Corrosion resistant positive grids, novel separators, and negative plate additives for increased VRLA battery life

Valve-regulated batteries suffer several problems not seen in wet batteries. They have a relatively shorter life compared to wet batteries, although the information from the ALABC programs has shown how to significantly extend life. VRLA batteries suffer somewhat reduced capacity compared to flooded batteries although the specific energy may be higher. VRLA batteries are much more difficult to charge correctly and the charging practices generally have to be modified during the life of the battery because of changes within the grids, active material, amount and composition of the electrolyte, as well as the electrochemical potentials of the plates. There are three major problems with VRLA batteries which cause them to fail prematurely. These are the sudden loss of capacity, gradual loss of capacity, and the inability to recharge the negative plate. These conditions have been deemed premature capacity loss by the ALABC. This paper deals with the problems of sealed VRLA batteries and how the ALABC program research results have flowed into battery materials to improve the life and performance of VRLA batteries.