Summer is Hard on Vehicle Batteries

Ask any drivers what is likely to take its biggest toll on car batteries—summer or winter—and most will probably say winter.

And they’re wrong: The hotter the summers, the shorter a battery life.

Check the U.S. map from Firestone Complete Auto Care that shows average life expectancies for car batteries by region. The regions run mostly east-west, but the farther south you go, the shorter the expectations. The pockets with the absolute shortest battery life expectancies are in the very hottest spots along the southern edge and in the sun-baked Southwest.

The chain also has a virtual battery tester that tells you how often a battery in your make and model should be changed where you live.

Signs of a Weakened Battery

Slow cranking is the most obvious sign of a weak battery. Your vehicle should crank fast in warm weather. It will always crank slowly on a harsh winter morning because the oil is thick, offering more resistance and taking longer to reach moving parts. Colder temperatures also temporarily lower the power reserve.

Corrosion on battery terminals can slow cranking in any weather. If there’s white or greenish residue, disconnect the positive cable and clean the terminals with a wire brush. Protect your eyes and hands. To prevent more corrosion, reconnect the positive cable, then coat with a battery terminal spray, available at parts stores.

If your battery is bloated, it may be heat damaged. Have it checked.

Check the sticker showing the battery’s age. If the date is more than three years old, especially where battery life is short, have it checked.

Keep the fluid topped in a battery with removable caps. A battery with fixed caps may have a window for checking the level. If it has fixed covers and low fluid, have it checked.

If power is low and the battery shows no physical degradation, have your alternator checked. It may not be recharging the battery properly.

Free Testing, Charging

AutoZone parts stores—almost 5,500 in the U.S.—test batteries and charging systems at no cost while they’re still on your car. That means you can find out if your battery, alternator or regulator is bad when your battery dies.

If your battery goes dead because you left a light on overnight or a device charger plugged into your 12V outlet, AutoZone will even charge it while you wait. You must carry the battery into the store. The company says its fast charger needs about a half-hour to fully replenish a 12-volt battery.

How To Preserve Your Battery

Here are ways to keep your battery strong:

• Don’t let a vehicle sit for long periods without being driven or the battery reserve will diminish.
• Avoid taking only short trips. Occasionally drive longer than 20 minutes to recharge the battery.
• Don’t warm your car for 15 or 20 minutes with the radio, heat and defrosters, or air-conditioner running. They drain a battery unless you follow up by driving long enough to fully recharge the battery.
• Take two or three seconds to turn accessories off before leaving your car. Leaving your radio, wipers and heater or air-conditioner on strains your battery when you restart.
• Avoid extreme temperatures if possible. Getting your car under cover—not even in an air-conditioned or heated space, just in a garage or carport—helps preserve battery life.
• Never leave a light on or a device recharging overnight. Some vehicles, when not running, don’t charge a device, but others do.

Avoid allowing your battery to discharge completely and repeatedly.

A battery older than three years is a possible candidate for replacement, and if four years or older, a definite candidate. Consider replacing it to avoid its failure at an inopportune time. Always buy a battery with the same or more cold cranking amps (CCA) as your old battery.