor? Any help would be greatly appreciated !!!

  85. Mike, my first thought as I read your description was a bad connection between the battery and the bike. The heavy amp draw when first starting out could make that connection disconnect, yet still leaving enough connection for the small amount of power to run the battery meter lights after you turn it back on and off.
    I would check for corrosion or the such on those connections. It is also possible the internal connections (or fuse) in the battery housing could be doing the same thing.
    Yet as I read further, it does seem your next concern (if those connections are solid) is that the ECU could be acting up.
    Also, some of your description could say bad sensors in the motor or the connections to the ECU (the smaller wires to the motor). Yet your whole description says that isn’t the problem.
    Still, I would first suspect the larger power wires between the battery and the ECU (switch too)—and between the ECU and the motor.
    Good luck find the issue—let us know what you find.

  86. bobby wong says:

    I have purchased one of those 48v 750w chinese motors. It came with 2 brake levers, a thumb throttle, a ECU and the hub motor wheel along with four 12v batteries. Also is thingy to attach to the peddle crank. I hooked up every thing, plug and play. But it won’t light up or turn the motor or anything. Also, are the shutoff brake levers and the pedal thing needed?

    • Bobby, either there is a defective part, or some connections are wrong (or loose). Maybe too, the batteries or fuse is causing the problem. I would suggest checking the battery voltage at the battery and also making sure that power is getting to the ECU.
      Of course while you are doing that, recheck all your work with a fresh perspective. Maybe the issue will surface and all will be well.
      The motor cut-off switches are there to help you stay safe. The pedal sensor mech could be set aside, but having the automatic pedelec function can make for a better and smoother ride.
      Good luck getting it to come to life. I do hope that all the components are good and you don’t have to go much further.
      If you do have a bad component, there is a chance the company you got it from will replace it. I do recommend getting E-bikes and E-bike conversion kits stateside from reputable companies that are there to help with issues and help you solve them.
      Let us know what you find to get that bike on the road.

  87. Robert says:

    I bought a 48v 1000 w kit last year and a battery. It worked fine until January. Then I bought two different kits each 48v 1000w from two different sellers and NEITHER ONE works. Is this a battery memory issue? Because the battery worked fine with the old motor that stopped working in January.

    • Robert, it should be pretty easy to determine if the battery has the proper voltage to run these systems. Although there is more to it than voltage, this basic test on the battery is where to start. Try re-reading both articles to see if you can make the test yourself. If not, enlist the help of someone who can.
      If you have been using SLAs (sealed lead acid), I strongly recommend you move to a modern long-lasting lithium battery.
      Check in with what you find, Turbo.

  88. Bigdan says:

    I have been riding a brushless front hub motor bike made from the hill topper kit. The motor is a planetary-geared BLDC PWM 250w 24v brushless front hub motor. I’ve recently started to have problems with shaking and speed. When turn the wheel by hand (unpowered) I notice at certain points it becomes hard to turn and when riding this is felt by an off balanced wheel feel and audible and visible shaking.

    Is this a unfixable hardware issue? I have already purchased another hub motor to replace, but I would like to repair it if possible. Any thoughts?

    Big fan of this thread, tried looking through it to find a solution. Keep up the good work.

    • Big Dan, most likely the internal gears are having an issue. Maybe some loose sensors in the motor could be the problem instead..
      It isn’t too hard to open most motors to see which it could be. I would get with Hill Topper for their opinion
      If replacing the motor solved the problems, than you can be sure that is where to look. A bad ECU can give problems, but not really like the ones you have been having.
      Let us know how this investigation and repair goes.
      Thanks for the thumbs up. I hope you are having as much fun with your bike that I have with mine.

  89. SK says:

    Bob I need your help ASAP. I know there are so many questions on here, so apologies if this has been answered already.
    My E-bike is a week old. It is a cheap £600.00 folding E-bike 250watt brushless (legal limit in the UK) . It has power cut-off brakes (rear electric drum) and throttle and pedal assist functions.
    All the lights on the display are full and the front light and horn are both working, but the throttle and pedal assist have no function. The motor doesn’t even jerk or anything.
    No burning smells, no corroded connections or anything. I disconnected the brake lever wires and still nothing from the motor. I disconnected the motor wires for a few minutes and then reconnected and still nothing.
    The charger fully charges the bike as the light changes to green.
    When I roll the bike backwards (non coasting), the motor feels ‘sticky’ and doesn’t feel smooth at all . It makes the ‘whirring’ sound however so nothing sounds odd .
    I need help dude please.
    Thank you.

    • SK, my first thought is to take it back to the shop you bought it from and get it fixed or replaced under warrantee. If it came in the mail you already haven’t followed my everyday advice on E-bikes. I understand though. Still, pack that baby up and make the company cover the shipping for a repair or exchange on their dime (everything new comes with a warrantee).
      My second thought is the same as my first.
      Third is to ship it back and shop locally for bike that works and can give you one-on-one help as time flies. Remember, even if it gets fixed today, it could have issues down the line.
      I would suspect the ECU or motor. If you have followed all the steps in this article as far as voltage and connection checking and it still won’t work, then once again, ECU or motor.
      Who you bought it from should offer help on-line or on the phone and ship you the parts they feel are bad.
      You say it is a week old. Did it work fine when you first got it?
      If needed, re-read both these articles—follow the checks the best you can—and get it working.
      I will try to be more help if needed—yet, get the company responsible to solve this.

      • SK says:

        The motor did sound a bit off at first (slight grinding) and it would come and go . The motor and all electrics would suddenly ; cut out at times also and I would have to charge it again for another couple of hours . This happened about three times before eventually the inevitable happened .

        I will definitely get the company to sort it out . One slight problem however . I have put on a new set of cranks, pedals, chainring, chain, saddle and seatpost . In fact on the first day the bike arrived I pretty much removed all the accessories it came with and put on the new parts . Whether I can find the original parts again could be an issue .

        Maybe I should just opt to get a new motor shipped out but again it could also be the ECU . Maybe if they take the bike back with the new parts taken off I can just pay the difference for the parts I have removed (won’t be much as they were cheap as hell hence why I swapped them out) .

        I have sent three emails . Two to the Ebay store where I purchased it and one to the company store . .No response but it is a weekend .

        One quick note . I also purchase an electric mtb from the store too . This is working perfectly after 3 months but it cost nearly twice as much so I guess you get what you pay for !!!

        Thanks for the advice dude .

  90. Rose says:

    Hello there, I found this quite by accident but I am in desperate need of help. I have owned a 48V, 500W Blue Stinger for the last 5 yrs, and I dearly love it. 2 yrs ago I started having issues as it didnt seem to be charging right and I seemed to have noise in the rear wheel. I put the bike away thinking it probably needed a new battery, but would wait will spring. Having purchased the new batteries last summer, installing and fully charging them, I had the same issue with back wheel. It’s like it seems to jump, if that makes sense. When the bike is on the rear kickstand, throttle all out, it spins great. However as soon as I weight bare at all, I can barely get more than 11 klm’s from the bike. I took it in this week to have all the batteries checked and completely recharged (making sure battery was still good), all is great. But I still have issues with the bike being sluggish, not going over 15 klm’s an hr. In Ontario Canada, our laws are the bike must be governed for max speed 32 klms, and until last year I’ve always been able to do that speed. A friend suggested possibly a rear wheel bearing, but I’m not sure. Would you have any advice, I would so much appreciate the help.

    Thanks ever so much in advance,

    • Rose, it does sound like the motor is in need of a repair, although most times a replacement is the way to go. From your description, maybe some of the internal sensors have failed or come out of place. There are also small senor wires coming out of the motor that could be damaged or experiencing a bad connection. I wouldn’t think the bearings are causing this, although if the wheel is hard to spin, maybe. If it were the bearings it would get much worse pretty quickly.
      There are people in the industry that could tear it down and inspect the inner workings, but I do think after some wiring checks, that a replacement is the correct start to your fix.
      You mentioned taking it in for the battery check, can they diagnose and fix your motor problem? Hope so, all the best of luck getting it back and running right.
      Let us know what it took, Turbo.

  91. mike says:

    Hey guys, maybe you guys can help me. I got this cheap from eBay. 1000 watt 48 volt speed controller. Never did work right, I think I burnt it out by hooking it up wrong (I got another speed controller from ebay but it has different colored wires and I don’t want to make the same mistake) Can any of you please help?

