Kalman filter based state-of-charge estimation for lithium-ion batteries in hybrid electric vehicles using pulse charging

The battery is one of the most important energy storage components in EV/HEV. Failing to estimate the state of the charge accurately will bring the risk of overcharge or over discharge. The traditional Coulomb counting method will bring accumulated error over time, therefore high deviation occurs between the estimated and real state of charge. Different estimation strategies are compared in this paper, i.e., Coulomb counting method, open-circuit-voltage method and Kalman filter based state of charge estimation. Experimental results validate the effectiveness of Kalman filter during the on-line application.