Effect of ageing on the impedance of the lead-acid battery

•Values of the impedance components are changing with ageing of the cell.•Impedance modulus and phase angle are changing during discharging.•Impedance modulus and phase angle are changing during charging.•Used frequency reveals different impedance components of the battery. The paper deals with the influence of ageing on the cell impedance parameters during discharging and charging of the lead acid cell. Z-modulus and phase angle of lead acid cell were measured for frequencies from 2570 Hz to 0.351 Hz. The results are based on the electrochemical impedance spectroscopy data. Impedance measurements during discharging and charging were performed on a new cell and on an aged cell before and after 100% DOD (depth of discharge) cycling. Accelerated ageing was performed by repeated deep discharge to 0.0 V. The results of impedance measurements on a lead-acid battery cell show that cell ageing associated with degradation mechanisms has a significant effect on impedance parameters. Measurement of the Z-modulus and the phase angle can be an indicator of degradation processes in the cell during ageing.