    • Mike, it seems you kind of answered your own question. Cheap stuff will always be cheap with no back-up support. You might try the Endless Sphere page (Facebook and an on-line forum) to see who can guide you to a good one. I like San Diego Electric Bike in Solana Beach, CA. They have the good stuff and all the answers. Good luck.

    • msjunk says:

      Can you post pictures of new controller wiring and any info from the manufacturer?

  92. shadsluiter says:

    I recently replaced the controller on my electronic bicycle (Fun8 motor with Lithium battery pack and a simple on/off throttle). What causes a controller to fail? Is it too much heat? Short in the system that cooks the electronics? Too much vibration from rough roads? Too much load on long hill climbs? Overcharging? etc?

    • On-off throttle? If is just a switch, that could cause problems. Several of your ideas could also cause ECU failures. It is important to make sure your entire system is compatible and matched.

      • hric says:

        So I think I’m having similar issues as a couple others. Battery is good but the bike doesn’t work. I lift the back wheel and it spins freely until I click the red switch on thottle to turn it on. It lights up and the motor comes to a quick stop, but frees up when turns off. Its an electric conversion kit with homemade batteries.

  93. Warren says:

    Hi, a friend of mine just bought a Cyclamatic power plus used and needs some parts, top of battery switch house w/a new key, his won’t turn anymore, and there is a wire off, and not sure where it goes. Need front and back fenders also. If anyone knows of a parts supplier It would be helpful. I’ve Googled it and can only come up with the battery tower as a whole for 300 in the UK, Thanks

    • msjunk says:

      Warren, You could look for an electric key lock at All Electronics or Fry’s or Radio Shack or similar place. I have pictures of a disassembled battery pack with wiring I could send you. I don’t see a way to post them here.

  94. hric, sounds to me like the controller is what is letting you down.

  95. SK says:

    Hi Turbo Bob . On my Ebike commuter (folding bike) I have the old style crank sensor which suscks because there is a 3second delay (sometimes 8 seconds) before the motor kicks in . The bike is nearly 26kg so as you can imagine acceleration is very slow as I have to pedal the weight before the motor kicks in and cycling in the very busy city that is dangerous (and annoys the drivers understandably) . What I have been doing is using the throttle and pedaling at the same time . I can get to 20mph in under 3 seconds . Once I reach my optimal speed and let go of the throttle and and keep pedalling until the motor kicks in again . I have been doing this for over a month now and so far no problems but I am concerned that this could damage the motor . I don’t see how as it’s technically the same as the motor kicking in from the sensors . I don’t want to damage the motor or the throttle or any other electrics doing this . I have however noticed some vibration coming from the motor now and then but it generally goes away . I think it’s the casing but not sure . Any advice would be appreciated dude .

    • SK, I think you have messaged me before—all about the same E-bike?
      It is fully ok to use the throttle to start the bike without causing any damage. That is what it is there for,

      • SK says:

        Ah yes it is the same Ebike . I got everything sorted from the manufacturer and got a new motor fitted as that was the cause of the fault . Unfortunately they claimed I did some damage to the paintwork or some rubbish like that and charged me full price for a new motor . Couldn’t be bothered to argue as guess what – that’s what happens when you use a bike it gets stone chips . Anyway thnks for the reply . Just to note I use the throttle and pedal at the same time because the sensor takes too long to kick when accelerating .

  96. Olivia says:

    Hello? How are you?
    I have Ezip-1000 scooter. But something problem. When i start scooter , it start but 30scond later it stop also the motor is very hot.
    It doesn’t work! So, I turned off a switch, than turned on again. It start again. But a few min later doesn’t work. Same problem. 😦 I thought that problem is controller. So ,
    I bougt new controller. But same. The motor is very hot.
    Could you tell me that what’s the problem?
    Should I buy a new motor?

    • Olivia says:

      Hi? This is Olivia. I tested it again. When I turned the throttle slowly it keeps working. However I turned the throttle maxmum power, 5scond later suddenly stop with the battery light red on. I turned off the switch again. The green light came back. The test results are the same. What is the problem? Please help me. Thank you let us know.

      • If the motor is getting hot—than it is the problem, or it is binding so it won’t turn easily. That is where I would turn my attention to get it working. It could be a brushed motor with worn out brushes—-or bad windings—or just binding too much.

  97. dusterjmb says:

    Hi Turbo Bob…I’ve just read through all the questions you have been posed with and looks like you’re the guy to ask. My boyfriend is wanting to purchase a used 2006 Mongoose CB24V450 for $250. Apparently everything runs great except the motor keeps running when stopped? The way he describes it is like the throttle doesn’t disengage. One of your replies to a post was regarding the motor cut-off safety brake switch. Is this an easy cheap fix or is this e-bike even worth it?

    • I wouldn’t suspect the motor cutoff-switches—but I would check the throttle first—and then maybe the ECU. Good luck.
      If the bike is in good shape except for this issue—go for it.

      • dusterjmb says:

        Thanks I went and looked at the bike myself after becoming an expert from reading your blog and it is the throttle…The pin isn’t holding. I had found a replacement part online so knew the cost and was able to get the bike for $200. So far it works good except for the throttle so we will be replacing that.

    • Richard Han says:

      Hi, i had also this problem, but had changed the throttle motor still running . any idea what pin you are mentioning ?

  98. Terry says:

    Hi everyone. I just bought a used e-bike. I don’t know the make or model, in fact i don’t have much details on the bike at this point.

    What I have discovered is that my bike does not have enough power to make it move. every light works, motor has sound, and charger charges from what I have noticed but wont move the bike. It has a broken throttle handle which very well may be the problem. When I turn the key it starts to move the bike forward without me moving the handle forward. It the instantly stops moving and wont move forward or back. the motor does work when i push the bike, but only works as good as a self propelled lawn mower. If I sit on the bike and try to get it to move it does not move at all.

    I’m about to take it apart but I’m unsure where to start looking for my problem. I think it’s a combination of a broken throttle and maybe a bad battery pack, but cant be sure. Does anyone have any suggestions for me. I would like to go the cheap route and buy the parts to fix this myself.

    Would anyone have any suggestions on what the problem sounds like, so I dont strip my bike down to nuts and bolts lol.

    Thank you 🙂

  99. Richard Han says:

    Hi Bob,

    I would like to share my E-bike problem. After I had changed battery from old to new (36v 12ah),
    the first ride was ok. But however the second ride was not ok. After a dismantle check, I found a blown fuse. I replaced it. Now the problem is, when I switch on the ignition, the motor runs nonstop. But when I press the brake from the motor, it blows off my fuse from the battery case, that I have changed three times. All wires I have checked and found all is ok. This bike was bought 3yrs ago. The ecu working since 2007.

    Will it be the motor as a problem or is the ecu a problem? I need your help.


    • Richard, it seems that his all started from the battery replacement. It sounds like you have checked all that fully, but try again. I guess the next step is the ECU. Double check all you do to make sure you have not cross wired something.
      Good luck, Turbo.

  100. arnie ess says:

    Hi Bob. My son bought me a Polaris Vector bike 2 1/2 years ago., for my 70th birthday. On a very irregular basis, the power will cut out. The battery meter on the battery and the one on the dashboard show the battery is fully charged. I’ve tried various methods to get it back working, and the one that seems to eventually work, is to turn off the power, pedal for 5-10 minutes, then turn the power back on. I might have to do this 2 or 3 times before it will start working. It doesn’t seem to matter the outdoor temperature. I’ve had no problem in 90 degree weather, and just recently i did have the problem on a 60 degree day, so i don’t think there is an overheating problem.

    I use the bike 6 months a year, and am out of the country 6 months. I acquired a programmable timer and was planning on setting it to charge the battery for 4 hours every 30 days. Do you think that this is adequate?

    • Arnie, I would guess your bike either has some connection problems—or a bad ECU. Best to have a local Polaris dealer check it out for you.
      I am not sure your battery solution is a good idea. Leaving the charger connected to the battery doesn’t fit into the normal way batteries are charged. There are battery experts that could answer this better—and next time I have the chance, I will ask one. If I were you I’d ask around—but don’t believe everything you hear.

