BBS01 turns off on load

I have a BBS01 350W unit.
I returned mine to China (Alibaba I admit ) to repair the controller. After many problems I got it back, no life in it at all. Perth Electric Bikes in Fremantle traced it to the C961 display so I upgraded to the C965. Now can get it to fire up but the moment any load is put on the whole system shuts down.I need to turn the battery off, then on again before I can get it to start again.
I suspected the connection between the battery and unit but even directly connected by physically joining the wires same result.
Any ideas? Anything appreciated
Thanks

I wonder what battery are you using?

Battery not charged or battery not balanced due to sitting around waiting for stuff to come back from vendor, so battery's BMS shuts pack down.

Leave battery on charger for a few days then retry.


Alternately, controller to motor phase or hall wires are connected wrong, see:
https://endless-sphere.com/w/index.php/Determining_the_Wiring_for_a_Brushless_Motor


Alternately controller is now set for higher current draw than battery can handle, so battery's BMS shuts pack down.

I'm having a similar problem with my BBS02. I suspect my battery pack is on its way out - it's been charged almost every day for 16 months now. Seems fine when just off the charger but 6km later it occasionally powers off when I hit the throttle - power off/on and it's fine again. Using PAS I never have the issue, but then power draw is much less. A new battery called for I think.

Ade, I had exactly the same thing - new battery fixed it. I went LiFePo4 to get a flatter discharge curve - cheaper for me than going for a big aH battery at the time. I discharge mine at 1.85C max throttle.

Thanks everyone for the info, has given me a direction on what to check out. Also been given some ideas from a member privately.
Will give you the result when I've finished.
Thanks again

Sometimes the phase wires get their insulation cut where they pass inside the motor's casting. The edge on the hole is really sharp. The unit fails after it gets warm as the wires move slightly. It trips the BMS inside the battery.

Myself and a fellow builder are often having to open them and put insulating tape around the thick phase wires because of this. The silicon insulation is easily cut by the motor case inside.

Problem solved! Took the whole unit down to Perth Electric Bikes and after a good check they discovered the battery wasn't producing full power even though it appeared full and was reading over 41 volts. Tried a replacement battery and all well.
Thanks to all who gave ideas and help esp Tatt.
Now I want to get more out of it!!

Did you keep the old battery? With the help of this forum you should be able to salvage and reuse major parts within. Most of the cells will be fine.