Bafang BBS02 750W switching off intermittently

[hsors]

It started when I was riding at full speed (24A current) by a very hot day (35°C) after the bike was left a full day under the sun. I switched off and on and the bike started again. I thought it was a temperature sensor that did cut the current because of excess heat. But after the bike/motor/controller cooled down, the motor is still intermittently switching off even if I do not draw a lot of current (although the switch-off is almost instant when I draw max current).
Any idea on how to fix this ?
Thanks much !

 

[dustNbone]

Is the display turning off? If so it's most likely a battery issue.

 

[hsors]

Yes, the display is turning off.
Your thought is that if it was the motor controller that would switch-off the motor, the display would remain on because the motor controller has no mean of turning off the display, right ?
Thanks much.

 

[dustNbone]

Just from personal experience, when the Bafang controller hits low voltage, it just cuts power to the motor, the display stays on. It will try again a second later if you're still engaging the throttle (or PAS I suppose).

If the battery cuts power it turns everything off, and requires the load to be disconnected and reconnected before it will try again.

So we know it's most likely the battery, time to figure out what the problem is. What type of battery is it?

 

[hsors]

Yes, it's most likely the battery which is I bought on AliExpress: https://www.aliexpress.com/item/48v...560.html?spm=a2g0s.9042311.0.0.3bba4c4d0BI5GU.
Not sure it's easy to find the defective part on such a battery...
Thanks