Effect of compression on the behaviour of lead-acid batteries

Mechanical pressure applied to the plate group is known to increase the cycle life of lead-acid batteries. However, the mechanism of the active material stabilisation process is not completely understood yet. The evolution of mechanical pressure in a lead-acid battery during a cycle and through cycle life is also a topic with still many open questions. Additionally, the separation systems available today are not able to exert high compression on the electrode plates: glass mats crush when compressed too much and the gel design does not allow any significant pressure generation at all. Daramic have developed the new acid jellying separator (AJS) allowing the application of mechanical pressure on the plate group. This paper reports on 1. The capacity evolution during cycling for cells with different separation systems namely AGM, gel and AJS, under a variety of initial compression levels.