How to Replace a Car Battery
Duration: 10-30 minutes
How often: Every 3-5 years
Replacing a car battery is a relatively easy job that can be accomplished with only a few tools. However, some vehicles' car batteries are located in tough-to-service areas such as under the front fender, under the rear seat or in the trunk. If this is the case, consider having the car battery changed at your local NAPA Auto Care center.
Your car battery supplies the electrical current necessary to start the engine. It also provides necessary power to the electrical components and accessories even when the vehicle's engine isn't running. The car battery also acts as a voltage stabilizer for the whole electrical system.
Things you'll need from your garage or your local NAPA Auto Parts store:
- A new replacement battery
- Battery terminal cleaning brush
- Hand tools to remove the battery terminals and hold-down
- OBDII memory saver (optional, recommended for late-model cars)
Step 1 – Buy a replacement battery for your car.
You must know the make and model of your car to make the correct purchase. It also helps to know your battery's BCI number. Car batteries come in different sizes, construction types, CCA (cold cranking amps) and amp-hour ratings. You want the replacement battery to match the original battery as closely as possible.
Step 2 – Locate the battery, typically under the hood.
Identify the positive and negative terminals. Positive terminals are labeled with a "+" or color-coded red. Negative terminals are labeled with a "-" or color-coded black. Loosen the bolt that holds the negative terminal and remove the negative cable first. Next, remove the positive cable.
Step 3 – Unscrew the battery hold down clamp.
Lift the battery and remove it from the car. Inspect the battery terminal clamps. Clean or replace them if necessary.
Step 4 – Clean the battery tray.
Use plenty of fresh water or a mixture of baking soda and water. Wait for the terminal clamps and the battery tray to dry before installing the new battery.
Step 5 – Clean all corrosion from your battery.
Corrosion can be cleaned off using a stiff brush and a baking soda/water solution. After removing the corrosion, rinse off the battery with water. Clean the battery tray by wiping it out with moist paper towels and mild detergent. NAPA Auto Parts stores carry anti-corrosive battery spray. Use this to prevent future corrosion.
Step 6 – Place the new battery into the battery tray.
Make sure the positive and negative terminals are on the correct sides, and then install the battery hold-down. Reattach and tighten the positive cable first before reattaching the negative cable.
Step 7 – Start your car.
Verify that the installation is complete and the cables are securely attached to the battery posts. Gather your tools and close the hood of your car securely.
Step 8 – Dispose of the old battery properly.
Car batteries contain highly toxic material and cannot be thrown out with your garbage. You can dispose car batteries at your nearest NAPA Auto Parts store or NAPA Auto Care center.
- Wear gloves whenever working with batteries and follow all safety precautions listed in your owner's manual.
- You'll need to know the year, make, model and, in some cases, engine type of your car when you buy supplies. If you use our NAPA Know How App, you can scan your VIN so you'll always have the information you need.
- Your battery and charging system or alternator should be inspected at least once a year at your local NAPA Auto Care center.
- Neutralize any electrolyte spills or corrosion with a solution of baking soda and water.
- Always remove the negative terminal first.
- Protect your eyes with safety glasses when changing a car battery.
- Never touch a metal tool across the battery terminals, or from the positive post to any other metal on the car. This will help prevent large sparks and damage.
- Extinguish all smoking materials and open flames. Be cautious about creating any electrical sparks around the battery.