Effect of absorptive glass mat soaking method on electrical properties of VRLA batteries

Abstract

The valve-regulated lead-acid (VRLA) battery with an absorbent glass mat has an important part in the global market for chemical power sources. This type of cell is used for both automotive SLI applications and stationary energy storage. The absorptive glass mat (AGM) is a key component in the VRLA battery, which co-determines the electrical properties of the system. For this type of lead-acid battery one of the most important stages of its production is the process of filling the cells with electrolyte and soaking absorptive glass mat before formation. Due to glass mat properties and overall high compression of plate group, this stage of production is difficult to carry out properly, especially in a short period of time. Therefore, to reduce the time, vacuum fillers are used. However, the problems of homogeneous filling of the glass mats cause that the process is often carried out in two steps. This article presents the effect of different electrolyte filling techniques on the 12V VRLA AGM battery's properties. Chemical and electrochemical experiments showed that the implementation of the one-step electrolyte filling process did not cause a decrease in the battery performance, while also reducing the time by about 26.7% compared to the method used previously.