Close up of corrosion on a car battery

How to Safely Clean Corrosion Off a Car Battery Terminal

What to Do to Clean Corrosion Off a Car Battery

Is your vehicle having a hard time starting up? Are your headlights dim? Chances are, you have a battery problem on your hands. When you open the hood to look at it, check for a flaky white or blue substance on your car battery. This substance, called corrosion, will form on the battery terminals over time due to the chemical structure of the battery. While a little likely won’t do any harm, a lot can block the electric current and cause headaches for drivers. Of course, it’s dangerous to try to clean corrosion without knowing how to safely. If you are uncomfortable with removing the corrosion yourself, visit your local mechanic for help. Otherwise, follow our step by step guide below on how to safely clean corrosion off a car battery terminal.

[ READ MORE: Signs of a Failing Car Battery ]

Step by Step Guide on Removing Corrosion from a Car Battery Safely

  1. Turn off the engine. This is for your safety. If your engine was running for a while, wait for it to cool before popping the hood.
  2. Disconnect the battery with the negative terminal first. Use a wrench to disconnect the negative terminal and avoid letting the wrench come into contact with the positive side as it may shock you. Do the same for the positive terminal.
  3. Check for damage to the battery. If you notice any cracks, dents, or warping with your battery, cleaning the corrosion may not do you any good. It’s time to shop for a replacement.
  4. Thoroughly mix a tablespoon of baking soda with a cup of hot water. With an old toothbrush, dip you brush into this solution and scrub at the corrosion. If the corrosion is too hard to remove, consider buying a battery terminal cleaner brush.
  5. Completely dry the battery. Water and electricity don’t mix well, so make sure the battery and its terminals are completely dry before reassembling it.
  6. Replace the clamps starting with the positive terminal. This step is the opposite of step 2. Start with the positive side then move to the negative. Don’t forget to watch where your wrench is moving.
  7. Start up your vehicle and make sure it starts up normally. If not, you will need to buy a replacement. If it does start up fine, consider getting your battery tested. Chances are, if it built up a bunch of corrosion, it is starting to get old and you should be aware of how long your battery may continue to last.

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Close up of a car battery