You may not give your car battery enough thought.

Battery trouble is a leading cause of roadside breakdowns, according to AAA research. Yet most people don’t periodically test their car battery. A battery on the brink of dying rarely warns you before it fails, but getting a simple battery test can.

Here’s what makes your car battery tick—and how you can get help predicting when your car battery life is nearing its end:

How a car battery works

A car battery creates electricity through a chemical reaction. A series of lead plates contained in cells interact with an electrolyte. The resulting chemical reaction generates electrons, which travel through an outside circuit to create an electric current.

When you turn on your car’s ignition, the electrical charge is released to the ignition system to start the engine. Once the car is running, the battery’s job is done and the chemical process reverses, recharging the battery as you drive.

Car battery types

Most cars use flooded lead-acid batteries, but newer models with high electrical loads require an enhanced flooded battery or absorbent glass mat design.

Installing the wrong battery type can impact electrical system performance and battery life. That’s why AAA recommends replacing a battery with the same type that came in the vehicle from the factory. Consult your owner’s manual for more information.

Car battery life: why it dies

Over time, lead sulfate crystals form on a battery’s lead plates. When the plate coverage reaches its threshold—typically after three to five years of use—the battery can’t produce enough electricity to start the engine.

There are many things that can impact car battery life:

  • Extreme temperatures, especially heat
  • Inactivity and excessive short drives
  • Lack of maintenance, such as letting corrosion build up
  • Technical problems, such as electrical issues or a faulty charging system
  • Human error, such as storing your key fob too close to the vehicle or leaving accessories plugged into always-on power outlets

Car battery life: warning signs

Most dying batteries don’t show symptoms, but they could include:

  • Car slowly cranks when you’re trying to start it
  • A grinding, clicking or buzzing sound when you turn on the ignition
  • Dim headlights, especially when your car is idling
  • The battery warning light is illuminated
  • Corrosion, cracks or bulges on your battery

Bottom line: If your car battery is more than three years old, test it every year. It’s free for AAA Members at a local AAA Approved Auto Repair Facility.

AAA Mobile Battery Service

All batteries die, but you don’t have to be stranded when it happens. Contact AAA’s Mobile Battery Service and we’ll come to you to perform a battery and electrical system test.

Plus, if you purchase a new AAA battery (which includes a six-year limited warranty), you can see the cost with your AAA Member discount using the Instant Battery Quote.

Get an Instant Battery Price Quote

In need of a new battery? AAA has you covered. With AAA Mobile Battery Service, we may be able to install one on the spot.

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