The Heart of Your Vehicle

By Matt Bubbers

A dead battery is one of the most common reasons drivers call AMA 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 knowledge of your car’s battery and electrical system can go a long way in preventing problems down the road and help you feel better equipped to interact with your mechanic or AMA professional.


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 power 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, and it also maintains the charge in a healthy battery (but can’t recharge a severely depleted one). 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.


A 12-volt lead-acid battery (as 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 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.


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, AMA Mobile Battery Service will test, replace and recycle your old car battery from your home, workplace or even from the side of the road.


AMA Mobile Battery Service will come to you with no-charge testing for all members. If you end up replacing your battery, your appointment won’t count as one of your annual roadside assistance calls. Call 1-800-222-4357 or use the app to request assistance.