The giving off of oxygen gas at positive plates and hydrogen at negatives, which begins when charge is something more than half completed-depending on the rate.
Electrolyte that has been immobilized by the addition of a chemical agent, normally fine silica, to prevent spillage. Batteries made with gelled electrolyte are often referred to as Gel batteries. Gel batteries are one typical type of VRLA battery.
A contraction of the term “specific gravity,” which means the density compared to water as a standard.
A lead alloy framework that supports the active material of a battery plate and conducts current.
The reference potential of a circuit. In automotive use, the result of attaching one battery cable to the body or frame of a vehicle that is used as a path for completing a circuit in lieu of a direct wire from a component. Today, over 99% of automotive and LTV applications, use the negative terminal of the battery as the ground.
A set of plates, either positive or negative, joined to a strap. Groups do not include separators.