State of Charge Estimation of Lithium ion Battery Based on a New Linear Online Model

State-of-charge (SOC) estimation is a very important part of battery management system. Many estimation methods are based on nonlinear models, which makes the operation more difficult. In this paper, a new linear online modeling method is proposed and SOC estimation of lithium ion battery is realized. The experimental results show that the method has a good estimation effect. In addition, compared with the SOC estimation of extended Kalman filter based on the first-order RC model, this method requires less computation and has a stronger anti-current interference ability.