How to Test a Car Battery [Easy Guide]

Car batteries will last anywhere from three to five years, sometimes even longer. The lifespan of the battery depends on the use, climate, and quality of the battery itself. Having a bad battery can cause a series of problems and to stay on top of that, I suggest checking your car battery once it reaches 3 years of age.

Also, I had an electrical issue with my vehicle not too long ago. I went to the mechanic shop and they suggested that I get a new car battery even though my battery was just 14 months old. So, I was a bit skeptical, to be honest. That’s why I went straight home and tested my car batteryOpens in a new tab.

So, before you take your car to the mechanic shop and replace your battery, let me show you how to test your car battery. Let’s dive into the details and by the end of this article, you will know how to test a car battery.


How To Test a Car Battery

A worn or faulty battery will cause no starts, engine turning over slow especially in the cooler weather, battery discharging quickly, electrical malfunctions in your vehicleOpens in a new tab.

That’s why I have put up this easy guide on how to test a car batteryOpens in a new tab.

1. Required tools for testing a car battery

How to Test a Car Battery

In order to test a car battery, you will need some equipment. Keep in mind that the battery testing equipment is affordable and can last you for a long time. You will need:

  1. Digital multimeter. The digital multimeter for car batteries that I got is less than $20 and you can order it on amazon.comOpens in a new tab.
  2. Digital battery analyzer. You will need a digital battery analyzer to test the CCA which stands for Cold Crank Performance(amps). I got my battery analyzer for around $30 on amazon.comOpens in a new tab.

2. Locate and remove the car battery

How to Test a Car Battery

Once you have your battery testing equipment in order, the next is to locate the car battery. In most vehicles, the battery is located under the hoodOpens in a new tab.

Disconnect the battery terminals using the appropriate tools. Always start with the negative terminal first to reduce the chance of a short when using your tools. Once the negative clamp has been removed, then move on to the positive. Then, remove the hold-down clamp. Take out the car battery while holding it leveled so you don’t spill out any acid from the vent holes.

IMPORTANT: When charging or testing your car battery, always do this in a well-ventilated area so there’s no risk of fumes building up which could risk an explosion.

3. Test the voltage using a multimeter

How to Test a Car Battery

Before testing the battery, you will need to ensure that the terminals are clean. Set the multimeter to the two-digit DC voltage setting. Then, touch the appropriate probes on the negative and positive terminals. The black goes to the negative and the red to the positive terminal.

A properly working 12V car battery should have a reading between 12.7V and 11.9VOpens in a new tab.

4. Test the cold-cranking performance

How to Test a Car Battery

Testing the CCA or the cold-cranking amps can be done with a battery analyzer tool. The car batteryOpens in a new tab.

On this particular battery that I am performing a test, the CCA is 410 on a temperature -18 degrees Celsius or 0 degrees Fahrenheit. Connect the red positive clamp onto the positive terminal of the battery and the black clamp onto the negative terminal of the battery. Turn on the battery analyzer tool and select the type of battery and the CCA written on the battery.

If you get a reading lower than what is written on the CCA label, then you will need to replace your car battery. I’ve tried recharging my old battery but simply it was just a waste of time and energy. Once your car battery goes badOpens in a new tab.

5. Install a new battery or reinstall the old one

Once all the testing is done, you will know if your battery is up for a replacement or not. Like I said before, if you have a bad car batteryOpens in a new tab.

Whatever you decide to do, place the battery in the same position as before and tighten the hold-down screw first. Be careful not to touch the clamps. Attach the positive terminal first and then the negative.

Igor Iwanowski

I am a certified Automotive Service Excellence (ASE) mechanic since 2018. I specialize in Brake systems, dashboard warning lights, EGRs, general engine problems, EVAP and Emissions issues.

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