Article from carcare.org, July 10, 2012

Summer’s extreme temperatures can destroy a vehicle’s battery. The Car Care Council advises vehicle owners to have their cars’ batteries tested periodically and replaced, if necessary, to avoid being stranded.

Excessive heat and overcharging shortens the life of a battery. Heat causes battery fluid to evaporate, which then damages the internal structure of the battery. A malfunctioning component in the charging system, usually the voltage regulator, allows too high a charging rate, which will eventually destroy a battery.

“When most motorists think of dead batteries that cause starting failure, they think of severe winter weather, but summer heat is the real culprit,” said Rich White, executive director, Car Care Council. “Many battery problems start long before the temperatures drop. A few simple steps now can help you avoid the cost and inconvenience of a breakdown later.”

To get the most life out of a battery, the Car Care Council suggests the following:

• Be sure the electrical system is charging at the correct rate; overcharging can damage a battery as quickly as undercharging.

• If your battery is the type that needs to be topped off, check it regularly, especially in hot weather. Add distilled water when necessary.

• Always replace a battery with one that’s rated at least as high as the one originally specified.

• Keep the top of the battery clean. Dirt becomes a conductor, which drains battery power. Further, as corrosion accumulates on battery terminals it becomes an insulator, inhibiting current flow.