If it is a battery pack that has just been assembled, please measure the voltage of each seires cell from the cable. And Check whether the cable connection sequence is wrong or not ,also check each the individual cables connection quality to see if there is any wires disconnected or not . .
If the abnormality occurs after using for a period of time, check whether there is loose screw (the cable is crimped or screwed), or the connection between the cable and the protection board connector is loose or not.
The battery has activated the low voltage protection , and please Connect the charger to supply power to the battery and it can recover to normal status.
In condition of the battery assembly was finished with full charged status , or when the battery is fully charged, any hand touch on the BMS which could resulted in wrong activation of discharge protection with the BMS, also Some of the protection boards can not release the discharge protection when load off . You need to connect the charger (without voltage detection function) to recover the discharge normally .
When the B-/C- wire is soldered, the paste flux damaged the control circuit of the protection board which causes the protection board work abnormally.
Check whether the fuse, any wires, etc. or the discharge circuit is open or not
Some protection boards temperature protection function with discharge ,please check if the temperature detection probe damaged or not which would result in discharge failure .
Some of the protection board has a low-temperature protection function. If the ambient temperature is lower than the discharge low-temperature protection value, it cannot be discharged.
Some protection boards have a high-temperature protection function. If the ambient temperature is higher than the high-temperature protection value of discharge, it can not be discharged also.
Some of PCB has the switch function , when the switch is disconnected, , damaged,or the switch wire is broken or dropped, which may cause discharge abnormally.
Battery can be discharge normally with the electronic load, but can not drive the motor of vehicles . It may be that the battery charges the controller capacitor with a large current instantaneously, which activated the short protection with the BMS . Generally, re-installation of the battery on the vehicle once or disconnected the battery once, this problems can be solved like that way . The occurrence of such problems is related to the internal resistance of the cell, the size of the controller capacitor, and the capacitive load capacity of the protection board. It can be solved by increasing the load capacity of the protection board to address such problems.
