How To Change a Car Battery

A car battery typically lasts five years, but it can be as few as two years, depending on how you drive, the average draw on the battery (the number of accessories you use in your vehicle), and how well the battery is maintained. Surprisingly, colder climates are better for car batteries, while warmer climates tend to shorten the life of car batteries due to sulfation and water loss. (Here’s how to double the life of your car battery.)

Check Your Car Battery

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Before you replace your battery, you should test it to see if its poor performance can be solved by charging it rather than replacing it. Here’s how:

Test the electrolyte in each cell with a battery tester. Squeeze the ball and draw the solution into the tester. Carefully hold the tester level and write down the reading. Squirt the solution back into the same cell. The testers are calibrated assuming a battery is at 80 degrees F. Add .04 to each reading for every 10 degrees above 80 and subtract .04 for every 10 degrees below.

If you get a cell reading that differs from the others by .05 or more, replace the battery. A fully charged battery should have a reading of 1.265 or higher. If all the readings show fair or low (1.200 is low) but are consistent, recharge the battery.

If you have a no-maintenance battery, check for a green dot in the sight glass/charge indicator. Green means the battery is good. If it’s dark, it needs recharging. If it’s yellow or has no color at all (inspect carefully and use a flashlight), replace the battery.

Poor battery performance can also be attributed to corroded battery terminals. If your terminals are too corroded, they can limit the charge the battery receives and deprive your vehicle of the voltage it needs.

How To Change a Car Battery

Changing a car battery requires just a few tools: a wrench to loosen the terminal connectors, a wire brush to clean them, gloves and petroleum jelly to spread on the terminals before connecting the new battery.

How to Remove a Car Battery

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• Remove the battery hold-down clamp.
• Disconnect the negative (black) cable first with a wrench.
• Disconnect the positive (red) cable.
• Lift the battery out by the strap. Inspect the battery for leaks as you lift it out. Battery acid is highly corrosive and can damage.

How to Install a New Car Battery

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• Check to see if your new battery needs charging before installing it. The staff at the auto parts store can do this for you. They will top off the charge if needed.
• Place the new battery in the cradle.
• Connect the hold-down clamp.
• Smear petroleum jelly (or dielectric grease) on the battery terminals to help fight corrosion.
• Attach the positive terminal first and then the negative terminal.

Properly Recycle Your Old Car Battery

You can typically return your old car battery to the place where you purchased your new battery. You’ll receive a credit for bringing back the old battery, this is called a “core charge.” You can also contact your local waste center or recycling center to see if they’ll accept old batteries.

Learn more about car battery care and the signs of when to replace your car battery.