METHOD AND DEVICE FOR ESTIMATING STATE OF CHARGE OF A BATTERY

According to a method of estimating a state of charge of a battery (110), a present voltage value Vt(k) and a present current value IL(k) are generated by detecting the voltage and current of the battery. A reference open-circuit voltage value VOC,ref(k) is determined based on a state-of-charge estimation value SOC(k). First to third parameter values α1(k), α2(k), and α3(k) are estimated by using recursive least squares (RLS), from the present voltage value Vt(k), the reference open-circuit voltage value VOC,ref(k), the present current value IL(k), and a previous current value IL(k-1). A next state-of-charge estimation value SOC(k+1) of the battery is determined by using an extended Kalman filter (EKF), from the state-of-charge estimation value SOC(k), the present voltage value Vt(k), the reference open-circuit voltage value VOC,ref(k), the present current value IL(k), the previous current value IL(k-1), and the first to third parameter values α1(k), α2(k), and α3(k).