  101. Hello everyone.
    My son owns a Beta minitrial electric 20′ bike.
    The issue we are facing is that when he “pushes” the bike a bit (ie) a steep hill, the bike suddenly stops. This means the motor stops but also the battery lights on the throttle also are going dark.
    When we switch the bike on and off with the key switch the throttle lights bilnk and some times they do nothing.
    If we leave the bike for some time it comes back to life for a while. This happens with the batteries fully charged and the lights when are lit seem to indicate the correct voltage. In deed if we keep using the bike it will last for the expected time.
    Does anyone has an idea?

    • Yup, you need to get it fixed. If for no other reason than for his safety. Sounds like a connection issue—-a thermal overload issue—-or a bad ECU.
      Get some help from the factory that makes them—or the shop you bought it from.

  102. Daniel Nelson says:

    Hi, when I switch the power on the battery pack before I even switch on the ignition, the wheel turns. The break cut off does not work. Also the throttle does not change speed as usual. This suddenly started happening and I even disconnected everything from the ECU except the battery and motor but the motor just keeps spinning. Would you be able to help?


  103. Jojo says:

    So I have had my Ebike for maybe about 4 months now. I ran into a problem earlier today and When I put the key in the bike turned on, but the speedometer ran right up to 60 with no power from the throttle given, and when i pulled back the throttle the bike wouldn’t even move. It didn’t even make any noise. I have no idea what would be causing this. Any suggestions?

    • Jojo, just roll that baby back to the shop you got it from. Any decent E-bike has a minimum of a one year warrantee. If you got it online the warrantee should still be good, you will just have to deal with it on the net with that comoany.
      Sounds like a ECU problem, but it needs more diagnosis before deciding. You didn’t give me anywhere near enough info to help you much more than this.
      Let us know what fixes it–or give me more info and maybe I can help you more.

  104. SK says:

    Hey Turbo Bob . Same bike again but this question is about removing a component . I want to remove the power adjusting switch from the ECU . Both of my Ebikes (haven’t mentioned my electric MTB to you before) have the same 3 switch power adjusting modules for pedal assist. If I unplug it from the ECU I lose about 20% power . Why is this ?!!! The simple answer is to leave it where it is and ignore it but I can’t . I want the bike to look clean and the switch is bulky as hell .

  105. Frank says:

    Hey..my problem is I only get 10 volts to my brushless. Motor..36 volts going. In??

  106. Mark says:

    Hi my sons 36v dirt bike was running absolute fine now when I turn the key on the bike revs itself and The motor goes on its own like the revs are jammed on what could be causing this

  107. frank marq says:

    My controller on my Izip won’t move motor. It has new batteries, 24volts. A new throttle, and a new controller. No power out of controller to throttle? 05 volts? Help?

    • Frank, sounds like you have just been replacing many items to see if they helped. If those new parts are working than the throttle output should be fine. If it has the external brushed motor, then I would check that next. Could be a worn set of brushes. That motor is easy to test, just apply the 24 volts DC straight to it. If it is a brushless motor than more checking will be needed.
      Let us know, Turbo.

  108. Martin Hicks says:

    Hi there, I was riding my bike to work. I have a rear drive electric bike, 250W ebike 36V10ah. The pedal started to slip then the pedal wouldn’t work any more. When I pedal forward the pedal, chain and cogs move but the rear tyre won’t spin. When I press the throttle the bike moves alot slower than normal, there is a battery drain and the motor gives off a burning smell. My bike is less than a month old and I’m very upset. When I pedal forward is like pedaling backwards, the tyre won’t spin

  109. Sure, it is no fun when you are having trouble with your bike. The fix couldn’t be easier though, just roll it down to the shop you got it from and they will fix it under warranty. Let us know how it works out.

  110. Angela Pulliam says:

    We bought a hyper electronic 18 inch bike. It’s not charging we have 2 fuse our question is are we to insert the fuses an if so , where do we place the fuses?

    • You know Angela, I am not familiar with that bike. Many E-bikes have a visible fuse holder on the battery case, some don’t. Usually if a fuse blows there are bigger problems. They do sometimes fail for no real reason.
      I suggest you check the voltage of the battery at the output (if it has some voltage the fuse is most likely ok)—and then check the voltage output of the charger.
      Many times the battery won’t charge because it is bad—or the voltage is so low it won’t trigger the charger to start,

  111. Nick Daigle says:

    Hi, my friend has an electric scooter. She charged the battery and the voltage indicator on the dash of the scooter says its got full voltage. But when she goes to accelerate, the voltage indicator drops to almost zero, and the scooter like lurches forward like go, stop, go, stop, go, stop. Could it be that her ECU is fried or something?

  112. Becky says:

    Hi Bob,

    I have a schwinn meridian, that I converted. I have a standard thumb throttle, just red power LED, Green and Yellow for power level, and a 36V v-power battery. I’ve only had this setup for about 6 months. On my way home tonight, it just cut out. When I freespin the front wheel, which is the brushless motor hub, I get the red power LED, but have no juice. My battery toggle switched broke recently, and it was stuck on so I just unplugged it to power off. If I get the light when I turn my wheel, there is obviously power. Please help!

    • If the green (full charge) light isn’t on—then a battery or connection problem might be happening. Also the ECU could cause such a problem too.
      If the green light is lit—then maybe a throttle or brake safety cut-out switch is acting up.

  113. Mark says:

    Hi,I have an E-bike with these specs
    • Rated power: 800W
    • Rated voltage: 60V
    • Front & rear tires: 10″ tube tires
    • Load capacity: 120 kgs. (max.)
    • Dimension: 1780*650*1080mm
    • Net Weight: 90 kgs
    • Brake type: Drum break
    • Battery: Sealed lead-acid
    • Recharge cycle: 400 times
    • Motor type: Brushless

    the problem is that when I charge it, it indicates full but when I use it the ebike runs very slow and the battery indicates empty(the light is good not dimming) and when i release the throttle the battery indicator goes back to full, when I charge it again it will charge for a second then it will show full charge on the charger. Please help…

    • Thoughts—-bad battery—bad connections in battery—-bad connections in main wiring harness. Use your voltmeter and continuity tester to see if the power is strong and getting to the ECU. Let me know what you find and we will go further if needed.
      Thanks for reading along.

    • Mark says:

      What do you mean by recycling? Should I change all the 5 batteries?

      • I am seeing now that you are using sealed lead acid batteries (I figured lithium—which really is the only way to go). These are easy to test for voltage and amp output. Only replace the bad ones (unless the others are pretty old) (they don’t cost much and don’t last too long).
        Make sure to recycle any batteries that are bad.

      • Mark says:

        Yup it is Sealed Rechargeable Lead Acid Battery , thanks for your replies, I’m thinking of replacing all the 5 batteries, is 2 years lifespan of the batteries long enough?

      • 2 years is a better than average life for sealed lead acid batteries. Please do make sure you recycle them (most likely with the firm you get the replacements from—or a car battery recycler).

      • Mark says:

        Thanks a lot

  114. Robert says:

    I got a kit for my E-bike (the hub motor/ tire combination, motor controller, lcd screen, etc) and bought a battery for it. It’s worked great for the past 6-9 months since I got the new battery for it. As I was riding to class today, I felt a sudden loss of power and got an error message on the LCD. I tried turning it off and turning it back on again, turned the throttle and heard a terrible grinding noise, had very low torque for a few seconds and then the error message came back and the motor stopped. I can pedal, and the wheel seems to move fine without the motor. After getting it back to my room, I turned it upside down and tried to run is slowly and the grinding noise is definitely coming from the hub motor itself.

    The bike motor I have is 1000w, 48v brushless. I bought it from an online DIY website that no longer seems to have it, so I have no idea who the manufacturer would be. I do have some mechanical experience (I’m a mechanical engineering student, although I don’t know much about brushless motors other than how they work).

    What should I do?

    • Robert, most likely one or more of the sensors have come loose inside the motor housing and that is what is causing your grinding noise. Some motors are easier to open than others, and fixing (probably replacing) the broken sensor can be fairly easy at that point. There are threads on the Endless Sphere forum page about it.
      There is also a chance the gears have broken or stripped, yet from your description I would think it is a sensor.
      If you can’t fix it, then replacing the motor would be the best way to go.
      Let us know what you find.

      • Robert says:

        Thank you for the speedy reply. When I opened it up, I noticed that part of the rows of magnets around the hub is actually touching, while the other side seems to have a gap. Is that normal? Is there anything I can do about that? It’s at an area where the wires lead to a computer board with 3 wires going from that (I’m assuming that those wires connect to the hall sensors?)

