ebike motor stops working

[karlclayton0509]

I have laced a 36v 350w gearless hub motor in the rear of my Sun Cruiser Fat Bike and when I twist the throttle it jitters and then goes. After riding up the street, if I stop it and try to start again it jitters longer and starts again. After a few stops and starts the jitter becomes continuous and the only way to get it to run again is to leave it to cool down. I am using a 36v 14ah frog battery.

Any ideas why it works for only 5 minutes. It won't get me anywhere of use.

When I learn the controller with the learn leads connected it didn't spin until I twist the throttle. When I release and twisted the throttle again it slows the wheel down and you can hear something going on but no reverse motion or resistance on the wheel. Repeat this turns the wheel on forward and then no motion. Is that normal and is it learning correctly?

 

[mikebikerad]

This sounds like a faulty motor controller or a bad "sensorless motor controller" with a poorly designed smooth start feature. You mentioned that you are using a frog style battery, which is usually only something we see on the low cost conversion kits. I would start by checking all connections, than I would contact the group you purchased from as usually problems with lower cost kits are not isolated events.

Good luck!

 

[karlclayton0509]

I am changing the connectors so there are no wiring issues. I have discovered that you must listen to the motor to make sure you are not over throttling so the motor has time to catch up with the controller. It is a very fine balance to get the right sweet spot to get it moving. Sometimes it just cuts out all together and I have to turn the key off and on again for it to respond.

 

[TheThirdWheel]

If you're running a sensored controller+motor combo, the problem sounds like either defective hall sensors, the wiring configuration for them is incorrect, or there's a bad connection somewhere.

After buying a cheap conversion kit via eBay, it was nothing but trouble. The motor would need to be spun by hand/pedalling before it would start spinning when the throttle was applied, and when it did finally go it would shudder back and forth pretty violently while riding. It turned out to be a very poor connection in the hall sensor plug. After making sure all the metal pins inside had a snug connection, I zip-tied the plug closed and it's been performing flawlessly ever since!

 

[dogman dan]

Sounds to me like a hall sensor or hall plug connection issue. The controller learns, but still runs shitty on two phases. if it runs at all.

 

[999zip999]

Look to see if the pins in hall sensor plug havn't backed out. You can adjust the locks on the pins with a razsor blade just a little to lock. If works, I hot glue the back of the plug.