Model-Based State-of-Charge Estimation for a Valve-Regulated Lead-Acid Battery

State-Of-Charge (SOC) estimation for Valve-Regulated Lead-Acid (VRLA) battery is complicated by the switched linear nature of the underlying dynamics. A first principles nonlinear model is simplified to provide two switched linear models and linearized to produce charge, discharge, and averaged models. Luenberger and switched SOC estimators are developed based on these models and propogated using experimental data. The results show that estimation errors are halved by including switching in the observer design.