Here's some hot news for car owners: Summer is the season for major car-battery problems.

Virtually everyone who's been through a harsh winter is familiar with the annoyance of a "dead" battery and the need for a jump start. So it may surprise many to know that it's heat, not cold, that shortens battery life.

According to the Car Care Council, the average life of a battery is 31/2 years-even shorter in warmer climates. That's because excessive heat and overcharging are the two main reasons for shortened battery life. Heat causes battery fluid to evaporate, which damages the internal structure of the battery. A malfunctioning component in the charging system, usually the voltage regulator, allows too high a charging rate. That's slow death for a battery.