      • Could be excess heat damaged the glue that holds the magnets in place. Not sure if that could be corrected. Check it over close to see if that is the issue. It may be the damage is too great to fix and a replacement is the way to go.

      • Robert says:

        Alright, With the plate off, I plugged it an and tried running it slowely, it did seem like the magnets may have been grinding together, but that may have been from both of the plates being off and not holding it in place (I hope). I tested the hall sensors and I have 1 carrying a current but not the other two. Is it still worth trying to replace them in hopes that the plates being off is what’s causing the rubbing?

      • Fixing your own equipment is always satisfying if you can. Still, a fresh replacement might be quicker and better. Good luck.

  115. Fahad says:

    Hi, Really nice blog 🙂

    I bought a 250W geared hub motor with controller. I don’t have the throttle with it. So instead I have connected a Potentiometer to the controller. For testing I have only connected battery to the controller and Potentiometer as a throttle. Plus the motor is connected to the controller and I also connected the 6 hall sensor wires (according to color coding).

    When I switch it on, the motor starts turning at a constant low speed. If I vary the Potentiometer I can see its value on voltmeter. But the throttle doesn’t change. Around 2.5V on Potentiometer motor sometimes stops and changes it rotational direction.

    Can you help, what might be wrong.

    • Fahad—you may have gotten a reply at first meant for another reader—sorry.
      You need the correct throttle—that doesn’t cost much. Most throttles are double 5K pots that work opposite of each other. You need the correct one to make it work right and safe.
      Also, the color coding of the sensor wires is not necessarily correct for the connections. That could be another reason you are having issues. If you go on the Endless Sphere Forum page you should probably find some advice on how to find the correct way to hook them up—it can take some time. My friend Micah has a great section on this in his book.

  116. duke says:

    Guys, my hand throttle works but not my pedal assist. I have new ecbox and magnet sensor. I took off the brake sensors but no difference. Can you please help?

    • Duke, there isn’t near enough information here to be able to help you at this time. It sounds like you have a pretty good feel for your bike’s electronics though.
      Have you contacted the company that produced your E-bike?

  117. TypeRx says:

    Wow Turbo Bob — this is a great blog. So thanks in advance for the service you are providing the community.

    I have a Surface Element 604 e-bike I purchased just over a year ago. Recently when I was riding I went over a bump and I lost power. Basically, there is no power coming from the motor during pedal assist or with the throttle. In addition (and probably more important), there is no power to the main handle bar display panel which is where you select the “power setting”.

    Things I’ve checked:

    1. No clear breaks in the wiring, but I haven’t cut all wiring casing/sheath to check either. I have checked all din connectors and things are secure.
    2. Battery is fully charged and provides power to the rear tail light and battery meter when turned on. I have not checked voltage on it yet but assume it is not the problem. It slides into the controller. I checked the battery fuse (ceramic cylinder) and it has a 0 resistance, same as a brand new one.
    3. Shortly after purchasing the bike, I did cut and resolder all 8 wires going to the motor (I did it close to dropout where the motor wiring emerges from the hub) so that I could install a ring on the hub for a bike carrier. Those solder joints all appear okay, but it is a bit difficult for me to test continuity because they are mated to a din connector near the control unit. Let’s assume it is okay for now.

    So, since the display unit it not powering up is it right to think that:
    1. It is either the battery, controller, wiring from controller to display unit, or display unit itself?
    2. Even i f the wiring near the motor is severed, that shouldn’t impact the ability of the display unit to power up, right?
    3. Since this all started after going over a big bump, the most likely culprit is wiring/wiring connection, right?

    I’d like to bench test the display panel but only have a 12V battery handy (from a ride-on kid car). Since the battery is a 36V Lipo, will the display panel require a 36V power source to turn on? Basically, will my test with a 12V battery be a waste?

    You can find the manual for the bike at https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjFm7jgzYzLAhUEMGMKHb8JDf0QFggcMAA&url=http%3A%2F%2Fwww.pocketbikecanada.ca%2Fdownloads%2F2014-surface604-owners-manual.pdf&usg=AFQjCNHz0TCcuAbUFw3FHIB9nOsztDLaEA&sig2=fHKjVgz1Gfm6cIUQbKepVQ&bvm=bv.115091480,d.cGc — and the really crude wiring diagram is on page 21.


  118. Good pre-check over. Yes, a wire or connection has probably come loose—although it could be the circuit board in the controller. I wouldn’t’ use anything but the bike’s battery for the tests (although be extra careful not to short it). First, check voltage output from the battery. Then trace that into the controller. It might be best to contact the maker first anyway, they might have a idea of a common problem they have experienced.
    When you do contact them—-make sure to mention that Turbo Bob is still waiting to add a full review of their bike on my site.
    All the best of luck with this—let us know how the repair goes—and what it took to fix it.
    And, ask more questions if needed as the troubleshooting progresses.
    Thanks for the note, Turbo.

  119. Ryan says:

    My ebike wants to take off without me even pressing on the throttle. Would this be the ECU?

  120. Ryan says:

    Hi Bob, I have a 48v 1000w bike DIY bike. Recently the bike has begun taking off on its own without pressing on the throttle. I have noticed today that bike will only start doing this once I have tried to use the cruise control button. After hitting cruise the button blinks like it is constantly being disconnected. I have checked all the connections and they seem fine. Could this be the ECU or is it definitely the cruise control button itself?

    • Hi Ryan, sorry you had to write twice before I could answer, yet your second message gives me additional info that could help.
      Through the years the cruise control functions in the ECU have been found to be not the most consistent feature (the reason many E-bike makers don’t use it). They are included on many ECUs, yet you don’t see too many bikes with a cruise control button.
      Only a couple E-bikes I have tested have that feature working well—yet it is a feature I really like when working correctly.
      I guess you have a couple options—disconnect the button and enjoy the ride—or replace the ECU and hope for the best. Not much of an answer—yet it is the best I can do.
      Let us know your path and if it was successful.
      Thanks for reading along and asking for my help.

  121. fizzle0810 says:

    Hi Bob could you please help. I’ve got a 8fun 250w 36v hub, it only has the b.g.y wire. The controller im using is 36v 250w but it has also got a hall sensor plug as well. The problem is when I’m riding, it’s not moving to its potential then drops very quickly. Im also using 3x 12v 5ah cube batteries. I’m thinking it might be to do with that hall sensor plug, or the batteries, maybe throttle not sure. I’m new to all this and bulding a conversion from scratch. Any help would be greatly appreciated

  122. My first thought is the batteries. Not having the sensors connected really only affects most motors with a smooth start from a stop. If those are SLA (sealed lead acid) batteries then it is time to move to a quality lithium one—I think that should solve your issues.

    • fizzle0810 says:

      Thanks very much for your reply. yes it is the batteries wanted to make it as lite as possible but safer using lead cells. but now ive got from one extreme to another as its a prodject bike so now im building a lithium battery using 30x 18650 from used laptop batteries on the 3/10 bases. spent a week finding the decent onces from charging and disgarging mainly Sanyo got them on same voltage ect just waiting for my bms board to come now. will let you know if im legless or it worked by the end of next week lol
      Thanks again

  123. JULIEN mathieu says:

    Hello Bob !
    I got a Pedego electric bike recently. I have an issue I think with the motor. He won’t go to full speed..I already changed the controller but it doesn’t comes from there. My second guess is the motor in the rear wheel. Do you have a clue? I tried to contact the company but they don’t seem to have the answer. I really tried everything expect playing with the motor. That’s why my guess is that the problem comes from there. I wish to get in contact you a specialist. Thank you for your blog its great.

    • My thoughts go to the battery, controller setting, or connections. I wouldn’t suspect the motor on an issue like this.
      Plus, what are you expecting as a full speed number?
      A bad connection between the battery and controller will cause a heat issues that can be felt (by hand) or by looking for signs of overheating at the connectors.
      The battery should be voltage tested—and if possible, amp tested. This is where I would start.
      Some older Pedego E-bikes have a small adjustment pot on the wring harness that can be set to limit top speed. Newer ones have settings in the LCD display that can be altered.
      You don’t mention the year and model of the bike. Plus, Pedego is # 1 in customer service, so I expect they can help you, although doing it over the phone or by email contact is always a challenge.
      Let’s follow up with some more info from you on the exact problem, the tests you have made, and the progress, if any, that you have experienced as you try to sort this out.

