How Can I Tell If My Car Battery Needs Replacing?

There are few things more frightening than hearing buzzing or clicking from your car when you’re trying to start it. It could mean any number of things, but chances are that it means you have a faulty car battery. You need to test your car battery, and it might be time to replace the battery, or maybe just do some car battery maintenance.

Do I have a bad car battery?

Maybe or maybe not. A car battery doesn’t last forever, but sometimes the problem isn’t really the battery – it’s simple hygiene. So the very first thing you do is simply disconnect the battery cables (negative first). Now, take a look. Do the posts and connectors look clean, or are they covered with a whitish substance? This is corrosion, and it’s preventing your car battery from communicating effectively with your car’s electrical system. So get a brush, or some steel wool, and start removing it. Don’t worry about damaging the posts and connections – that’s not going to happen. Follow up your cleaning with a coating of grease on the cable clamps and posts – plain old Vaseline will do the trick quite nicely.

Battery still won’t take a charge?

The battery’s electrolyte level could be low. This is the balance of water and sulfuric acid that delivers the charge to the rest of your car’s electrical system. YourMechanic can test your car battery using a device called a hydrometer. If the electrolyte level is low, your battery might be over-charging.

If the hydrometer reveals that the battery is fully discharged, YourMechanic will hook the battery up to a charger. If the battery won’t hold a charge, then you can probably safely assume that you have a bad car battery that needs to be replaced.

Still no start?

If you’ve performed these car battery maintenance tasks, and your car still won’t start, you’ll need to explore other possibilities. A proper battery inspection by a mechanic could be helpful in this situation.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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