Determination of state of charge of lead-acid battery by EIS

The paper explores state of charge (SoC) determination of lead-acid battery cell by electrochemical impedance spectroscopy (EIS) method. Lead-acid cell was explored during intermittent discharge and intermittent charge. Nyquist diagram, open circuit voltage, Z-modulus and the phase angle of the cell for frequencies 853 Hz, 5.37 Hz and 351 mHz were used for the state of charge determination.