Car Battery Glossary

Car Battery Glossary

Learn the basics.

Explore common terms you’ll come across when choosing, replacing, or maintaining a car battery.

A–F

AGM (Absorbent Glass Mat)A type of battery where the electrolyte is held in glass fiber mats. Known for long life, fast recharging, and durability in stop-and-go traffic.
AlternatorCharges your battery and powers electrical systems while the engine is running.
CCA (Cold Cranking Amps)A measure of a battery’s ability to start your car in cold weather.
CorrosionA white or bluish buildup around battery terminals that can interfere with performance. It’s caused by acid vapors and moisture.
Cranking Amps (CA)Similar to CCA but measured at 32°F. Indicates starting power in moderate weather.

G–P

Lead-Acid BatteryThe most common type of car battery. Uses lead plates and sulfuric acid to generate power.
Maintenance-Free BatteryA sealed battery that doesn’t need you to add water or check acid levels.
Negative TerminalMarked with a “–” sign, it connects the battery to the car’s chassis ground.
Positive TerminalMarked with a “+” sign, it connects the battery to the starter and electrical system.

R–Z

Reserve Capacity (RC)How long the battery can run your car’s systems if the alternator fails—measured in minutes.
SulfationCrystals that form on lead plates when a battery is undercharged, reducing performance and lifespan.
TerminalThe connection points (positive and negative) on top or side of the battery.
VoltageA measure of the battery’s electrical potential. Most car batteries are 12 volts.
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About Clarios

Every journey matters.
And so does the battery
that powers each of them.

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Clarios creates the most advanced battery technologies for virtually every type of vehicle. We are a global leader in energy storage solutions, powering one in three of the world’s vehicles. We partner with our customers to develop smarter solutions that make people’s lives better.