How to Change a Car Battery
Time Required: Under 2 hours
Your car won’t run with a dead battery. While this can be a major inconvenience, there is a simple solution. Avoid tow truck costs and a trip to the auto repair shop with this step-by-step guide on how to change a car battery.
Safety Note: Even if you think a battery is completely dead, never let any metal object touch both the black/negative (-) and red/positive (+) posts on the battery at the same time. This is very dangerous as it creates a current that can spark, heat or even explode.
- Make sure the car is in park and the emergency brake is engaged.
- If you’re parked on an incline, place a wedge or wooden block behind your vehicle’s tires to ensure it stays secure.
- If the car is parked in a garage, make sure the garage door remains open.
- Turn engine off and pop open the vehicle’s hood.
- Make sure the engine and any nearby car parts are cool enough that you can safely work in that area.
- Depending on the make and model of your vehicle, the battery may be located under the hood, in the trunk, or elsewhere.
- Part or all of the battery may be covered, which you will need to remove.
- If you have a hard time locating the battery, consult your owner’s manual.
- Car batteries, like regular AA batteries, have positive and negative ends.
- The positive (+) end is identified with a red plastic cover or connected to red wires, while the negative (-) end will have black markings.
- Always remove the negative cable first. Use a wrench to loosen the nut on the black/negative (-) end of the battery.
- Detach the black/negative (-) cable from the battery.
- Detach the red/positive (+) cable from the battery.
Tip: If the battery is hard to remove, you can use a battery terminal puller. Do not use any tools to try to pry up the cable as it may cause damage. Never allow a metal object to touch both ends of the battery.
- Remove the clamp holding down the battery. There may be several clamps, so inspect the outside of the battery carefully.
- Set the clamps and fasteners aside and remove the battery from its tray.
- Be careful when you remove the battery as they can be heavy (between 40 and 60 pounds). Keep your hands steady to avoid jostling the battery or spilling acid from the battery. If the battery has a handle, you can use that.
Tip: Use a bowl or magnetized plate to collect all the loose pieces as you are removing a car battery. This will prevent them from falling into the car.
- Use a wire brush with a battery cleaning solution or a mixture of baking soda and water to clean the battery tray and connector wires.
- Dry everything completely.
- Do not install a car battery if there are any wet parts remaining.
- Remove the red and black plastic covers on the ends of your new battery.
- Prepare your new battery for use by installing anti-corrosion washers on both battery posts. You may also spray both of the car’s terminal ends with anti-corrosion solution.
- Place the new battery in the battery tray, aligning the red/positive (+) and black/negative (-) ends of the battery with the matching terminals and cables.
- Re-install the clamp(s) the same way you removed them in order to secure the battery.
- Connect the positive end first. Attach the red/positive (+) cable to the red/positive (+) battery post and tighten with a wrench.
- Do the same on the black/negative (-) side.
- Ensure that the connections on both ends are secure by trying to move the battery around.
- If it shifts at all, check all the clamps and check the tightness of the cables.
- If the battery was originally covered, reinstall its cover the way it was removed.
- Close the hood and start the car.
Tip: If the car still doesn't start after changing the battery, have it serviced by a certified technician.
Car batteries have very specific disposal requirements. Follow local laws and bring it to the appropriate location for recycling. Shop our selection for all the tools you need to change a battery in your vehicle. The Home Depot delivers online orders when and where you need them.