The unit of measure of the electron flow, or current, through a circuit.

Ampere Hours

The unit of measure for a battery’s electrical storage capacity, gained by multiplying the current in amperes by the time in hours of discharge.


The unit for storing chemical energy and converting and discharging this energy as electrical current.


The Number of ampere-hours (Ah) a fully charged cell or battery can carry under certain conditions of discharge.


Basic electrochemical unit that is used to store electrical energy.


The process of restoring electrical energy to a cell or battery.


Polypropylene or hard rubber case. It holds the battery plates, straps and electrolyte.


Damaging chemical reaction of a liquid electrolyte with a reactive material.


The process of discharging plus recharging a battery.

Cycle Life

The number of cycles a cell or battery provides before failure.

Cycle Use

A method of using a secondary battery repeatedly by charging and discharging.

Deep Discharge

The state in which a cell is fully discharged using low current, so that the voltage drops below the final discharging voltage.


The process of battery current delivering.


A conducting mass that includes materials, which are capable of reacting with the electrolyte in a cell to produce or accept current.


The material in a cell that transfers electrons between the electrodes, conducts ions in the cell.


The electrochemical decomposition of water from the electrolyte.

Float charge

A Method of charging in which a secondary cell is continuously connected to a constant-voltage supply that maintains the cell in a fully charged condition.


The lead alloy framework that supports the active material of a battery plate and conducts current.


A divider between the positive and negative plates of an element which allows the flow of current to pass through it.


Formation of lead sulfate crystals on the plates of a lead-acid battery.


External electric connections of a cell or battery.

Valve Regulated Lead Acid (VRLA) Battery

Sealed lead acid and maintenance free batteries.


Electromotive force or potential difference, expressed in volts (V).

Watt Hours

A way of expressing the capacity in terms of energy in a cell.