A method to monitor valve-regulated lead acid cells

The individual electrode impedance parameters and internal resistance of industrial type 120-Ah valve-regulated lead acid (VRLA) cells are obtained from a galvanostatic nondestructive technique. The resistive components of the cells are found to be minimum at a state-of-charge (SOC) value of 0.5. The study reflects that the optimum performance of the VRLA cells is achieved at SOC values between 0.2 and 0.8.