Advanced cell balancing strategies for scalable lithium-ion battery management in electric vehicles

Abstract

The growing demand for efficient and reliable energy storage in electric vehicles has led to significant advancements in battery management systems (BMS), particularly in cell balancing. While existing research has primarily focused on balancing techniques using a small number of cells (typically 2 to 4), or lead-acid batteries, and employed algorithms like Kalman filters and state of charge (SoC)-based estimations for passive resistor-based or simple inductor/capacitor-based balancing, these approaches often face limitations in energy efficiency and scalability. In contrast, this study presents a comprehensive analysis of 13 lithium-ion cells using both passive and active balancing, as well as an advanced active staggered cell balancing strategy. The proposed system reallocates the charge more efficiently among cells, minimizing thermal loss and improving overall energy utilization. Using MATLAB®/Simulink® simulations, we evaluate and compare the simultaneous start and staggered start methods under various load conditions. Results show that active balancing methods can reduce energy loss from 15–25 W (typical in passive systems) to 3–7 W and decrease balancing time from 120–180 minutes to 45–80 minutes. Notably, the staggered start method delivers superior thermal management and extended battery life, confirming its suitability for high-performance and scalable BMS in electric vehicles.