Informational Guide

How To Clean Car Battery Corrosion?

Learn how to clean a car battery with this complete guide. Get corrosion off your batteries with these various methods for cleaning and maintaining.

The car battery is vital to starting and operating your vehicle. As it gets used, corrosion starts to build up around the connectors, which can inhibit the performance.

To keep the battery running its best and provide longevity, you want to know how to clean car battery corrosion. We will walk through the steps of how to clean a car battery.

Battery corrosion occurs when the hydrogen gas is released from the sulfuric acid located inside the battery. If this corrosion only occurs on the negative terminal, it could indicate an undercharging condition, which needs to be corrected. Otherwise, you want to know how to clean corrosion off the car battery.

Problems With Car Battery Corrosion

You may notice white, green, or blue gunk building up on the battery terminals. This corrosion could interfere with the connection, causing trouble when you attempt to start the vehicle.

Not only will you notice difficulty starting, but you might also hear a rapid clicking or slow cranking noises as you turn the key.

How To Clean Corroded Battery Terminals

To learn how to clean the battery terminals on a car, you want to start by preparing your tools and materials. Safety should be your top priority.

Tools List:

Step 1: Determine the terminal configuration of your battery & Turn car off

Inspect the battery to determine how you are going to disconnect it. Always turn the car off before proceeding with the cleaning process.

Step 2: Remove Battery Cables

Unfasten the cable from the negative side first. Then, remove the positive cable next. Ensure that the two cables never touch one another.

Step 3: Inspect Battery Cables

Look for cracks or wear to the battery cables. If there is any indication that the battery cables are worn, you want to replace them at this time.

Step 4: Remove And Neutralize Battery Corrosion

Using a mixture of baking soda and water, spread the solution onto the corrosion with a toothbrush and let it sit for a few minutes. You can scrub the tough areas gently.

Step 5: Dry And Polish Battery Posts And Battery Terminals

Spray down the solution with your water and gently dry it off with a microfiber cloth. Spread a small amount of petroleum jelly on the clean connectors.

Step 6: Reconnect Battery Cables

Working backward from the removal, you will now reconnect your battery cables carefully. Again, make sure these never touch one another.

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Alternate Methods For Removing Car Battery Corrosion

As you evaluate how to clean battery corrosion on a car, there are three main cleaning agents that are most effective.

Cleaning with Baking Soda

We discussed this method in-depth above and find this to be one of the quickest, most effective ways to remove battery corrosion. It also doesn’t take any skill or specialized equipment. Most people have the tools needed at home.

Cleaning with Coke

If you want to know how to clean car battery corrosion without baking soda, consider using Coke. When you figure out how to clean a car battery with Coke, you will follow the same basic principles above, but this time by pouring soda on the corrosion.

Cleaning with Vinegar

You can also learn how to clean terminals on a car battery with vinegar. Simply pour some white vinegar into a bowl and use a cotton swab to apply it to the connectors. Again, make sure the vinegar is thoroughly cleaned off before attaching the connectors. 

How To Prevent Further Car Battery Corrosion

After you follow the steps on how to clean car battery acid corrosion, you want to prevent it from happening again.

Dielectric Grease

This automotive grease protects electrical connections from dirt, grime and corrosion. You apply it to the battery terminals in a small amount to ensure longevity. It’s also valuable to have on hand for other applications with your vehicle or on your watercraft.

Petroleum Jelly

Petroleum jelly is also beneficial in keeping moisture off of metal and connectors. By applying a small amount to the battery terminals before reconnecting, you ensure protection and keep the corrosion from coming back again. This jelly is also beneficial on any metal surface that requires protection.

Anti-Corrosion Washers

These washers resemble felt pads that have a chemical composition to prevent corrosion. To install these, you would remove the battery cables, place the washers on the terminals, and then reconnect the cables. You wouldn't want to use these in conjunction with the jelly or grease listed above. 


People Also Ask (FAQs)

Can you clean battery terminals while connected?

Any time that you work on your car battery, you should always disconnect the cables. In addition, you can further safeguard the operation by keeping the car turned off.

How do you clean up battery acid from a car battery?

We have showed you how to clean up car battery corrosion with baking soda, soda, and vinegar. All of these options are simple to do and require minimal equipment. 

Can battery corrosion keep a car from starting?

Yes. If the connection isn’t strong, you might have trouble getting the vehicle started.

Can you spray WD40 on car battery terminals?

WD40 can be used on your battery terminals to clean them off. It’s also a reputable product to use on a multitude of other objects.

Is battery corrosion harmful to the skin?

The chemical leaking from batteries is corrosive and toxic. This caustic material can damage your eyes and cause skin irritation, which is why you should always wear safety glasses and gloves when cleaning the battery.

How do I tell positive and negative on a battery if the battery posts are not marked?

The positive post is marked with a + sign or has colored plastic covering that is red. In addition, the negative terminal will have a – sign or will feature a black cover.


Now you know how to clean car battery terminal corrosion and why it is important. You want to take care of your automotive battery, so it takes care of you and charges properly. Keep it clean and prevent further corrosion to ensure longevity.