Model based SOC estimation for high-power Li-ion battery packs used on FCHVS

A model based method which recruited the extended Kalman filter (EKF) to estimate the full state of charge (SOC) of Li-ion battery was proposed. The underlying dynamic behavior of the cell pack was described based on an equivalent circuit comprising of two capacitors and three resistors. Measurements in two tests were applied to compare the SOC estimated by model based EKF estimation with the SOC calculated by coulomb counting. Results have shown that the proposed method is able to perform a good estimation of the SOC of battery packs. Moreover, a corresponding battery management systems (BMS) including software and hardware based on this method was designed.