Electric bike shuts down when going up hill.

Discussion in 'Maintenance and Repairs' started by LenaBru, Oct 10, 2016.

  1. LenaBru

    LenaBru New Member

    I have an electric bike with a 36v Battery.

    A month ago there was a problem with my bicycle, it stopped sending power to the motor, periodically.
    I took it to the bike shop and they decided to replace the controller.
    Ever since they replaced the controller, the bike started shutting down when going up hill (even though the battery is completely charged), when I was able to climb that hill on the bike with no problem before.
    The bike shuts down immediately, not going even 10 meters when starting up the hill.

    The bike shop refuses to believe the new controller is the problem, and tells me the problem is my battery.
    The coincidence of the two events makes me believe this is not true.

    However, the battery marker on the control pad does go down to the end when i am going up that hill, when before the controller was changed, it would only go 2 points down (there are 6 points on the control pad)

    How can I be sure what the problem is ?

    The battery is 1 year old.

    Along with the controller they also replaced the throttle, which I barely used.
    I disconnected the throttle, the problem persists.

    The bike storage is as follows:
    I ride it 5 kms a day , and it is either in my house or in the office, never in the sun.

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  3. Berry78

    Berry78 Active Member

    Can the shop put on a loaner battery to try?

    I'm wondering if the new controller is programmed wrong to limit the motor's output. IE, keeping the motor to a max output, and if it goes above that, to cut it off. Maybe this is a setting that can be changed.
  4. LenaBru

    LenaBru New Member

    The shop refuses to give me a test run battery without my buying it.
    I live in israel, and the law here says that the bike cannot go above 25 kmph. and thus the original controller whenever i'd go near 25kmph would cut off the power, but would not turn off the battery.

    This one seems to behave in a similar fashion, however, when i climb up the hill i go at 14-18 kmph, not any where near 25...
  5. Berry78

    Berry78 Active Member

  6. Ann M.

    Ann M. Administrator

    Perhaps you could take a different tack with the shop, @LenaBru, and use your battery on one of their known good bikes that has a similar setup as yours. If it is the battery, the same issue should persist. I'm very sorry to hear that this shop is not a bit more cooperative and willing to test the system. Can you leave it with them to test ride; maybe be persistent with the manager for some help--you did pay for a replacement controller and you still have a problem with the bike.
  7. JayVee

    JayVee Well-Known Member

    Lena, the bad faith of your shop seems obvious to me. Try to appeal to their sense of fairness and better business practices if possible.

    Otherwise it's time for plan B.

    Some suggestions:

    - Tell the shop you will complain to consumer organizations if they don't take you more seriously. File the complaint if necessary. Invoke the fact that repairs come with a warranty (if applicable under the laws of your country).

    - If it's a "big brand", write to the e-bike manufacturer to complain that you aren't receiving quality service. This usually works pretty well.

    - Go back to the shop with someone else (brother, sister, boyfriend) in order to talk to them. It's sounds like they're trying to take advantage of you. An external influence might tip things in your favor.

    - As a last resort, take legal action.
    Ann M. likes this.
  8. harryS

    harryS Active Member

    Swapping the battery onto a similar bike that accepts it would be the clear test. If you have any electrically knowledgeable friends, another approach is to put a voltmeter on the battery terminals and watch the voltage on that hill. A bad battery will drop below 30 volts (assuming you have a 36 volt battery).

    Then again, that is what your display is telling you. The voltage is dropping below the minimum voltage when you lose all the bars/points.

    Did they put the wrong controller on an ebike? Well, if you put a 48v controller on, and use a 36 V battery, it will work for a little while, because a freshly charged 36V battery that uses 18650 lithium cells will be 42 volts, and the 48 volt controller will run until the battery drops under 40 volts. However, I don't think you would see six bars/points at the start.
  9. Easymotion

    Easymotion New Member

    Hi there I have a 2013 ebike bought it new in 2015 been riding it up until a month ago and started cutting out it went back the factory had new motor and reset the torque and controller. Got it back and blow me after 16 miles it does the same thing again. Informed the supplier he now has ordered a new controller so in the mean time I waiting and still ride it and put up with the cutting out as I stop for about 30sec. Then turn power back on and off I go till it stops again. Hopping and waiting for phone call to take it in.
  10. adirsp

    adirsp New Member

    Did you ever fix this problem?? - what was the solution in the end - I have the exact same issue - uphill the electricity just cuts out - I turn the switch on it works for a few more meters and then does the same - (only uphill)
  11. indianajo

    indianajo Member

    Voltmeter tells the tale. I had a bad battery 11 miles after I bought it, going to 6 v when the controller dropped out, but the second battery I bought worked for 60 miles before the controller started shutting down. Voltmeter on the charge terminals says the battery is fine, 48 v. A bad crimp or solder joint on the load terminals can also cause low voltage, feel for heat at the connection after shutdown or skin the insulation off the wire after connection temporarily to get the aligator clip on the feed wires to the controller. Controllers are supposed to shut off if the battery gets too close to minimum voltage - 40 on a "48 v" batttery. Since my controller is doing this hard after 60 miles with a 48 v battery reading, I suppose I've either blown the controller or shorted a turn in the motor. Works great with the bike upside down - no load. Next thing is to put an amp clamp on the motor phase wires to detect a shorted turn, but I can't figure out how to read it while riding, or load the motor without me on the bike. A reading greater than 26.5 amps AC on any phase wire would indicate my $210 power wheel is shorted internally. It it winter & I left the converted bike out at the summer camp, so the testing will have to happen next spring. Annying thing was, even though I was going ~25 mph when the controller started shutting off, neither motor shell , controller shell, or wire crimp was hot. I suspect the heat sinking in the $22 controller was not done properly go make the heat flow out to the shell, but geared wheel motors for $210 don't have a good reputation either. Fortunately with a geared motor, when you have a total failure you can ride home without the motor dragging you down - they have an internal one way clutch. Was 26 mile to pedal to support the first time, 9 miles the second time.
    Last edited: Nov 19, 2017
  12. Scooteretti

    Scooteretti Member


    From experience if the bike works OK on flat terrain (minimal load) I would start with load testing the battery. A good electric bike shop (MUST) have a proper load tester to test the overall health of the battery and see whether it's performing correctly. Most decent load testing equipment will be able to print of a report where you can see a profile on the battery and determine exactly what's going on. If you can't find an ebike shop with such equipment try and industrial battery shop who specializes in lithium ion batteries.

    Very disappointing to hear that they were not able to help you out. Keep us posted on how you make out.


    Last edited: Nov 20, 2017