Buzz
A car battery will eventually stop working, even with proper maintenance. If your headlights are dim or the vehicle has trouble starting, it might be due to a dead battery or one that’s been in use for over 3 years. At this point, it’s time for a replacement. Fortunately, replacing a battery is a simple task that can be done with just a few basic tools.
Steps
Remove the old battery
Park the car on a flat surface and turn off the engine. Avoid replacing the battery on the roadside if possible. Find a safe location, away from traffic, sparks, open flames, or water. Engage the parking brake and turn off the car. Remove the key from the ignition to ensure there’s no power flowing into the battery.
- A garage or driveway is a safe place to replace the battery. Ensure the area is well-ventilated (open the garage door).
Tip: Disconnecting the battery will reset the clock, radio, navigation system, and alarm settings, so be sure to have the alarm code on hand before starting. If you don’t remember it, refer to your user manual.
Wear protective gear and open the hood. The car battery contains sulfuric acid electrolyte, a corrosive substance that can burn skin and release highly flammable hydrogen gas. It's essential to wear insulated gloves and safety goggles for protection. Open the hood and prop it up with a hood support rod if necessary.
- Remove any metal jewelry, like watches or rings, to avoid electric shock.
- Wear old clothes to prevent oil stains.
Locate the battery. The car battery is usually positioned in one corner of the engine compartment, near the windshield or front bumper, either on the left or right side. Look for the rectangular battery box with two cables attached. In newer vehicles, the battery may be under a plastic cover, so you'll need to remove the cover if applicable.
- Consult your user manual if you're having trouble locating the battery.
- Note that in some cars, the battery is located in the trunk rather than under the hood.
First, disconnect the negative cable and secure it in place. Always disconnect the negative cable first to avoid short-circuiting. The negative terminal is usually marked with a black color and a minus (-) symbol nearby. Remove any plastic cover if present, then loosen the negative cable clamp with a wrench and pull the cable off the terminal.
- Use a tie to secure the negative cable in the engine compartment, ensuring it doesn’t come into contact with any metal parts.
- Depending on your vehicle, you might need a 7mm, 8mm, 10mm, or 13mm wrench to remove the cable. However, if the battery terminal has a quick-release clamp, you won’t need any tools.
Next, disconnect the positive cable and secure it in place. The positive terminal is usually red and marked with a plus (+) symbol. Remove any plastic cover if present, then loosen the positive cable clamp with a wrench and pull the cable off the terminal. Secure the cable in the engine compartment.
Warning: Ensure the negative and positive cables do not touch each other and avoid them coming into contact with any metal objects, as this could cause a dangerous short circuit.
Remove the battery. Inspect the battery hold-down bracket and remove all screws connecting the battery to the bracket. You may need a wrench with the proper size socket and an extension bar. Once the screws are removed, lift the battery out of the engine bay and set it aside on a concrete surface.
- The battery typically weighs around 10kg, so consider asking someone for assistance if you’re unable to lift it on your own.
Install the new battery
Clean any corrosion on the battery terminals. Check for any white, green, blue, gray, or white powdery residue on the terminals. Use sandpaper or a 100-grit abrasive cloth to clean the corrosion off the terminals.
- Remember, the acid in the battery is corrosive, so avoid letting it come into contact with your skin or clothing.
Purchase the correct replacement battery. Take a photo or note down the information on the old battery, such as size, type, and model number. Go to an auto parts store and provide this information to the salesperson, along with the year, make, model, and engine size of your car. They will help you find the right battery.
- Car batteries come in various sizes and power ratings, so make sure you buy the one that fits your vehicle.
- If you're in the U.S., consider bringing the old battery to the store. Some auto parts stores allow you to trade in your old battery, so you don’t have to pay for recyclable parts.
- If the store doesn’t accept old batteries, take it to a recycling center for disposal. Do not throw it in the trash, as the battery contains corrosive materials.
Secure the new battery into the bracket and lubricate the terminals. Place the new battery into its bracket and tighten the securing bolts. To remove the battery, simply reverse the steps. After securing it, apply a thin layer of lithium grease to each terminal to prevent corrosion.
- Ensure the new battery is installed in the same orientation as the old one.
- Make sure all bolts on the bracket are tightly secured to prevent the battery from shaking or shifting while driving.
- Avoid spraying lithium grease on any other engine components aside from the positive and negative terminals.
Connect the positive cable first. Carefully detach the positive cable, which is tied in the engine compartment, being careful not to let the cable touch any metal parts. Place the cable on the positive terminal and tighten it with a wrench. If the battery has a cover, close it after securing the terminal.
Warning: When reconnecting the battery, always connect the positive terminal before the negative to avoid accidentally completing the circuit before everything is properly connected.
Now, connect the negative cable. Repeat the same process by removing the tie from the negative cable and attaching it to the negative terminal. Tighten the clamp with a wrench and ensure that neither the wrench nor the cable comes into contact with any metal objects, as this could cause a dangerous spark.
- If the battery has a plastic cover, make sure to replace it once the cable is secured.
Close the hood and start the vehicle. Remember to remove all tools from the engine compartment and securely close the hood. If everything is done correctly and the battery was the issue, the vehicle should start up normally. Enter the alarm code if necessary.
- Check that all electronic devices are functioning correctly, and then reset the clock, radio, and navigation system.
Advice
- Wear old clothes to avoid worrying about stains.
- In some vehicles, the battery is located in the storage compartment rather than under the hood.
- Some larger vehicles have multiple batteries, which may be placed in different locations.
Warning
- Never let the battery lie on its side or upside down.
- Avoid working in damp conditions.
- Do not place metal objects on the battery, as the two terminals could connect and cause a short circuit.
- Remove any metal jewelry before replacing the battery.
- Wear insulated gloves and safety goggles.
- Never connect the two battery terminals together.
Things You Will Need
- Insulated gloves
- Safety goggles
- 7-mm, 8-mm, 10-mm, or 13-mm wrenches
- Cable ties
- Socket wrench
- Extension bar
- 100-grit sandpaper or abrasive cloth
- New battery
- Lithium grease
