VRLA batteries electrochemical factors affecting life

Valve-regulated -lead–acid (VRLA) batteries have been revealed as showing an impressive cycle life performance, which compared with the equivalent flooded type, yields increments as large as three–five times. These impressive results have been achieved even though components, such as lead–calcium alloys, which are not especially adequate for obtaining high cycle lives are used. The report is concerned with the electrochemical factors, that determine such performance. The development of the new ORBITAL™ battery, especially the cycling version, has been possible, through an optimisation process of the parameters determining life performance. In this way lives approaching 1000 cycles at 60% depth-of-discharge (DoD) have been achieved, which open the possibility to use such batteries in cycling applications, up to now restricted to other technologies like gel batteries. A review of the electrochemical factors, determining such performance is presented in an attempt to highlight the electrochemical basis of VRLA performance.