A DEAD BATTERY is one of the most common reasons drivers call CAA for help. It’s no surprise really. Canada’s sub-zero winters are like kryptonite to your car’s battery, and high-tech features—like cameras, keyless entry and automatic engine stop/start—can put additional strain on the system. Having a little knowledge of your car’s battery and electrical system can go a long way to preventing problems down the road and help you feel better equipped to interact with your mechanic or CAA professional.

HOW IT WORKS In a traditional vehicle, a 12-volt battery—often located in the engine bay or under a cover in the trunk—is responsible for supplying juice to a starter motor that spins the engine to life. Once the engine is running, it powers an alternator, a tiny generator that turns the engine’s rotating mechanical force into electrical energy. The alternator usually powers accessories, such as headlights and wipers, while the vehicle is on the move, and it recharges the battery. Electric vehicles (EVs) are powered by massive lithium-ion batteries—often positioned under the car’s floor—but they also have a smaller 12-volt battery to power accessories such as headlights, windows and wipers.

KNOW THE SIGNS A 12-volt lead-acid battery (found in most cars) usually has a lifespan of three to five years, but drivers should always be on the lookout for signs of failure. Those include slower “cranking,” warning lights on the dashboard, dim headlights, a sulfur or rotten-egg smell, a weird-sounding horn, and corrosion, which looks like white or blue-green gunk on the battery itself. A dead or dying battery can (although not always) point to a problem with the alternator. Alternator failures are less common than battery issues, but signs to watch out for include a whining or growling noise from the engine bay, a burnt-rubber smell, and flickering or dim headlights.

BATTERY TIPS To avoid battery problems, don’t run your vehicle’s accessories for an extended period while the engine is off, and check that you haven’t accidentally left the vehicle’s lights on before walking away. If your car will be parked for an extended period, consider installing a “smart” battery charger/maintainer to keep it in good shape. The best way to prevent a dead battery, however, is simply to use your car. Try to drive for at least 20 to 30 minutes once a week. If all else fails, CAA Mobile Battery Service will test, replace and recycle your old car battery at your home, workplace or even from the side of the road.

Need battery service?

Battery testing and installation is available for CAA Manitoba Members in Winnipeg and Brandon areas only. Call 204-262-6000 (Winnipeg) and 1-800-222-4357 (Brandon). Email autoadvice@caasco.ca with your automotive questions.