Qualitative Characterization of Lead–Acid Batteries Fabricated Using Different Technological Procedures: An EIS Approach

Electrochemical impedance spectroscopy techniques were applied in this work to nine industrially fabricated lead–acid battery prototypes, which were divided into three type/technology packages. Frequency-dependent impedance changes were interpreted during successive charge/discharge cycles in two distinct stages: (1) immediately after fabrication and (2) after a controlled aging procedure to 50% depth of discharge following industrial standards. To investigate their state of health behavior vs. electrical response, three methods were employed, namely, the Q-Q0 total charge analysis, the decay values of the constant-phase element in the equivalent Randles circuits, and the resonance frequency of the circuit. A direct correlation was found for the prediction of the best-performing batteries in each package, thus allowing for a qualitative analysis that was capable of providing the decay of the batteries’ states of health. We found which parameters were directly connected with their lifetime performance in both stages and, as a consequence, which type/technology battery prototype displayed the best performance. Based on this methodology, industrial producers can further establish the quality of novel batteries in terms of performance vs. lifespan, allowing them to validate the novel technological innovations implemented in the current prototypes.