How to Tell if Your Car Battery Is Dead

When your car won't start, it's easy to start worrying about potential problems with the engine or electrical system. Before you panic, consider the fact that you may simply have a dead car battery. While annoying, this problem is a lot easier (and cheaper) to fix than engine issues. Learn more about how to tell if your car battery is dead and what to do if it is.

Common Problems to Look For

First, check your lights. If the controls were left in the "on" position, you may have accidentally drained your battery. If the controls are in the "off" position, try to turn on the lights. If they work, your battery may not be the problem. You may have a faulty starter or other problem preventing your car's engine from turning over.

A car that occasionally refuses to start without a reason may have an old or weak battery. Open the hood and look at the battery terminals. If they are frayed, have a white buildup, or seem to be leaking, it's time to consult a professional. You may need new cables in addition to a new battery.

Check Your Car Battery's Age

Most cars have batteries that last between three and five years. You can check your battery to find out how old it is with the following steps:

  • Open the hood and remove the battery cover if there is one. Look for a circular sticker with the month and year printed on it.

  • The first number represents the month and the second is the last two digits of the year. So, 04/18 means April of 2018.

  • You may also have a battery with a plastic strip or date code stamped into the top. The first letter represents the month. So, A is January, B is February, C is March, etc.

  • The second number represents the year. So, 8 = 2018, 9 = 2019,  0 = 2020, etc. If your battery is more than three years old, you may need to replace it.

"It’s a best practice to get your entire charging system tested by a professional who can inform you of any need to service or replace the battery, alternator, or other part of the vehicle," said Richard Reina, Product Training Director at CARiD.com. "If your car does not start after a jump, your battery is likely completely dead and will need to be replaced. Your choices are to call for a towing service to bring your car to a repair shop or your residence, or roadside assistance, which may make their own attempt at jump-starting. Some roadside operators are equipped to replace your battery on the spot."

What to Do if You Think You Have a Dead Battery

If you have a AAA membership or roadside assistance, call for help. Many roadside service operators can make a basic diagnosis of your problem and jump-start your vehicle if necessary. If a jump-start doesn't work or you have a problem other than your battery, they can tow you to a mechanic's shop.

If you believe your car battery is dead, you can jump-start the car with access to good quality jumper cables and someone with a running vehicle who is willing to lend a hand. Consult your owner's manual (located in your car's glove box) for instructions specific to your vehicle.

"If using a booster car, start its engine and let it run for a few minutes before trying to start your car," said Reina. "Your car’s engine should crank and start. If it starts and stalls, turn the key off, wait a few moments, and try again. It may help if the owner of the booster car slightly raises their car’s idle speed while you are cranking your car. If your car does not crank (no sound), or only elicits a clicking sound, the cable’s clamp connections may be weak. Turn off the engine of the booster car and try wiggling each clamp in turn. You may have some dirt or corrosion preventing a clean connection."

If you aren't sure why your car won't start, it's best to consult a mechanic. Having a professional diagnose the problem will help you avoid needlessly replacing expensive parts.

If you're worried about this happening to your new driver in the future, make sure to sign them up for an online driver's ed class. They'll learn how to deal with common issues like this so you can have peace of mind.

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