      • MATHIEU JULIEN says:

        Thank you for those information.

        I know where to look!


        2016-04-29 18:45 GMT+02:00 Turbo Bobs Bicycle Blog :

        > Turbo Bob’s Bicycle Blog commented: “My thoughts go to the battery, > controller setting, or connections. I wouldn’t suspect the motor on an > issue like this. Plus, what are you expecting as a full speed number? A bad > connection between the battery and controller will cause a heat issues tha” >

  124. Brian says:

    I have a EMMO Ebike, I was riding along an it just quite, lost power, its fully charged, when I turn it on it trips my power braker, was wondering if you have any ideas of what it might be,?? TY

    • Hey Brian, I suggest rereading both of these posts (part 1 and 2). There are plenty of ideas there. If following the steps I’ve outlined doesn’t help, then give me some specific info—or take your bike to the local expert. Turbo.

  125. Syed says:

    Hi have Evora 200 watt folding bike just one month old, now my bike is not working some time its work and some time does not work i dont know whats wrong with that
    Please can u help me

    • Just zip it back to the dealer you got it from for the repair—bought it online? Not so easy then. It should still be under warrantee though. Contact the maker for the next step.
      If they are leaving you high and dry, then a good local E-bike shop might be able to help.
      Next up, if those avenues don’t pan out—-follow all the instructions I have outline in both articles. Check all the connectors and switches—use a VOM to check the brake switches and voltages at important parts. Outline all your findings and get back to me.
      I would suspect a bad connection somewhere. You can try disconnecting and reconnecting each plug, that can sometimes bring everything back to life.
      Good luck, Turbo.

  126. Greg Paarman says:

    I am hoping somebody can help me out on making a charger for a stock 2007 or 2008 Giant Suede electric bicycle. I suspect it has a 3 phase brushless motor? There is so little info. I can find on this. I purchased it in very nice used condition but the charger was missing. I have sent in submissions to Giant Bicycle co. and have yet to hear back, don’t know if the charger is still available or not? If anyone can help me out with the info. I need and how to build a charger (suspect I may need a 3 phase convertor) I would be greatful! Thanks, Greg P.

    • All you need is the correct charger that matches the battery voltage and type. It sounds like the battery might have gone bad from sitting so long. I suspect that bike uses SLA (sealed lead acid) batteries. If so, then the charger is pretty common for those older style E-bikes. Lithium battery chargers are much more specific.
      So step one is to determine what your battery is.

  127. David says:

    With out sitting on my bike it works fine but as soon as you sit on it and try to move it cuts out all lights LED panel everything can you help me with this problem please

  128. Interesting. Sounds like a connection problem, but hard to say for sure. I guess you need to do your voltage and continuity tests while someone is sitting on it, not easy, but possible.
    Let me know what you find as you follow though with the steps outlined in these two posts (while someone is sitting on your bike), Turbo.

  129. Denise tinkey says:

    Thank you. Excellent help! But how do you get the motor running?

  130. Akshay says:

    I have a Yo Smart, I don’t know what the is voltage and all, but it’s the motor, it is running, but running with jerks and noise, and also slower than earlier.
    So if you know what the trouble is please help me.

    • Sounds like a problem with the motor’s internal hall sensors—or maybe the connections to them. Try checking all the motor connections by un-plugging them–and the reconnecting them. Make sure they fit tightly. The controller is another item that can cause this. You might need some professional help to sort out your issues.

  131. D says:

    Where do I find a 24v charger for a 250w charger? Amazon or eBay do not have the one I need

    • There are many suppliers. Use the Endless Sphere pages (website forum or Facebook) to help guide you. A local E-bike shop is a good place to start.
      You will need more information though. I assume you mean a 24 volt charger for a 250 watt motor (bike). You need to be able to specify if it is for a lithium or SLA battery. The battery’s Ah or watthour rating needs to be known. Plus the plug style (and polarity) are important too.
      Did you lose your old one—or did it break? Most shops will want to see the bike to help determine which one you need—and to help assure themselves that the bike isn’t a stolen one.

  132. Murray Howkins says:

    Hi Turbo Bob,
    I appreciate your help and comments to so many of us.

    I have a 800W 36V rear brushless motor bike from a kit from LASHOP (probably a Chinese special). It worked great for nearly 2 years. However, over the last few months it has made a popping noise everytime I replugged the battery in. I unplug the battery everytime I lock it up so it gets plugged in about 2x per day. The battery is a 36V 20 AH battery from LUNA.

    A week ago, I went to plug the battery in and got a strong spark and some smoke, resulting in a blown fuse and so blackened wires beyond the fuse. The battery seems fine, but the bike is now hard to push, so I’m guessing it’s the motor. I didn’t put in another fuse to confirm – maybe to chicken that I might also hurt the battery. Would you do further diagnosis on this or just replace the wheel? I’m thinking that I should just go ahead and buy another kit as I noted in your above comments that it could be either the wheel or controller when this happens – Does my approach to this make sense or do I need to do further checking in hopes that there is a cheaper solution?


  133. Murray, I do my best. Hope I can help you.
    Chances are it is the controller behind all this. Most likely if you unplug the wheel’s harness, the motor will turn freely again. Some controllers are motor specific, yet many will be fine as a replacement. Probably the same supplier as the battery can help you out. Motors can be tested, yet there is no perfect way to do it, other than hooking them up right and giving it a go.
    The battery should still be ok, with whatever wiring repairs it might need.
    The sparking at the plug issue is common, yet just a small one, not big. A local shop has spark free switches they used to offer. It still sparks, yet in way you can’t see or hear.
    With any luck some TLC and a new controller will get you back on the bike path.

  134. John Blanchard says:

    Hi Turbo Bob,

    Awesome blog you have, answers are clear and helpful!

    So my question is; I have a 1000watt front hub motor from Hallomotor, it runs great with good power and acceleration. BUT I’ve noticed a bit of side to side play when I grab the tire and shake it. I think it’s the axle bearings. Is this hard to replace? Are they located on the motor covers and can they be tapped out?

    I’ve worked on many regular hubs and think this is the problem and before I pull it apart I am wondering how much work will be involved, like resplicing the power and hall connectors and maybe purchasing a gear puller. Any advice would be greatly appreciated.


    John Blanchard

    • Thanks John. Most all hub motors I have dealt with have sealed ball bearings, unlike the kind in most bike hubs and old style cranks. The 3 reasons you might be having issues are—bearings bad—-axle or hub (where the bearing is pressed into) are worn or opening up—-Something that is allowing excess endplay (axle or hub wear).
      They generally aren’t too hard to replace, yet you might find if the hub or axle is bad, that a motor replacement is the only way to go.
      The Endless Sphere forum has several threads that deal with hub bearings, you might get more insight there. Good luck with the fix. Turbo.

      • John Blanchard says:

        Hi Turbo Bob,

        Thanks for the quick reply! I hadn’t thought about the axle or hub because the motor is only three months old. I have contacted the manufacturer but since they are in China communication is somewhat limited.

        The bearings spin freely for a DD hub motor and is faster than an identical bike so it may be that axle :^[

        Best regards,

  135. Mark says:

    My rear wheel does not spin freely, it stops after about 3 seconds. My cones and spindle are well lubed. I’m no expert, but could it be a area inside the motor hub needs re-greasing? Please help.

  136. Rach gretton says:

    Hi, I have a Powabyke that I bought second hand about 18 months ago, it has up to now been brilliant, we put it in the shed for the winter and charged regularly, however since getting it out I cannot get it to run, bought new batteries and have lights on the dash but no power, no motor noise, pedals turn like a regular bike but gears are stuck on only 1st or 2nd but regardless of auto or pa I have nothing.
    We have no one local who knows anything about them and I am quite proficient at fixing electronics but this has me stumped. Please could some one advise me on what my next check is I’m unsure of the model it’s quite an old bike but has 5 gears possibly shopper, low step through…..any help would be much appreciated. Tia Rachell

  137. Dmunn says:

    Hello I have a veloteq commuter rsv it works great only thing is the throttle will pull right off and I have to manually turn back there isn’t any tension was wondering why that is and I think it’s a hall effect sensor Please let me know thanks

    • Sounds simple enough—replace the throttle with a exact replacement. Some older ones are different, yet most modern ones are a pair of 5k pots that work in the opposite direction of each other as you twist and un twist the throttle.
      Hopefully you can find a replacement from the company that fits and works like the original.

