Top 5 Key Players companies in VRLA battery
by Most Patent Filings in the United States in 2018

A valve-regulated lead-acid battery (VRLA battery) sometimes called sealed lead-acid (SLA) or maintenance free battery, is a type of lead-acid battery. There are three primary types of VRLA batteries, sealed VR wet cell, absorbent glass mat (AGM) and gel cell. Gel cells add silica dust to the electrolyte, forming a thick putty-like gel. These are sometimes referred to as "silicone batteries". AGM (absorbent glass mat) batteries feature fiberglass mesh between the battery plates which serves to contain the electrolyte and separate the plates. Both designs offer advantages and disadvantages compared to conventional batteries and sealed VR wet cells, as well as each other.