The cells in the battery are affected by materials,production process,and the environmental temperature,during the using period,and their voltage unbalance may occur.The problem gradually increasing that will make the battery overcharge and the overdischarge damage leading to the battery pack can't work normally.The technology of transfering battery equalization introduced.It can completely solve the problem from the external battery that the voltage imbalance in the battery seriously affecting the battery service life.The technology using the active balancing technology makes the voltage difference between the adjacent batteries minimum.The technology research project has been proved by practice.