About batteries: VRLA or Valve Regulated Lead Acid

Oddly enough, recombinant batteries are seldom referred to as such, but with the term VRLA (Valve Regulated Lead Acid) or SLA (Sealed Lead Acid). These terms refer to the safety valve and the sealed lid. Both elements are important of course but only so because they allow the recombination process to take place. The full name of a VRLA battery should be: Valve Regulated Recombinant Lead Acid Battery.

To produce a recombinant battery, is a more or less solid electrolyte is needed through which the oxygen can travel to the negative plate. In time two techniques have been developed to immobilize the electrolyte: Gel and AGM. Both of these techniques serve the same purpose, namely a maintenance-free, safe and sustainable energy source. Both types have the sealed construction and the self-closing pressure valve in commen. The only, but not insignificant difference lies in the electrolyte and the separators.

Because gel batteries are on the market for over 50 years, gel has become synonymous with the recombinant battery, and the term is often used when the battery in question is of the AGM type, which were developed twenty years later. This can be very disturbing, since AGM and gel batteries have very different charging parameters.