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How to Tell If Your Car Battery Is Dead (3 Signs to Look For)

Jumper cables

Your car’s battery is the heart of your vehicle, and without it, you won’t be going anywhere in a hurry. It’s also an essential component in order for the lights and dashboard controls to work. There are several reasons for your car not starting, and a dead battery is just one possibility, though usually the cheapest option to fix, so you’ll want to check if that is the problem first, before spending money unnecessarily at a mechanic.

There are a few things to look for to diagnose a dead battery. “Dead” for a battery can mean a few different things: It may just be so drained that it cannot start your car and thus, will just need a jump start. Or it may be dead in every sense of the word, which will mean a trip to the mechanic and a replacement.

Here are three surefire signs that you’ve got a dead battery on your hands.

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1. Your Car’s Ignition Is Still Turning but Not Starting

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This may seem like an obvious point, but if your car won’t start, your battery could be dead. If you turn the ignition key, and the starter motor still makes a labored sound, jumper cables and a friend’s car are probably all you need. However, there are other reasons that it won’t start, like a faulty starter motor or ignition switch or even just a blown fuse. However, an ignition switch or starter motor will usually show signs of slow death before they give up. So, how do you diagnose the battery as the problem? If you answer yes to any of these questions, it’s likely your battery:

  • Has your car been standing for an extended period?
  • Did you leave your headlights on?
  • Did you leave your radio on?

One last thing to do is check your fuse box and make sure none are blown. If that’s all good, your car may just need a jump start.

2. No Ignition

Car keys
Photo By: PIRO4D, Pixabay

If you answered yes to any of the above, and you turn the key and there is no sound at all, the battery is likely completely dead and will need a good charge before you can start the car. If your car jump-starts easily, let it run for about 20 minutes or so to charge the battery up. If it won’t start again after this, it’s probably time for a replacement.

3. No Dash Lights or Headlights

Car headlight
Photo Credit: Car headlight by wilkernet, Pixabay

Turn your ignition key on, and check if you have any dash indicator lights. Now try your headlights. If either are dim or not working at all and you answered yes to any of the above questions, you likely have a dead battery on your hands. A jump-start may help, but your battery will need a good, long charge if the lights aren’t working.

Other Reasons for a Dead Battery

If you answered no to all the above questions and your battery is still dead, there are a few other possibilities. There may be an underlying short that is slowly draining the battery overnight, but that is something only an auto electrician can diagnose.

A basic multimeter can help you check your battery’s voltage output and see if it is still operating optimally. If it’s putting out less than the standard 12 volts, it’s likely getting old, and it may be time for a replacement. Anything around 10.5 volts or under, and there is the risk of serious problems. The terminals eventually become coated in hardened crystals of lead sulfate and will eventually damage the battery terminals in your engine. If it is still putting out a good charge, there may be a short that is slowly draining it.

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There are other additional checks to diagnose a dead battery. Corroded terminals and loose wires can also be the culprit for intermittent starting. Make sure the terminals are tightly fitted to the battery posts — you should not be able to move them with your hands. This will ensure your battery is being charged efficiently.

Cold weather is another common factor. The cold will reduce the battery’s storage capability, especially with snow and frost. If you live in a cold climate, you can mitigate this by parking your car in a garage or undercover. It those options aren’t available, a good old thick, woolen blanket draped over your car’s hood is a common cold-weather hack! If you park your car undercover and the car still won’t start, something else may be draining it.

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Batteries do have a limited lifespan, and you’ll generally need to replace your battery roughly every three years. There are factors that can extend its lifespan: good, clean terminals, not letting it drain often, and checking the water level regularly.

Remember, nothing can replace the experience and expertise of a professional mechanic, and it’s always a good idea to consult them first if possible. We hope that we’ve helped you diagnose your battery issue and that a jump-start is all you need!

Featured Image Credit: StockSnap, Pixabay


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