What does VRLA mean?
VRLA stands for Valve Regulated Lead Acid. VRLA batteries are sealed batteries equipped with pressure safety valves. Under normal conditions these valves stay closed, and prevent any gas escaping or loss of electrolyte. However, if charging currents become too high, or the battery overheats, the gas pressure produced inside the battery may open these valves, causing gases and electrolyte to vent. Once these have escaped there is normally no means to replace them, so the battery will permanently lose some capacity.