  138. Rach, I am not really familiar with that particular brand. Still, following all the testing steps I have outlined in my two articles would be the place to start. Something simple like the brake safety cut-off wires and switches could be the story. My articles may not tell the whole story—yet you need to make every check I’ve mentioned to do the trouble shooting. I will be glad to help more once you can tell me what you found as the steps are taken one by one.
    You mentioned something about your shifting—that is more of a mechanical issue and shouldn’t affect the motor assist system—-although needs to be addressed too.

    • Rach gretton says:

      Hi, thank you for your response, I have gone through the checks you have kindly written I did everything I could think of and every thing I could find while reading the check list but just cannot find a problem. I disconnected to cut off no change…..many thanks for trying to assist me, I’m beginning to think the tip is my only option……all the best Rachell

  139. I just purchased a ebike its supposed to do 20 mph and only does 12mph .the tech at manufacture wants me to take it to this battery place that exists where he is.I live in South Jersey and the one he said doesnt exists here.Does anyone know of a place to take an ebike battery and charger to be checked or even what i could buy to do it myself.Its only a 24 volt. Thanks

  140. Hi Bob, I am the one who just sent you the message about my battery. I am thankful I ran across your blog. I will be awaiting your reply, have a great night.
    And God Bless.

  141. Steven, if this is a brand new bike—problem solved, just return it to the maker for a replacement or refund. Even if you bought it online, it should be fully warrantied and they would be foolish not to honor your need to get what you paid for.
    Buying anything online is very risky—especially E-bikes. I hope they will take care of it (without you paying for any shipping).
    It isn’t up to you to fix your new E-bike—it is up to them.
    If possible, get a refund and go to a local E-bike shop and buy one in person from a reputable dealer–and get a bike you can test ride before the purchase.

    • Unforturely there is a no reture policy on this bike it was a scratch and dent.
      I am getting a new speedometer and took off the front wheel and replaced it with a new one. they sent me,It was damaged so the seller got the manufacture to replace it,I had to adjust it but it said 15 mph it might be faster i am not sure i am purchasing a better speedometer and check again i will let you know.Thanks

  142. docbolson says:

    Having some problems with a pedal sensor going out or not working. Is the voltage suppose to come out from both the red wire and blue signal wire. i’m getting a reading of 4.76 volts from the red wire coming from the controller and 4.52 volts from the blue signal wire as it exits from the controller. just wondering if the blue wire is suppose to have 0 volts coming from it?

  143. shane Hill says:

    I have an ecoped pulse white 48 V E-bike and now it wont charge. The red light doesnt come on, the charger stays green…so I took battery out and plugged charger directly into battery and same thing. I tried using a 24v charger from a smaller bike both ways and the same green light only. What could this be? the batteries aren’t that old…..can this type of bike only use ecoped chargers? and wont accept other chargers? I am stumped, please help

    • Shane, you should be making voltage tests on the battery and charger to help you find the issue. And what ever you do—don’t use a charger that isn’t the supplied one for your battery or bike.

      • Steven Connelly says:

        Hi. Turbo Bob My bike charger is getting warm is that normal. On Aug 23, 2016 4:02 PM, “Turbo Bobs Bicycle Blog” wrote:

        > Turbo Bob’s Bicycle Blog commented: “Shane, you should be making voltage > tests on the battery and charger to help you find the issue. And what ever > you do—don’t use a charger that isn’t the supplied one for your battery > or bike.” >

    • Hi Turbo Bob you replyed thinking. I am Shane my charger getting warm is this normal.And Shanes charger sounds like its bad ,mine is still charging i am purchasing a mutimeter waiting for it and will check mine,and the battery.

      • OK Steven and Shane, yes, the charger should get warm while it is doing its job. Some even have a fan inside to help keep them cooler. You can tell the battery is charged when the charger cools back to room temp (in addition to checking the lights).

  144. What you should be testing is for continuity in the sensor. Also make sure the magnet wheel is close enough to the sensor, lined up to the sensor—and has the correct side next to the sensor.
    Also, issues with the wiring, ECU or panel could cause problems.

  145. dave says:

    I was given a Raleigh select electric bike. The battery is good but the motor is not running when pedals are turned. It has no throttle, and everything is built into the rear (Sanyo cmu 2) back wheel. This bike does not use any sensor near the bottom bracket.
    Any ideas?

  146. I am not familiar with this particular E-bike. It is possible that all the sensing electronics are actually in the bottom bracket (like the old Sanyo E-bikes). That was a fairly complicated unit inside the BB to make it work (torque-sensed).
    If that can’t be diagnosed and fixed, possibly you can install another control unit that uses a throttle and (or) a crank senor (Hall sensor type).

    • I do hope you read both articles—tested the battery and connections—and tested the brake handle switches. It could be something simple—it quite often is.

      • starsky53 says:

        Hello Bob. All electronics are in the rear hub wheel.There is nothing in the bottom bracket and no brake sensor, the battery is good. We had the rear hub apart and can’t see any component damage. There is a coil of wire in the centre of the hub about 4″ in dia, and next to it a glass read switch. If I remove the centre metal spindle from within the coil of wire then the motor starts for about 3 secs and stops. Then if I switch off the power and move the metal spindle, the same happens again about 3 sec motor spin. If power is not turned off first, then there is no motor movement.

  147. Well Dave, that is a setup I haven’t seen—must be real old school. One thing with E-bikes, the companies really never posted any schematics and the such.
    You have two options that I see. Look far and wide for anybody that sold or worked on these that might have more info or spare parts.
    Or, move to a modern hub motor and external controller (with all that goes with it). The web and Ebay are filled with them—some good—some bad—some OK.
    If you had a local E-bike shop, they might be able to help you with all that.
    Most new motors come with the wheel already laced on, so doing it all yourself might not be too hard.

    • starsky53 says:

      Hello Bob….its very hard getting information on the internet for this bike,even raleigh who made the bike are very vague,whats made fault finding hard is that the electronics are encased in resin,at the end of the day if i cannot fix the bike,then as you say i will have to move on to something more up to date,i appreciate your help in your replies.

  148. Norma says:

    I hear a knocking somtimes while riding. Do you know what it coukd be.

    • Hi Norma. I am not sure if you are serious when asking me a question like that with no clue of the noise—bike type—or when it happens.
      Still, look for loose things—have someone ride next to you to try to determine where from the bike the noise is coming from—take you bike to a qualified mechanic—or turn up your music system,
      Hope that helps.

  149. JOSH says:

    I am having an issue with an Schwinn Izip. Brand new battery and charger. Charged for recommended time and put on the bike. I rode for about fifteen minutes, stopped got off and hopped back on when I turned the throttle nothing happened. I turned the off switch to off back on. And nothing please help.

  150. Hi Josh. Sounds like a possible bad connection. I suggest you read both articles through again—follow all the steps for the trouble shooting—and if that doesn’t help you find the problem—then tell me what you found with each step and them maybe I can help better.

  151. Kevin says:

    Hey Bob,
    I’m having and issue with my rig. LI battery 750w brushless motor. The bike runs great for a few miles and suddenly quits. The controller stays lit and reads full battery. I have an extra throttle that I tried, no dice. It seems as though the motor warms up and just quits (not hot to the touch). If I wait a while after shutting it off it will go again. Any ideas. I got the bike from here if it helps https://fattirebikeparts.com/index.php/xtreme-fat-tire-racing-bikes/fat-tire-e-bikes

  152. Steve says:

    The bike I have is supposed to do 20mph. I had it on the smoothest flat road, and as soon as it passes 17mph it went right back to it. I complained to the company. They should tell the truth what these bikes really do and not lie. I looked on youtube this guy got his bike over 20mph by turning it off while going down
    hill. He said with the ECU on it wouldnt do it.

  153. alexiofernandes says:

    Hi, I’m hoping you can help me.
    I have a 1000w 48v bike (drift trike).
    I soldered new connectors to the cables, just to make easy to change the wheel.
    Everything was working until I got caught by the rain. When I stopped I was able to turn on the bike but the motor was stuttering. Later I saw that 2 out of 3 cables from the battery was shorted out (for a while probably, the connectors where melted). Next day I soldered new connectors and everything works, but the bike doesn’t got even half the original top speed and acceleration. The motor doesn’t start when the bike is stopped, and only starts going (super slowly) after a kick start.
    Is the ecu broken? Is it the motor? what do you think?


