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.

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88 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.
      Turbo.

  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

      • 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.
        Turbo.

      • 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.
        Turbo.

  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.

    Thanks

    Rob

    • 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.
      Turbo.

      • 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.
        Turbo.

  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:

    Hello
    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.

    Thoughts?

    • 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?
        Turbo.

  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

  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.
      Turbo.

  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.
    Thanks.

    • 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.
      Turbo.

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