Research on equalization control method of equal charge series battery modules for SOH enhancement

The inconsistency of the available capacity of each unit in the series battery module leads to a decrease in the available capacity and a decline in the health status of the battery module. Therefore, this paper proposes an equal capacity series battery module balancing control strategy for SOH improvement. The method takes the consistency of the remaining charge of each unit in the series battery module as the balancing objective, and the coefficient of variation of the remaining charge of each unit in the series battery module as the balancing control parameter. Through charge transfer, the remaining charge of each unit in the series battery module tends to be consistent. Design a series battery module charging and discharging test to simulate the process of equal charge balance control. The test results show that the remaining charge of each battery in the balanced module tends to be consistent, and the SOC values of each individual cell tend to converge with increasing charging and discharging time. Compared with the unbalanced battery module, the battery health status is improved by 12.9%. The proposed equal charge balance control method can effectively improve the capacity utilization efficiency of series battery modules and enhance the health status of batteries.