A review of equalization topologies for lithium-ion battery packs

Battery equalization technology is a key technique in the research of electrochemical energy storage system. It balances the state of charge (SOC) of cells in series-connected battery packs using the power electronic converters to improve the life of battery packs significantly. In this paper, the equalization approaches for series-connected lithium-ion batteries are classifying existing circuits into dissipative ones and non-dissipative ones. Analysis of the cost of equalization circuit, the equalization effect and the difficulties of modularization are presented. Advantages and disadvantages of each approach are given to provide references for research direction in future.