A new state of charge estimation algorithm for lead acid battery

This paper presents a new algorithm for state of charge (SOC) estimation of lead acid battery. SOC estimation is important for all batteries which are used for energy storage. The precise SOC estimation prevents a battery from discharging and overcharging. The proposed SOC estimation employs an extended voltmeter method for finding SOC. The proposed method can be implemented by an algorithm and it requires information about battery terminal voltage, current, capacity and datasheet. By considering the changes in battery terminal voltage and current the SOC can be determined. The magnitude of current discharge causes varying rates of change in terminal voltage and SOC. This SOC estimation algorithm for lead acid battery has been developed and verified through MATLAB/Simulink. By comparing drawbacks of various SOC estimation methods with the proposed method, it is understood that the proposed method provides the precise SOC estimation and it is highly efficient.