How to Change Your Car Battery

how to change car battery

If you have owned your car for more than three years and you are noticing that your headlights are dim or if you have needed a jump to get your car started after not running it for a few days, you may need a new battery.

Before you invest in a new car battery check the terminals to be sure that there is a good connection. If there is sulfate build-up (white or blue powder substance) surrounding the terminal hook up it just might need to be cleaned with a wire brush to re-establish a good connection. Be sure to wear protective gloves and goggles when cleaning the terminals because the sulfuric acid contained in the residue can burn your skin and eyes.

If the terminals are clean and making a good connection but your battery still seems weak, try running the car for 30 minutes to see if the battery takes a charge.

If neither of the above steps work you can bring your car to a local auto parts center to have the battery tested. If the battery tests good but the car doesn’t start, this is an indication of a faulty alternator, in which case you might want to let an automotive professional handle the repair.

If the car battery is dead you can purchase a new one from the same auto parts store that ran the test for you. While you do not have to purchase the same brand of battery as the one you are replacing, you do need to purchase the proper battery for your car’s make, model and engine size.

Now follow these steps for how to change your car battery:

Before changing your car battery – prepare properly.

  • Be sure to wear gloves and safety goggles when changing your battery because it contains a highly corrosive, highly flammable solution.
  • Do not smoke while changing your battery because the solution contained in the battery is highly flammable.
  • Make sure that your car is parked on a flat, level surface and that the parking brake is on before you open the hood.
  • If your car is a newer model with lots of electronic amenities, you will want to consult your owner manual before disconnecting the terminals because once you do, all your systems will be erased (this may have already occurred if your car was dead and needed a jump). The owner manual will tell you how to reset your systems.
  • Make sure your car is turned completely off before attempting to change the battery. Take the key out of the ignition to be sure.

What you will need to change your car battery:

  • 8mm-10mm wrench
  • Flat Head Screwdriver
  • Wire brush
  • Baking soda and water solution (two tablespoons of baking soda to a cup of water in a disposable container)
  • Masking tape
  • Felt tip marker
  • Microfiber towel
  • Lithium grease

Identify your car battery terminals correctly.

The positive terminal is usually red and has a plus sign and the negative terminal is usually black and has a minus sign. It is important that you identify your terminals/cables and disconnect/reconnect them in the proper order because mixing them up can damage your car’s electrical system.

How to change your car battery.

  1. Using your wrench, loosen the negative cable clamp and disconnect it from the terminal.
  2. Take a piece of masking tape and wrap it around the cable then mark it as the negative cable using the felt tip marker.
  3. Next, disconnect the positive terminal and label it positive.
  4. Using your screwdriver, unfasten the battery holder, removing any screws, clamps or bars holding the battery in place.
  5. Lift the old battery out of the car.
  6. Dip the wire brush into the baking soda solution and clean any residue from the terminal clamps. If the clamps are severely corroded or damaged they may need to be replaced by a mechanic. If they are still in good shape dry the clamps thoroughly before connecting them to the terminals.
  7. Slide the new battery into place.
  8. Reconnect all the screws, clamps or bars that hold the battery in place.
  9. Reconnect the positive terminal first, tighten the clamp with your wrench and remove tape.
  10. Reconnect the negative terminal, tighten the clamp with your wrench and remove tape.
  11. Spray the terminals with lithium grease to prevent corrosion.
  12. Make sure that all your tools are accounted for before closing the hood firmly and starting your car.
  13. Reset all electronic devices as directed in your owner manual.
  14. Properly dispose of old battery by bringing it back to your auto parts store for recycling. Car batteries cannot be disposed of with household trash.