Internal Resistance as Termination Indicator during Lead-acid Battery Formation
Lead-acid batteries are a reliable, inexpensive energy storage technology used extensively in a wide range of applications. Before selling this technology to customers however, manufacturers must subject the batteries to a time- and energy-intensive charge known as formation. As more capacity is charged into the batteries during formation, more capacity will be available for discharge by the customer. Since the output per unit input has diminishing returns, knowing when best to terminate a formation is of economic importance to manufacturers. In this study, internal battery resistance is introduced as a novel termination indicator. Resistance trends are first measured during a series of laboratory-based formations. The trends are then correlated with formation completeness such that a manufacturer would be able to identify a suitable termination point based on these non-invasive in situ measurements. The method is partially verified for large-scale battery production through additional experimentation in a lead-acid battery manufacturing facility.