Regrouping strategy of retired batteries considering SOC consistency

Abstract

This paper proposes a method for retired batteries based on SOC consistency matching. This method takes the SOC consistency of the battery pack as the standard, which calculates the model parameter matching relationship to optimize the performance of the pack. Based on Thevenin equivalent circuit model, the mathematical model of lithium ion battery is established and the model is parameterized. Additionally, a battery pack reconfiguration criterion based on SOC consistency is proposed to reveal the mapping relationship between cell parameters and battery pack SOC consistency. Finally, the battery parameters are identified by the recursive least squares (RLS) algorithm to select two groups of batteries. Dynamic and constant current tests are performed on battery packs with different topologies, which are used to verify the feasibility of the proposed method. The experimental results show that the proposed reorganization scheme can better ensure the consistency of the SOC of the battery pack during charging and discharging.

Keywords

• Retired batteries
• SOC consistency
• Battery regrouping
• Reconfiguration criterion