  154. Hey Alex, sounds like a fun ride. It is mostly likely the ECU that has taken the damage. I would do a few checks on the battery to make sure that it wasn’t affected.
    There is a chance the motor took some of the problems, yet I would change the brain first and then go from there if it still has problems. Good luck getting it drifting again.

  155. Alfonso Avendano Mutis says:

    Hi Bob.

    Excellent Blog. I congratulate you.

    I buy:


    With this battery:

    The last time I use the bike. It was on a climb. It worked until it ran out of battery “Battery capacity indicator” (0) and “Half Twist Throttle” It did not send power to the engine.

    I charge the battery: Turning on the “LCD Control Panel” indicates the empty “Battery Capacity Indicator”: empty, zero.
    However: In the “LCD Control Panel” Display 3. VOL = 54.6
    If possible can I upload an image from the LCD?

    I have performed the battery charge several times and the “Battery Capacity Indicator” is empty or at zero as if the charge had not been performed. Never charge the battery for the computer “LCD Control Panel”. With the battery level at zero it does not allow to drive the motor. Can not be used. The engine is not energized when the “Twist Throttle” is pressed. There is some way to restart so you can read the voltage and the computer “LCD Control Panel”, realizes that the battery is charged. I have loaded the bottle several times and I can not find a solution.

    Is there any way that the “LCD Control Panel” be aware that the battery is charged?

    Additional Information:
    The last time I use the bike. It was on a climb. It worked until it ran out of battery “Battery capacity indicator” (0) and “Half Twist Throttle” It did not send power to the engine. It appears that the “LCD Control Panel” is in this state and does not read the new battery charge so that “Battery capacity indicator” is set to full or all bars or (four bars). For this reason, it is possible that with a reset or return to factory values, the “LCD Control Panel” is forced to read the new capacity of the battery.

    Thanks for your help.

    Alfonso Avendano Mutis.

    • Sorry for the delay. I would think by now you have contacted the kit maker for their thoughts on your problem. I didn’t read that you did any voltage checks on the battery with a VOM. Could be a battery issue. If not than the ECU or the link between that and the display would be suspect. You have added a bunch of info, yet not enough to clue me to the exact problem.

  156. bob says:

    Why does my E-bike alarm keep going off?

  157. I often wonder the same thing Bob——oh wait, I don’t think my E-bike has a alarm.
    I doubt more info will allow me to help you out, but maybe. I am sure you have asked this question to the maker already.

  158. Robert G. says:

    Bob, I need your help. I built my 83 yr old mom a tricycle with a 48v1000w front wheel up motor from Amazon (for $650), Its the hub motor with the brushed aluminum circular lines on it and it has a 3 light 48v thump throttle. Now, the problem is that not matter how long the batteries are charged. The light guage only goes to orange and not green. I checked the individual lead acid batteries and they are charged at a range of 11.76v to 11.96v I also checked the connector from the battery that connects to the ECU and it shows an average 46.76v combined. I am at a loss as to why the motor isn’t getting full power or the gauge light going to green. The wheel does run. But when it does the light goes down to red. I hope you have some ideas.

    • Robert, the real truth is that a quality lithium battery costs less in the long run, performs better in every way, is lighter, will outlast SLA batteries by 3-4 times, won’t leak (some do), and doesn’t need to recharged immediately after every use,
      A 12 volt SLA should read a minimum of 12.7 volts after a charge—usually even more.
      Almost without a doubt it will come back fully to life with 4 new 12 volt SLA batteries. That is the less expensive way to go for now. Make sure all the interconnecting wires are clean and tight. Also the main battery wires to the system. Also make sure to charge fully after every use—and I am wondering about your charger. It should be a smart charger that tells you when a charge is done—-not just leaving in on for long times and not knowing what the status is.
      Upgrading to lithium is really the smart way to go. With many systems all you need is a quality battery with the correct smart charger. With some you may need to upgrade the ECU (controller). This is something the motor kit supplier should be able to help you with.
      Make sure you get a quality battery with a quality BMS (battery management system), there are many out there that are shaky and dangerous.
      Let us know what it takes to make it work right again, Turbo.

      • Robert Grant says:

        Bob, do you have any links to a quality Lithium 48v 1000w battery provider and a charger? I’m thinking the charger is wonkey too.

  159. Jim says:

    Hi have a Bafang BBS02 kit on my Stumpjumper. It’s worked great for over two years and 4300 km. However, recently the pedal-assist stopped working – it’s as if it does not detect that I’m turning the pedals. It’s not the brake cutoff because I can still use the throttle (if I apply a brake while using the throttle, it cuts the throttle automatically).

    So I’m perplexed how to go about debugging this – I suspect that the PAS detector is inside the motor housing (but I’m not sure).

    Any clues?

    Thanks !


  160. Most likely the electrics in the motor. Lectric Cycles in Las Vegas are the experts and can get it all back on track for you.

  161. SebK says:

    Hey man . I just bought a new Ebike . The dashboard and everything works fine but the motor doesn’t . It has pedal assist and a throttle . It is 36V battery and 350W motor . I have checked all connections and everything is connected fine . I have removed the brake levers and built in light and horn but on my other two Ebikes this didn’t cause a problem . Pls help . Thank you .

  162. [2017.01.16] Excellent webpages!

    I have quick question: 1000w 48v rear wheel motor (7 wire, 3 thick, 3 thin, and an earth), 11.8Ah lithium ion battery, when cycling hard the motor cuts with a clonk/bump and the display flashes the whole battery symbol, after a second or so it works again, the battery segment restored, the interval between these “events” decreases as the battery discharges and occurs with decreasing pedal effort. Is it simply the battery is not suited for such a meaty motor?

    There is no evidence of any problems with the operation of the motors mechanicals however the battery charge indicator never seems to drop otherwise.

    KT-LCD1 display:

    Your learned counsel most appreciated!

    Dr B

  163. Kevin says:

    How r u bob. Anyway I can get a number to call u to get sum help to wire my 1000watt escooter speed controller. I unplugged it n now it’s not powering back up. Don’t know y

    • Hey Kevin. The best way to contact me is through my Facebook page (same name as my bike blog). Chances are I am not the one you need. I would call one of the big E-bike shops or companies—or the people you got the controller from.
      I have some wiring diagrams—but not all by any means. I am surprised yours didn’t come with a diagram explaining which wires are which. Try the Endless Sphere Facebook page or web forum. There is plenty of info there—and probably the exact person who has your answers.
      Hope you get it figured out, Turbo.

  164. Michael says:

    I have a e bike voyger that has been used three times I fully charged my battery put it on and it reads battery not charged on the handle bar controls any answers please

  165. Michael—follow the steps in the posts to see where you voltage problem is. Once you have the results then you might be able to figure it out—or I can help.

  166. Carlos says:

    great article!
    I purchased a Chinese kit. 48v 1000w brush less they said. When riding, I press on the led control low, high , medium , 6km and so on, nothing happens always pushes to the same speed no change.

    is that normal , expected? thx!

    • Tom says:

      Fyi, The LED Control Panel Speed Setting Low, Medium, & High and 6km is for Pedal Assistance feature only does not support or change the speed of Thumb/Twist Throttle.

  167. Carlos—no where near enough info to answer your question. Follow each step of both articles and get back to me with your results,

  168. Willem says:

    Hi Bob, Hope you can offer me some advice. I have purchased a kit which I installed on old MTB frame. It has an LCD display and turn throttle. Everything seems to be working fine when on the stand. The rear wheel spin up to max speed (30 Km/h). The cutoffs on the brake levers are working correctly.
    The problem is when I take the bike off the stand, and climb on it, the motor kicks in for a second or 2 when I turn the throttle and then stops for a few seconds before it kicks in again. It continuous this cycle for as long as the throttle is kept open. The display and everything else tend to work fine. Battery indication is good.
    Can this be a bad connection or is it a controller problem?
    The motor is rated as 250W and the controller as 36V/20A. It is a Lithium pack battery fully changed.

