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What You Need to Know About Car Batteries and Heat

The summer can be rough on your battery. A CAA auto expert explains why.

Attaching cables to a car battery

Many people think that cold weather destroys car batteries. But frigid winter temperatures are usually the coup de grâce; most damage to batteries actually happens during the summer.

That’s when heat causes the water inside a battery to evaporate, setting off a chain reaction that can leave it on the brink of failure, says Ryan Peterson, manager of automotive services with CAA South Central Ontario. “If you bake it all summer long, it becomes depleted and it doesn’t have the energy left to start the car or run it properly,” he says.

All it takes is one fall cold snap and your battery is toast. Here’s what you need to know to avoid that.

1. Batteries need protection from the summer heat

Heat is the enemy of any battery, so do everything you can to keep it cool, says Peterson. If you can, park your car in the garage or under a carport or canopy. Also, consider getting window covers, which will help prevent heat from building up inside your car.

2. Batteries need a look before your summer road trip

Don’t wait until your battery bites the dust—give it a quick once-over during the summer. Look for things like a bulging case and blue-ish crystals around the terminals. Both are signs that your battery is on its way out and should be replaced, says Peterson.

3. Older batteries need a professional check

Some problems can’t be spotted with the naked eye. That’s why Peterson recommends having a technician inspect your battery annually if it’s more than three years old. “You’d rather catch [a problem] now than on your road trip. It’s just going to fail at the worst possible time.”

4. A trickle charger helps stop battery drain

Modern cars are chock full of electronic devices that draw power from your battery, even when your engine is off. (One example: lots of navigation systems switch on in the middle of the night to check for updates.) If your vehicle is idle long enough, those devices can drain your battery and potentially do lasting damage to it. So if you have a weekend runabout, or if you’re taking a long summer vacation and leaving your car at home, buy a trickle charger. It will supply your battery with a steady charge, keeping it in tip-top shape.

Getting ready for a summer road trip?

Find out what you need to know before setting up a dash cam and get five more ways to make your battery last longer.

Plus, if you’re a CAA Member, CAA’s mobile Battery Service can test your battery for free—and give you Member-exclusive pricing if you need a new one. Learn more here.

Image credit: iStock.com/thodonal