Effect of soaking time on the positive active material and performance of the valve regulated lead/acid battery

During valve regulated lead/acid (VRLA) battery production bottlenecks occurring on the production line can result in varying delays between the different stages of production thus acting as a source of inconsistencies between batches. This paper describes a study conducted to determine the effects of different soaking times between the ‘acid fill’ and ‘formation’ stages of production. X-ray diffraction (XRD), BET surface area analysis, scanning electron microscopy (SEM) and electrical testing have been used to study the compositional and morphological aspects of the positive active material just prior and after formation. Results indicate that paste compositions are effected by the time period between acid fill and formation. However, electrical test results and SEM examination of formed pastes suggest that soaking time is unlikely to affect the resulting battery performance.