Determination of SOC of a Battery Pack Used in Pure Electric Vehicles

Thevenin´s model having a RC network characterizing the battery polarization is used for SOC determination. Reverse current method is proposed to decrease the polarization elimination time. And the polarization voltage of the battery model is identified using the nonlinear least square technique. A maximum available capacity based SOC determination method considering the SOC limit of each cell for battery pack in series is presented in the paper. Discussed results demonstrate the efficacy of the proposed parameter identification technique and the SOC determination method for PEV application.