Contact Us

Zhongneng Chengyu Power Co.,Ltd

Address: No.216 Changjiang Road, Huangdao Development District, Qingdao City, Shandong Province, China


Tel: +86-532-86934246

Fax: +86-532-86934246

Valve regulated (VRLA) battery

- Jan 22, 2018 -

Valve regulated (VRLA) battery

In a valve regulated lead acid battery (VRLA) the hydrogen and oxygen produced in the cells largely recombine into water. Leakage is minimal, although some electrolyte still escapes if the recombination cannot keep up with gas evolution. Since VRLA batteries do not require (and make impossible) regular checking of the electrolyte level, they have been called maintenance free batteries. However, this is somewhat of a misnomer. VRLA cells do require maintenance. As electrolyte is lost, VRLA cells "dry-out" and lose capacity. This can be detected by taking regular internal resistance, conductance or impedance measurements. Regular testing reveals whether more involved testing and maintenance is required. Recent maintenance procedures have been developed allowing "rehydration", often restoring significant amounts of lost capacity.

VRLA types became popular on motorcycles around 1983, because the acid electrolyte is absorbed into the separator, so it cannot spill. The separator also helps them better withstand vibration. They are also popular in stationary applications such as telecommunications sites, due to their small footprint and installation flexibility.

The electrical characteristics of VRLA batteries differ somewhat from wet-cell lead–acid batteries, requiring caution in charging and discharging.

Previous: Deep-cycle batteries Next: Absorbed glass mat (AGM) battery

Related Industry Knowledge

Related Products