Enhancing battery lifespan : estimation of Lithium-ion cells with « quasi-flat » voltage chemistry

Abstract

Our research focuses on SOC estimation for LiFePO4 batteries, known for their flat OCV profile across SOC values—a vital BMS parameter. We design two sliding mode observers, one emphasizing battery voltage error convergence and the other OCV estimate accuracy. Simulations initially used constant parameters and were later validated with real values accounting for current, temperature, and SOC variations. This work contributes to advancements in LFP batteries SOC estimation, enhancing BMS performance.