Motor cuts out after start up

[cycling weakly]

I have a Tongsheng motor powered by a Woosh 36v 15ah battery. When I turn on the display everything looks OK. I wait for the Spanner symbol to disappear the motor pulls away fine, but only for a short distance. Maybe 100 metres or so, the display goes blank & no power. I stop & turn back on & everything works fine. Previously I had the same battery powering a BBS02 500w, it would sometimes do the same thing with that, but not every time. Once restarted neither motor has cut out again. Any thoughts on a cause?

Yours. Baffled of Burnley.

 

[Woosh]

try rebalancing your battery, it may help. Flatten it as much as you can, then when charging, leave the charger connected for a couple of hours after its LED goes green.

 

[Deleted member 4366]

I have a Tongsheng motor powered by a Woosh 36v 15ah battery. When I turn on the display everything looks OK. I wait for the Spanner symbol to disappear the motor pulls away fine, but only for a short distance. Maybe 100 metres or so, the display goes blank & no power. I stop & turn back on & everything works fine. Previously I had the same battery powering a BBS02 500w, it would sometimes do the same thing with that, but not every time. Once restarted neither motor has cut out again. Any thoughts on a cause?

Yours. Baffled of Burnley.

Bad connection?
Faulty soldering on the key switch?
Faulty solder joint anywhere else?

 

[cycling weakly]

Why would it only cut out once & then behave itself for the rest of the ride?

Steve

 

[Electric Bike Rider]

Why would it only cut out once & then behave itself for the rest of the ride?

Steve

Could be a bad cell (or paralleled group, unsure of your config).
I run 16s 1p and if one cell was bad or out of balance and undercharged then it would hit the cell LVC first and the BMS would switch off the whole pack to protect it.

Or could be a bad connection where heat expands things and caused it to connect again, this would be dangerous though and if the case be careful where you keep and charge your battery.

If it is the battery, both motors experienced the same issue so sounds likely, then you might have to take it apart.
You could possibly test it by seeing if it goes further if you just eek the power on carefully with low throttle. It could be a cell that is worn out and sags heavily under load and hits the cell lvc despite being fully balanced.

 

[arrkaye]

I had the same issue with the BBSHD.

Problem was bad connection between the battery and the cradle. Movement and heat generation while riding caused an already tenuous connection to break.

After i chiselled away some of the melted plastic in the cradle, the problem went away.