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.
To get the most life out of a battery, the Car Care Council (www.carcare.org) 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.