E-Bike won't start (sometimes) - any help?

Hello,

I have a problem with my bike. Sometimes, it just doesn't start (by start, I mean I turn on the switch and try to move).

It's very hard to pinpoint the exact cause since it's happening randomly.

For example, I took my bike this morning to commute to work (12kms) and everything was fine. Sunny, nothing out of the ordinary. When I tried use it at midday, I turned on the switch and then tried to move but nothing happened.

This is happening every few weeks, (if not months) where my bike doesn't start for no reasons and it's getting very annoying. Normally, what I would do is to plug it 30 sec, turn on the switch then try to move. It would work every time. I would unplug the bike then ride it like nothing happened. This sucked since it means I needed to to bring my charger every day at work. On the other hand, it was a solution. One time, when I didn't have my charger, I got on the bike, gave it some speed (like you would do with a car) with my feet and then it started.

However today, I tried all this and it didn't budge. Not really sure what to do or what the problem is. Going back by walk with a 220lbs bike for 12 kms is not my idea of fun.

TLDR; How can my bike starts flawlessly for months/weeks...until it doesn't...without any apparent reason? If it would be something broken, I guess it would happen often and not once every few weeks. I went to my shop and they didn't know what it was since the bike was working fine when I brought it.

Thanks for the help

No it does not. If I open the switch while the bike is still on the stand and turn the throttle, the wheel will spin. I don't need to pedal or anything. It works the same way a scooter would.

I though at some point it would be a throttle problem (ex; a connection problem) but that fact that it would work when I plugged it made me think it could not be that.

Now that plugging it in doesn't solve it anymore, I don't know what to think.

Battery on/off switch or key switch ?

Make sure all pins are seated in the connectors and not backed out. May be a loose bms sense wire givjng bms a false reading and shutting off. Turning back on when you plug in the charger. What kit and battery we talking about. By pass the on/off switch.

Step 1: Check all connectors and connections.
Step 2: Make sure your battery is balanced and charged.
Step 3: Make sure your ebrake is not cutting power.
Step 4: Test your throttle
After that we start thinking about the controller.

I'd look hard at all the wire and plugs on the bike, 90% of the time intermittent problems are that.

But what you describe, sounds like the loose connection might be inside the battery. Putting the battery back on charge just briefly is re setting your bms, which may have turned off for some reason.

BUT,, this may be entirely wrong. you may just have a loose wire on the bike, that usually gets jiggled somehow in the process of putting it on the charger.

Did you forget to put gas in it and your on the wrong forum?

what did I win?

It sounds like a loose connection or bad wire. When the bike is working ok take a voltmeter and take power reading through wires leading up to and past connection and control and component points. It is a slow process, but to find intermittent problems can be a real pain. After you take the readings, you will need to carry your volt with you at all times. Harbor Freight sells a decent volt meter for a about $8, time to time they do give out coupons for a volt meter for free with any purchase. Vibration is a big problem with E-bikes, things have a way of working loose and wires insulation rubbing through. As a final note take some water with you wherever you go because if you do break down and have to pedal you can get deh B i u Quote Code List List= [*] Img URL Font colour pre spoiler= strike youtube
ydrated in a short time.

What controller do you have?

I had a similar problem. Sometimes all would be good then I'd hop on my bike and it would not work. After noticing one day that when I was not giving my bike any throttle the motor wanted to turn I figured it out. My controller (Kelly KDS48100E) has a programmable setting that prevents the motor from starting if there is throttle applied when the power is turned on. My throttle was not always going to zero so my motor would not start until the throttle had zeroed. I unchecked the setting in the programming and have not had the problem since. As long as I hold a brake lever in at stop signs I'm not making my motor work trying to move a stationary bike.

Try holding the throttle on and then turning on the battery, if it spins then you don't have the protective setting that I have.

Try removing potential problems one at a time. I used a 36V dewalt battery to eliminate my battery as the issue. it's probably not a good idea to connect directly to your charger as your bike likely pulls more current than your charger will allow, you could end up cooking your charger.

This was just happening to my bike yesterday. My display with light up shows full Voltage I apply throttle and nothing happened. I found a backed out wire on the ignition the two red wires you touch together with the off on switch. It was able to lighten show the display but I don't know why the ignition wire would stop the flow to the motor. I mean it showed 80 volts on my display but with just not kick over my motor the pin had backed out of the plug and I just put a new pin in and made sure it was seated. Need to go down after lunch and do a test as it was intermittent yesterday. A ghostly problem for sure.

Thanks for the replies.

I realised that plugging the bike in was not what made it work. What made it work was turning the switch on/off (which happened before and after I plugged/unplugged the bike).

Last week, when my bike didn't want to work, I turned it on/off 4-5X times out of frustration and and it worked. So I guess that is probably a wire problem.

I did about 100 kms since then and I had no problems at all.

How can I know if there is something loose between the switch and whatever is connected to? is it something I can do by myself?

Thanks

alghul said:

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How can I know if there is something loose between the switch and whatever is connected to? is it something I can do by myself? Thanks

Click to expand...

Depends on your switch and if you can fix it.
Are you any good with electronics?
Is it wiring to the switch or inside the switch?

Also, show us some pictures. Keep them at 640x480 for easy posting. Make sure they in good focus.

What does your switch look like? What does the wiring look like?

I just found my brake cutoff switch have moved (as the screw was lose)and was cutting off the throttle as every thing was working. P.s. i don't know it cuts off throttle as I didn't test throttle just replaced. When I disconnect the brake plug did it work. Playing with this problem for 3 days. Good luck with the ghost.