Energy crisis and environmental pollution are a serious threat to human survival and sustainable development. To alleviate the energy crisis and maintain the living environment of mankind, people develop and utilize new energy sources such as solar energy and wind energy. In order to ensure the safe and reliable use of the battery, and improve the performance of the battery after group, the battery management system has become the key technology of the wind energy storage battery system and the electric vehicle power battery system. Battery balance management is the core technology of battery management system and the focus of the current research. Combined with this background, this paper focuses on battery equalizer and equilibrium strategy. The research strategy is to transfer the equilibrium energy directly from the high voltage single cell in the battery pack to the ground voltage cell.