Is your car battery covered in white, powdery corrosion? Not only is a corroded battery and connections unsightly, it can eventually hamper the delivery of voltage to the necessary parts of your vehicle. The first problem to develop with severe corrosion is usually the car having a difficult time starting, or not starting at all.

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A Corroded Car Battery

02-Corroded-Battery-Terminal (1024x576)Here, we are going to go through the procedure to clean the corrosion off your battery and battery terminals, and how to prevent the corrosion from developing in the future.

Tools and Supplies:

Step-By-Step Instructions for Cleaning a Corroded Car Battery

The following step-by-step instructions were written based on a Toyota Sienna. The general idea applies to most vehicles.

  1. Disconnect and remove the battery.
  2. Apply anti-corrosion battery cleaner spray to the corroded terminals.
  3. Rinse the battery off with water.
  4. Re-install the battery in the car.
  5. Clean the terminals with a terminal cleaner brush.
  6. Apply corrosion-resistant felt washers.
  7. Replace the battery terminals.
  8. Spray the terminals with corrosion prevention spray.
  9. Reinstall positive battery connector cover.

Alright, let’s get into the details. The following pictures show the above steps in detail.

Step 1: Disconnect and remove the Battery

Start by disconnecting the battery terminals. Do the negative terminal first. In this case, for a Toyota Sienna, a 10 mm socket was used.

After the negative terminal clamp is removed, then move on to the positive and remove that one as well.

Note: Don’t let your wrench touch both battery terminals simultaneously, or you may experience a shock.

Also, remove the battery holder, that is holding the battery in place. This used a 10 mm socket as well.

Now the battery should be free. Carefully lift it out of the vehicle. Be careful not to get the corrosive material on your clothing, or it may eat a hole in your shirt.

Step 2: Dowse the Corroded Areas with Battery Cleaner

For this step, you can either use battery cleaner spray, or a mixture of water and baking soda (e.g. 2 cups water to 2 tablespoons of baking soda).

14-Battery-Cleaner-Acid-Detector-Spray (1024x576)Take the spray or the home-brewed solution, and pour on or spray the corroded areas. For thick areas of corrosion, use an old toothbrush and scrub the region well. Use generous amounts, to neutralize the acid.

Make sure to get both battery terminal clamps, the battery terminals, and anywhere else where corrosion has built up.

Let the spray set for 2-3 minutes.

Step 3: Rinse off all the components with water.

Use a garden hose to rinse everything off with water. Get all of the spray or solution you made off.

Step 4: Put the Battery Back in the Car

Let everything dry out for a while, then carefully lift the battery back into the battery bay in the car.

Reconnect the battery holder with the 10mm wrench.

Step 5: Clean the terminals with a Terminal Cleaner Brush

Clean off the terminals with a Terminal Cleaner Brush. This will not only clean the posts, but also create a scored surface for a good connection to the car’s electrical system. This same cleaner brush has a removable handle with a separate brush to clean the inside of the clamp connector (for some reason they don’t show it in the picture on the product page, but it has one).

Step 6: Apply the Corrosion Resistant Felt Washers

Now take the corrosion resistant felt washers and put them onto the positive (red, +) and negative (black or green, -) terminals.

Step 7: Re-Attach the Battery Cables

After the corrosion resistant felt pads are installed, re-position the terminal cable clamps onto the battery terminals. Start with the positive (red) clamp; tighten it down.

Then move onto the negative (black) terminal and tighten that one down as well.

Make sure the clamps are tight, but don’t go overboard. You want them to be nice and snug, but stop before you get to the point where you are deforming the clamp.

Step 8: Spray the Terminals with Corrosion Preventative

Next, spray the terminals with corrosion preventative, or smear them with petroleum jelly. We want to create and oil-based protective layer on the terminals and clamps. Also, lightly spray any other areas where corrosion may occur.

Step 9: Replace the Positive Terminal Cover

If your vehicle has terminal covers, clip those back on over the battery terminals.

42-Replace-Positive-Terminal-Cover (1024x576)43-Cleaned-Battery-No-Corrosion (1024x576)

That’s it! Great work, and thanks for reading!

Tools and Supplies used:

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