Why does power off once starts the motor of the vehicle ?


A. Unplug the battery from the vehicle and charge it with a charger. If charging is possible, then measure whether the output voltage from the BMS is equal to the total voltage of the battery. If they are equal, remove the resistance to increase the over-current protection value of the BMS B. Whether the B- cable is thick enough and not long and thin. If the B- wire is too long and thin, the first series group cell can easily suffered over-discharge protection problems

C. Whether the connection wire or nickle strip is thick enough or not .it should not be too long and thin between these series connection cells otherwise the undervoltage protection will be easily happend.

D. When B- and C- port were connected with screws.the contact resistance becomes bigger once the screws are loosened,even the static output voltage is normal, but there maybe no output or the output voltage is low under loading process, whats wrosen the screw connection position will be heated seriously .

E. Poor consistency of the cells or weak welding quality with some cells which will reuslt resulting in low capacity of any one series cell; and imbalance problems of the battery pack was seriously , when there is any one seires cell with much lower voltage than other series cells . the undervoltage protection can be easily occured when battery was loaded with large current .

F. The starting current of the direct-drive motor power tool is relatively large. if the battery can be discharge when the battery pack is connected to an electronic loader, how ever once the power tool was started ,power cut-off happend in this situation . It is necessary to increase the discharge overcurrent protection value of the protection board or increase the discharge overcurrent protection delay time .

G. when battery can be discharged normally connecting to the electronic loader ,however power cut-off problems happend once starts the motor of vehicle.

it maybe the short circuit portection occured when battery connects to the contoller of the vehicle ,the battery can charge the capacitor of the controller with instant large current ,when faces this kind of problems , normally , it will be turn to normal by disconnecting the battery once with the vehicle and then mounted to the vehicle again .
This kind of problem is related to the internal resistance of the cell, the size of the controller’s capacitance, and the capacitive load carrying capacity of the protection board. It can be solved by increasing the capacitive load capacity of the protection board.