Installation Manual

37
LEAD ACID BATTERY GLOSSARY
ABSORBED (OR ABSORPTIVE) GLASS MAT
A technique for sealed lead-acid batteries. The electrolyte is absorbed in
a matrix of glass fibers, which holds the electrolyte next to the plate and
immobilizes it, preventing spills. AGM batteries tend to have good power
characteristics, low internal resistance, and good behavior during charging.
AMP, AMPERE
Unit of electrical current. Abbreviated “A”.
AMP-HOUR
Unit of electrical energy, one amp of current flowing for one hour.
Abbreviated Ah.
CELL
A single battery canister usually grouped together with other cells to form
battery packs of different voltages and amperages. Example: One NiCD cell is
1.20 volts; therefore, six cells packaged together makes a 7.2 volt battery pack.
CYCLE
A “cycle” is a somewhat arbitrary term used to describe the process of
discharging a fully charged battery down to a particular state of discharge.
The term “deep cycle” refers to batteries in which the cycle is from full charge
to 80% discharge. A cycle for an automotive battery is about 5%, and for
telephone batteries is usually 10%.
ELECTROLYTE
An electrically conductive medium in which current flow is due to the
movement of ions. In a lead-acid battery, the electrolyte is a solution
of sulfuric acid. In other batteries, the electrolyte may be very different.
FLOODED CELL
A design for lead-acid batteries. The electrolyte is an ordinary liquid solution of
acid. Flooded cells are prone to making gas while being charged. They must be
periodically checked for fluid level and water added as necessary. Flooded cells
are also typically less expensive than AGM or gel type lead-acid batteries.
HYDROMETER
A tool for testing the specific gravity of a fluid, such as the electrolyte in a
flooded battery. Typically, a squeeze-bulb is used to suck up a sample of the
fluid, and a float indicates the specific gravity.