How to Change a Battery in a Car

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Article QuickTakes:

• Safety first
• Gather what you need
• The process
• Battery disposal

If your attempts to start your car are met with a clicking noise, it’s likely time to replace your car’s 12V battery. This component lasts for about five to seven years, and as it ages, it loses its ability to hold a charge. Fortunately, changing a car battery is a fairly straightforward process.

Safety First

Car batteries contain harmful chemicals that may cause burns or irritation when exposed to your skin or eyes. It’s a good idea to wear long sleeves and pants for this job, as well as work gloves and goggles.

Gather What You Need

Consult your owner’s manual to find out how to access the battery—it’s usually under the hood—and the size and type of replacement battery you should buy. You’ll also need a wrench to remove the nuts holding the clamps around the terminals. Lastly, you should have a wire brush, a battery-cleaning product, an anti-corrosion solution, and shop towels on hand to clean the housing and prepare the new battery for use.

The Process

Locate the battery and remove its cover, if it has one. Identify the positive and negative terminals: The positive terminal should have a plus sign by it and a red cap, while the negative terminal may have a minus sign near the post and a connection to a black cable. Starting with the negative terminal, use your wrench to remove the nut securing the cable to the battery. (Be careful not to let this nut fall into the engine bay, as you’ll need it later.) Detach the cable from the terminal and set it off to the side, away from the battery. Next, pop the cap from the positive terminal and repeat the process.

Remove any clamps or brackets holding the battery in place, then carefully lift it from its housing. Clean and thoroughly dry the tray and cable clamps with battery cleaner before installing the replacement unit.

Slide the new battery into place, making sure the terminals are next to their respective connectors. If you removed a brace or clamp to extract the old battery, reattach it now.

Next, remove the covers from the new battery’s terminals and spray each post with an anti-corrosion solution. Then you can reconnect the cables. Starting with the positive terminal this time, reattach the wiring clamp and secure it with a nut. Do the same for the negative terminal. Check that everything is secure (and that you didn’t leave any tools around the battery), then cap the positive terminal with the red plastic cover.

Test your handiwork by starting the car. If you wired everything correctly, it should fire to life. Note: You may have to adjust your car’s cabin clock and reprogram your radio presets after replacing a car battery. Some car radios may also require an unlock code that can sometimes be found on a card with your owner’s manual.

Battery Disposal

Batteries are full of hazardous chemicals, which can harm the environment if disposed of improperly. In fact, your state may have specific rules dictating what you can do with a dead car battery. In general, though, you’ll want to double-bag it in plastic and take it to a recycling center or auto parts store as soon as possible. Be sure to keep the battery upright during transport to prevent leaks.