How to Replace Your Car's Battery

Lead Image
  • 1-2 hours
  • Beginner
  • 85-130
What You'll Need
Socket wrench set with extension or combination wrench
Safety glasses
Baking soda and water
Wire brush or tooth brush
New battery

Just like any battery, car batteries eventually die. Fortunately, replacing a car battery isn't that difficult and as long as you didn't get stranded somewhere, the hardest part about this DIY skill is lifting out the old battery and putting in the new one. As for tools, you also don't need anything special for this task—just a socket wrench set or a combination wrench, a pair of gloves, and maybe a wire brush.

Once you're ready to install the new car battery, shut off the car's engine, pop the hood, and locate your battery. Now you're ready to grab your tools and put on some gloves to protect your hands from sulfate buildup. The only tools you'll need are a socket extension and ratchet and/or a combination wrench. The socket size will differ according to the vehicle, so bring your set to the car with you.

Step 1 - Detach Battery Cables

Starting with the negative (black) battery cable, loosen the nut holding it in place. You can use a combination wrench or the correct size socket with extension and ratchet to remove it. Once loosened, detach the negative cable by pulling it up and off. Next, do the same steps with the positive (red) battery cable.

If either cable is stuck or you had a hard time removing it, you can use a battery terminal puller to remove it. Using a screwdriver or other such tool to pry it off isn't recommended as you can damage the terminal or cable.

Step 2 - Remove Battery Hold Down Clamp

Using your combination wrench, you can now remove the battery hold-down clamp or other battery restraints your vehicle may have that are holding the battery in place.

Step 3 - Remove the Battery

A car battery being removed.

To remove the car's battery, use both hands to grab the battery from the battery tray as it will be heavy at around 40 pounds. If the battery has a handle, you can use that instead.

Step 4 - Remove Corrosion

A car battery with corrosion on it.

Before you replace the old car battery with a new one, you should clean up any corrosion that was left behind. This corrosion is usually seen as a cakey white residue, which is residue from the battery that may have built up around your battery's terminals. You can use a battery cleaning solution for heavy corrosion, or a mix of baking soda and water to make it into a paste. Use an old toothbrush or wire brush when cleaning the terminals and a rag on any other areas. Remember to clean the hold down clamp as well. Wipe down everything with a dry cloth when done. This step is a good one to do every time you change the oil or do other routine maintenance on your vehicle to ensure a good battery connection.

Step 5 - Install New Battery

A car mechanic placing a new battery into the engine.

Put the new battery into the battery tray and secure it in place again with the battery hold-down clamp. If you have any anti-corrosion battery terminal spray, use it now on both terminal ends. Make sure that the positive and negative terminals are on the right side.

Step 6 - Reattach Battery Cables

Reattach the battery cables. This time you will start with the positive (red) first. Attach and secure the positive cable and then do the same with the negative (black) battery cable. Doing it in this order is important so that you do not have any electrical issues.

Step 7 - Check Your Work

All you have to do now is a quick check of your work. First, make sure that all your cable connections and the battery clamp are nice and tight. Next, try moving the battery back and forth to make sure you don't have a weak electrical connection. Tighten up anything that moves.

Start your engine about a minute after install. If your car starts without any problems and lights are working, all is good. If you have any dim lights or flickering, shut the car off and recheck your battery terminal connections for tightness and corrosion and fix as needed.

Extra Tips

Be sure to pull any tabs on your new car battery that indicate the month or date of installation and then make note of that date in your calendar and vehicle maintenance records. Even better—set up an alert for a month or two before the battery is expected to be dead so that you won't get stranded in the future. Do a battery inspection after each oil change. Make sure the cables haven't loosened and check them for any battery acid corrosion and fix as needed.