How to Clean Battery Acid Safely

Corroded Battery

smartstock / Getty Images

Overview
  • Working Time: 10 - 20 mins
  • Total Time: 1 - 2 hrs
  • Skill Level: Beginner
  • Estimated Cost: $5 to $10

It's that dreaded moment when you open the battery compartment door of your electronic device and find battery acid leakage. Should you feel bad for letting an expensive device potentially be ruined by a mere battery? 

Not at all. With today’s numerous devices depending on batteries, acid leakage and corrosion are common. There are simple ways to neutralize the battery acid and to remove the corrosion, leaving the battery compartment in like-new condition so that your device works again. Plus, there are simple ways to prevent batteries from leaking acid into your device again.

What Is Battery Acid Leakage?

Battery acid is an alkaline residue composed of potassium hydroxide. While it’s not a true acid, it’s no less corrosive or hazardous. It can burn your skin, harm your eyes, and corrode the delicate wires and chips in battery-powered devices.

You’ll only find this type of battery acid leakage with alkaline batteries. Devices increasingly are using lithium-ion batteries, and these batteries fail in a completely different way. While alkaline batteries emit a fluid that eventually turns into a white powdery crust, lithium-ion batteries abruptly stop working or they heat up, catch fire, or in rare cases, they explode.

Products For Cleaning Battery Acid

To clean battery acid, you first need to neutralize it with a mild acid. Ordinary white vinegar—the type found in the kitchen—is the best product to begin with. Vinegar is green, inexpensive, clear, and will not leave a sticky residue.

Lemon juice is another mild acid that you can use for neutralizing battery acid, though it does leave a sticky residue. Juice from a real lemon that has been strained of pulp and seeds is best, as bottles of reconstituted lemon juice are diluted with filtered water.

Safety Considerations

  • Wear safety glasses and latex gloves.
  • Clean and neutralize all of the wet battery acid before scraping away the white corrosion.
  • Dispose of the leaking batteries in a community-approved manner, not in the regular trash.
  • Do not use baking powder to clean battery acid. This can form a conductive paste that can create an electric short and ruin your device

What You'll Need

Equipment / Tools

  • Cotton swabs
  • Cotton balls or cloth rags
  • Fine-grit sandpaper
  • Paper clip
  • Old toothbrush
  • Pencil eraser
  • Clean glass container
  • Safety glasses
  • Latex gloves or latex-substitute such as nitrile

Materials

  • Household white vinegar
  • Lemon
  • Scrap cardboard

Instructions

  1. Protect the Work Surface

    Lay a sheet of scrap cardboard across the table to protect it. Make sure that you are wearing your protective gear, including safety glasses and gloves.

  2. Remove and Dispose of the Old Battery

    Remove the corroded battery from the device. If the battery is stuck, gently pry it out with an old butter knife or screwdriver. For a cylindrical battery that is stuck, try to rotate the battery to loosen the corrosion.

  3. Neutralize the Battery Acid

    Pour the neutralizing liquid into the glass container. Dip the cotton swab or ball into the vinegar or lemon and squeeze it out to prevent excess liquid from entering and damaging your device. Daub the neutralizer around the battery compartment and any areas that have acid. Frequently change out the cotton swab for a new one. 

    Note

    When the neutralizer comes into contact with the battery acid, it may fizz. This is normal. When the fizzing stops, the battery acid has been neutralized.

  4. Neutralize Tougher Battery Acid

    For particularly stubborn battery acid, dip an old toothbrush in the cleaner. Since this can transfer more liquid to the device, be very careful. Have clean towels nearby to mop up spills.

  5. Scrape Out the Corrosion

    Let the device dry for about an hour. Scrape out the white corrosion with the paper clip or fine-grit sandpaper in the #220 to #320 range. Be gentle when doing so to avoid damaging the thin metal terminals. Tap out the debris. Do not use water to clean out the debris.

  6. Polish the Terminals

    Use the pencil eraser to polish the metal battery terminals to a shine. Any remaining corrosion will limit electric conductivity, so make sure that the terminals are completely clean.

Prevent Battery Acid Leakage in Your Devices

  • Make sure that the batteries are properly installed. Reverse installation can damage the battery and can lead to leakage.
  • Remove the batteries when the device isn’t being used for a long time.
  • Don’t store the batteries in a refrigerator or freezer, but do keep them in a cool, dry location that's away from direct sunlight.
  • Avoid mixing new and old batteries in the same device.
  • When storing multiple batteries, use a rubber band to bundle the batteries and prevent the battery terminals from touching.