    • I would generally blame an old or poor working battery for this—but that would be on a motor with 1000 watts or more (heavy draw). Still—a bad connection could be an issue.
      Other things to consider are the in motor sensors and the way they are hooked to the controller—or the controller itself.
      Something like this can be hard to diagnosis. I would contact the supplier and see if they can decide what parts to substitute first to fix the problem.
      Good luck.

  169. Victor Debray says:

    Hello there! Need a professional opinion on my situation. I’ve been using a 48v aliexpress kit with a 52v 30A battery for about 6 months till I fried the controller while riding in heavy rain. Decided to take things to the next level and got a 2kw sine wave controller as a replacement. Although I definitely got more torque and the motor is completely silent now, I have to be super careful with the throttle. Any sharp twist and the motor cuts out. Turning the ignition off/on doesn’t help, I have to reconnect the battery to make it run it again. I was expecting the BMS to self-regulate the maximum output current instead of cutting out completely.. Was I wrong? Should I get a better battery?
    Original kit: https://www.aliexpress.com/item/Passion-Ebike-48V-1500W-Bicicleta-Electric-Bicycle-Bike-conversion-kit-Rear-wheel-motor-kit/32476876343.html
    New controller: https://www.aliexpress.com/item/48V-2000W-18-mosfet-motor-brushless-sinusoidal-wave-controller-for-electric-bike-hub-motor-quiet-controller/32607633369.html

  170. Hi Bob, Hope you can offer me some advice. I have purchased a second hand electric bicycle.it has some issues. From the controller it works with only indicator, gear, starter, charger and power to 24 v. motor which rotates the chain. Everything seems to be working while the battery is old and need a long time to charge. The wiring was little bit different then it should be. After only few rides the controller got damaged and the motor as well as wheel keeps running. As a result I bought new controller. With this i ride only one day. After that the wire again burned.
    Now I wired all with new thick wire. After that The display and everything else tend to work fine. Battery indication is good. But motor is not running.
    Can this be a bad connection or is it a controller problem?
    The motor is rated as 250W and the controller as 36V/20A. battery 12 v.

    • Sounds like a mess—and that the wiring still isn’t right. And….you could have damaged the controller again.

    • John Blanchard says:

      Hi Mr. Hasan,
      Not to step on Mr. Turbo Bob’s message, but I had an experience with burned out wires and a shorted controller. My fix was to replace the controller, wires and the hall sensors. The hall sensors for me was on a hub motor. If that is what you have, you’ll need to carefully open up the motor and replace them. There are many excellent instructions online, but it will require you to be able to solder carefully and epoxy the tiny sensors back into place. Also you will need basic bike repair tools to open up the hub, the magnets are quite strong and can seriously injure your hands and fingers if you accidentally allow it to snap the cover closed.

      There is a method to testing the sensors with a voltmeter to check if they put out a voltage (about five volts) when the wheel is rotated. But it sounds like they have fried. The motor may turn with manual input, be careful to not hurt yourself when it engages. But, the motor will run rough and not have much power if it does. The hall sensors help with the timing of the power for smooth running.

      Good luck!

  171. Jay says:

    Hi I have a problem with my new Yorker e-bike, I was riding one day when all of a sudden the battery gauge that’s powered by led lights just suddenly turned off, now in the past this had happened to me before when I unknowingly kicked the key to the ignition with the back of my heel which completely turned the bike off, I realized the bike was off because the led lights to the energy gauge weren’t on, after realizing what just happened I quickly turned the key back on and on I went. But this time was different because after noticing the lights were no longer on, the bike was still on and not off, this happened this happened a few days ago and I’ve been riding this bike like this since.The bike ride perfectly fine I just can no longer know how much battery life I have. Would you happen know what the problem might be!?

  172. Right off hand, no idea. I would take a close look at all the wiring though.

  173. Douglas Bush says:

    I have a Ancheer E-bike. The motors assists when I pedal, but I get no response from the throttle.The 4 wires from the throttle are black, blue, red, and brown. I get ~11K Ohms between black and red, and between blue and red, and ~28K between black and blue. No change when I twist the throttle. I’d appreciate any advice.

  174. saad says:

    hello, please i just bought a second hand e-bike , but i have a weird problem, when i put my battery to charge even overnight , a i got only 20% of the battery that is charged. do someone have any explanation ?? thank you very much

  175. Ian Cullinan says:

    Dear turbo , I recently purchased and fitted
    a 48 volt 1000 watt conversation kit by Voilmart. I have paired it to a Samsung 48v 20 amp battery. Bike works well except for when. I open throttle to full it triggers something. Which cuts power off , so I have to stop . If I then turn battery power of/on again power is restored again . Until I open throttle up again . Any thoughts on this will be appreciated

    • Sorry not to get back to you sooner. By now I would think you contacted the supplier—got everything fixed—and are enjoying the E-bike world.
      Hope so.
      And to let you know—the kit is trying to get more volts or amps than your 1000 watt motor needs. It seems you need a more powerful battery.

  176. Robbert Vandendorpe says:


    This post is really old, but still. I’d like to mention that you helped me a lot. I had a front brushless motor that would only chug the wheel forwards and backwards and then nothing everytime the throttle is turned. By disconnecting the motor (with battery power on the controller) it somehow got solved. So the reset tip was pretty useful for me. I guess the motor must have been overheated at some point in a heavy hill climb.

    So thanks!

  177. Deb Turnbull says:

    HUGE THANKS – I checked brake cut outs -OK. Checked throttle – OK but connecting the battery and disconnecting the motor cable for a few minutes worked a treat. One very grateful e-biker.

  178. lgf says:

    Hi Turbo,

    Im brand new to E-bikes, and I just purchased a great little bike from someone. It was working perfectly until I rode up a hill… The battery and everything cut out and stopped working. I opened the battery case (the bike seems to be a custom built bike with two 250W 40V batteries. There was no smell of burning or any smoke. *The indicator showing the batteries charge was on full before the hill. After taking off the connections to the battery and putting them back on the bike still would not work, the indicator showing the battery charge was not showing anything and no electrics were working.

    However at certain times when trying to turn the bike on the battery indicator would flash on full and then would dim down and turn to off in a split second.

    I tried to charge the batteries when I got home, but even after several hours it is still in the same situation.

    *I would note that when the bike is being charged and plugged in to the wall the bike works perfectly (all electrics, lights, and throttle all working) So it makes me think there is something happening with the batteries either now not keeping charge or perhaps knocked themselves off for safety on the hill incline but I don’t know how to get them back to working order. The batteries are fairly new (2 months) and not been overly used at all.

    Thank you so much for any advice and help!

  179. Sounds like a bad battery or two—-but most likely bad connections in the battery box.

  180. Liam G says:

    Hi I bought a Carerra Vulcan E about a year ago from the works “cycle to work” scheme. I had an issue with it about 8 months ago where the chain came off and pulled the wires out of the PAS PCB on the front crank. I have soldered them back into place but the bike gives me no power to the motor since.
    The wiring is done correctly because I had chance to check it with a friends. When the wires Came out the screen showed ERR 50 & ERR 34.
    The screen and battery all light up and the manual boost button gives me a tiny kick up to 3kmh.
    Is there any way I could fix this issue by buying a new pcb?
    If so does anyone know where I can buy Carerra parts (or this pcb) from? I checked in Halfords (checked the warranty but apparently it wasn’t covered for accidental damage, which wasn’t caused by a fault) if they couldn’t get the part for me and they couldn’t.
    If I can’t find a replacement PCB, can I wire the system up differently to have a different way of powering the motor, and what would be the best option to do this.

    Thanks for allowing me to pick your brains,

  181. Marc says:

    Hi! First of all thanks for just reading this, if you could help then awesome!!

    I have a ebike kit with a brushless motor of 36V and 350W. The controller is a 6 MOSFET one with LCD screen. I had an electronic problem with the battery and I opened the controller to check if that was it, and a spark happened. Since then the controller does not work properly. The output lines for the brakes, pas and throttle is not 5V, but the screen does turn on and operates normally. I have checked the electronics inside and one resistor heats up a lot when the screen is on but the bike is not working at all. Also the voltages in the internal voltage regulator for the 5V are too low. I tested the MOSFETS and they are fine, so my guess is that something somewhere is shorted, but I can’t figure out what.

    I know that this a solutions is almost impossible to know for sure with this info, but I will be very grateful if you could give me some suggestions that I can try, cause I am out of ideas.

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