Lead Acid Battery

A battery with electrodes of lead oxide and metallic lead that are separated by an electrolyte of sulphuric acid.

The overall reaction is:

PbO₂ + Pb + 2H₂SO₄ <=> 2PbSO₄ + 2H₂O

Some batteries manufactured for use in very hot or very cold climates may have stronger or weaker acid. If so, it is usually marked on the battery.

Most Lead-Acid batteries will have a specific gravity in the range of 1.1 to 1.3, with most fully charged batteries being about 1.23 to 1.30 (Note: some hydrometers multiply this number by 1000, so 1.3 would read as 1300.)

A very old lead acid battery showing the arrangement of plates in each cell.

Deep Cycle

A lead acid battery designed to operate over deeper discharges, the normal design change is to use thicker lead plates.

Valve Regulated Lead Acid Battery (VRLA)

A lead acid battery that uses pressure valves that open only under extreme conditions.

See also: Absorbed Glass Mat Battery, Battery, Battery Acid, Spiral Wound Lead Acid Battery.