AAA Mobile Battery Service

When the temperature drops near freezing, a battery maintainer or trickle charger may not keep your battery alive. But it’s not the battery charger’s fault; it’s that the weather is too cold.

Recharging your car battery any time is a good idea to extend its life. However, at 32 F, a typical battery is only 65% efficient, both at recharging and giving power. This means you'll need more voltage or hours to recharge. In fact, your alternator may not be able to give your battery all the power it needs to spring back to life unless you’re traveling a long distance.

Your best move is to visit a repair shop. If a test shows significant weakness, a shop will have equipment to recharge your battery.

If you suspect your battery is frozen, don’t do anything. Do not try to crank or jump-start a battery with:

• Bulges
• Cracks
• Icicles
• Frost on the terminals or plastic case

Driving every day keeps cold-weather damage at bay, since the car engine warms the battery. A good rule of thumb is to drive the length of your commute, even during holiday breaks.

The average commute in the United States and Canada is more than 20 minutes one way, according to the U.S. Bureau of Statistics and Statistics Canada. Driving a similar distance—to a cafe, the in-laws, or a grocery store on the far end of town—can keep your battery healthy.

However, visit a repair shop the moment your car is slow to start. That’s an early sign your car battery is on its way out, and driving won’t revive a dead battery.

Ambient temperatures during cold weather can kill your battery. When it's cold, park in these places whenever possible:

• In your garage
• In parking garages with a lot of come-and-go traffic
• Near heated equipment
• Close to warm buildings
• In spaces with lots of direct sunlight, which will warm the car
• Anywhere warmer than shaded, direct outdoor weather

How warm does it need to be? That depends on your car battery’s size, power, and age. The weaker the battery, the warmer it has to be to ensure you can start your car. 

Battery warmers, insulators, electric battery blankets, thermal wraps are all corrosion-resistant heat blankets you can buy to protect your battery. 

In a pinch, throw a dry, thick bath towel on the battery after you’ve driven enough to warm the engine. As soon as you park, pack the towel onto the battery. The extra coating will retain engine heat. Be sure to remove the towel before starting the engine again.