Skip the auto shop - Our mechanics make house calls

How Can I Tell If My Car Battery Needs Replacing?

battery replacement

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

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed Related Trouble Codes: P2441: EVAP Vent Valve Stuck Open EVAP trouble...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...
P0359 OBD-II Trouble Code: Ignition Coil I Primary/Secondary Circuit Malfunction
P0359 code definition The P0359 code indicates that a fault has been detected in one of the vehicle’s ignition coils, generally the number 9 coil. This code can also be associated...

Related questions

Q: While on the interstate, displays lit up and steering locked

The engine peripherals that are driven by the belt need to be checked to make sure that they are all able to rotate without issue. If the engine peripherals check out okay, then the belt can be replaced and this...

Q: car will not crank and ECM.fuse keep blowing and no reverse lights will bad neutral safety switch cause this?

It sounds like you have an electrical issue. Check the DTC connector to make sure you are getting power and ground. A short to ground could be the cause of this concern. It may be possible that the reverse safety...

Q: Car won't start

Hi there! There first thing to check is your battery voltage. This can be done with a multi-meter. Simply place the red probe to the positive terminal and the black probe to the negative terminal, you should get at LEAST...