An Efficient Passive Cell Balancing Approach for Lithium-Ion Batteries

Abstract: Lithium-ion batteries find wide applications in electric vehicles, energy storage systems, and portable electronic devices due to their high energy density and long cycle life. In a series-connected battery pack, divergence in individual cell characteristics can lead to SOC imbalance, which severely degrades performance, safety, and cycle life. Thus, cell balancing emerges as one of the essential tasks of the BMS. This paper deals with the modeling and simulation of an efficient passive cell balancing method using MATLAB Simulink. The proposed scheme is applied on a ten-cell series-connected lithium-ion battery pack, and balancing is triggered by a threshold-based switching action. The simulation results show that the proposed method causes significant reduction in SOC imbalance and attains equilibration within some finite balancing time. Because of the simplicity and low cost of the method, it is suitable for low-to-medium-power applications in batteries..

Keywords: Lithium-ion Battery, Passive Balancing, Battery Management System, MATLAB Simulink, Cell Equalization, State of Charge (SoC)