What is a VRLA battery?

A Valve Regulated lead-acid (VRLA) battery is a lead-acid electric storage device that has the electrolyte (acid) immobilized:

1. by adding a silica additive that works to convert the electrolyte into a GEL-like material or consistency for GEL VRLA DRY CELL types
2. absorbed into a woven glass fibre sponge-like material called an Absorbed Glass Mat for AGM VRLA DRY CELL types