How to Test a Car Battery at Home (with No Equipment)

  • Oct 23,2018
Woman turning the key in her ignition Woman turning the key in her ignition

When it comes to starting your car, silence is one of the worst sounds you can hear.

That’s why it’s essential to act immediately if you:



  • Suspect your car battery is losing power (pay attention to warning signs).
  • You can’t recall the last time you replaced your car battery.


    You won’t even have to leave your driveway to conduct a quick battery check. We’ll show you how to test a car battery from home in four simple steps.

    1. Perform a load test.

    Performing any "test" on your car can sound intimidating if you’re not a technician. Luckily, this one is pretty straightforward.



  • Without starting your engine, turn on your headlights.
  • Leave them in the "ON" position for 10-15 minutes.
  • After that time passes, start your car.
  • Watch the brightness of your headlights.


    If your headlights dim noticeably as the engine turns over, your battery doesn’t pass the load test. The battery should hold enough charge to handle the 10-15 minutes before the engine starts, and once the engine turns over. If your car’s battery is struggling here, it most likely needs to be replaced before it fails you on the road.

    2. Check for corrosion.

    Besides looking like something that would ooze out of an evil scientist’s laboratory, corrosion on your car’s battery could indicate a power problem.

    Over time, that corrosion, caused when acid within the battery releases hydrogen gas, might interfere with the battery terminals’ ability to transfer power. The battery has to work harder to compensate, and that extra work can shorten its life.

    You can clean the battery terminals (carefully!) with household items like baking soda and an old toothbrush. If your battery has been suffering from corrosion for a long time, however, the damage may be irreversible. In that case, it’s time to replace.

    3. Listen for clicks.

    If anyone ever makes a horror movie about car problems, you can bet the soundtrack would be the rapid clicking of a lifeless battery!

    When you turn your key over in the ignition, you should hear a lively roar that settles into a purr. When you hear “click-click-click” instead, you know your car battery is likely dead. A single click, on the other hand, could mean a bad starter.

    Those clicks might not mean your battery needs to be replaced, but they're a reliable indicator. Even if a jump start gets the vehicle going, the first stop should be the bay of an experienced, trusted technician.

    4. Use the virtual battery tester.

    The internet’s awesomeness is beyond dispute at this point. One reason? It has everything—and keeps getting cool, new stuff!

    One example: you can now “test” your battery online with a virtual battery tester on Firestone Complete Auto Care’s website.



  • Visit our virtual battery tester.
  • Enter your car’s year, make, model, engine type, and your zip code.
  • Click the red “Find Out Now” button.


    The virtual battery tester tells you the battery’s expected lifespan. Keep in mind that factors such as corrosion or weather can alter your battery’s life expectancy and influence the test’s accuracy.

    Visit Firestone Complete Auto Care.

    The best time to replace your battery? Before you need to! If you've done this quick check and you're still unsure about your battery, visit Firestone Complete Auto Care to get a more precise (and 100% free) battery test. We can predict potential battery failures within a minute or less.

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