Common Battery Terms

Common Battery Terms

Common Battery Terms:

- Ah -Amp Hour Capacity
This rating is derived from discharging a fully charged battery at a constant amp draw for 20 hours @ 80 °F without the voltage of the battery falling below 10.5 volts. The constant amp draw is multiplied by the 20 hours to come up with the Amp Hour Rating.

- CCA -Cold Cranking Performance
Represents the amperage capacity a fully charged battery can deliver @0 °F for 30 seconds before the voltage of the battery falls below 7.2 volts.

- RC -Reserve Capacity
Reserve capacity is expressed in minutes and relates to the amount of time a fully charged battery can maintain a constant draw of 25 amps @ 80 °F before the voltage falls below 10.2 volts.

- W -Watts
The measurement of electrical power that the battery can deliver for a cold start. It is calculated by multiplying the starter amperage draw @ 0 °F times 10 volts.

- V -Volt
Unit of measure of potential difference (Electrical pressure).

- A -Amp
The current flow in a circuit. Value is proportional to the number of electrons flowing past a point in one second.

- Ohm
The measurement of the resistance of a component or circuit to current flow.

- Electrolyte
The mixture of sulfuric acid and water. 35% sulfuric acid, 65% water.

- Specific Gravity
The measurement (by weight) of the volume of sulfuric acid in the electrolyte. A specific gravity of 1.275 (the specific gravity of a fully charged battery) means that the electrolyte is 1.275 times heavier than water. The specific gravity of water is 1.000.

- Sulfate
Deposits formed on the plates of the battery as the electrolyte gives up its sulfuric acid. Excessive deep cycling of a battery can cause a hardening of this deposit and make it impossible to return sulfate to the electrolyte. A sulfated battery is one which has these hardened deposits on the plates and cannot be recharged to full capacity.

- OCV Open Circuit Voltage
The measurement of the voltage of a battery across the terminals.