Modern commuter scooters (Ninebot Max G2, Xiaomi 4 Ultra, Vsett 10+) are moving toward . The BMS talks to the controller via a serial data line. If the BMS registers that the cells have been disconnected (voltage drops to zero), it permanently locks itself into "Error 21" or "Dead Battery Mode."
Enter the controversial world of .
Just remember: Lithium respects no one. Measure twice. Weld once. And always, always triple-check those balance leads. Scooter Repacks