How To Clean Corrosion Off A Car Battery: A Step-By-Step Guide

Knowing how to clean corrosion off a car battery is an important skill that all car owners should learn. I learned the hard way. I noticed a buildup of a powdery material on one of my battery terminals one time I looked under the hood, but I ignored it, thinking it wasn’t a big deal. Soon enough, I had problems starting my car.

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It’s important to address battery corrosion as soon as you see it. Fortunately, it’s an easy task that anyone can do. While batteries need to be replaced eventually, cleaning and managing corrosion can help their life.

In this article, I’ll guide you through how to clean corrosion off a car battery step by step using the two most popular methods – using a homemade baking soda solution and using a car battery cleaner. Let’s also quickly go through how to clean electrical contacts using vinegar.

What Causes Car Battery Corrosion?

As you drive, your car battery simultaneously heats up and cools down, releasing hydrogen as part of the process. Corrosion occurs when hydrogen comes into contact with the surrounding material. It reacts with air, which then forms a corrosive environment, leading to powdery corrosion. Battery corrosion also has many different causes, which include:

• Age: Car batteries typically only have a lifespan. It’s normal to see corrosion if your battery is a few years old, or nearing the end of its lifespan.
• Overcharging: Overcharging your car battery can lead to really high temperatures, which may cause the electrolytes in your battery to expand. To avoid explosions, batteries have built-in vents for pressurized battery fluid to escape. However, when battery fluid leaks from these vents, it can cause corrosion.  
• Overfilling: Some batteries require to be refilled with water to work efficiently. Overfilling your battery causes excess water to come out through the vents. Corrosion begins when the water comes in contact with the battery terminals.
• Battery Damage: Battery damage is another common cause of battery corrosion. Battery acid can leak if your battery has cracks or any other damage to it. A leaking battery causes electrolyte buildup on the terminals, which increases the risk of corrosion.
• Copper Clamps: Battery leakages may also lead to the battery fluid coming in contact with its copper clamps, causing a chemical reaction that causes corrosion.

How To Remove Corrosion From Car Battery

I learned plenty of new skills this year. From removing oil stains from our driveway to getting rid of maggots in trash cans, I’m glad that I no longer have to call my husband for help when dealing with these not-so-exciting tasks at home. I also learned how to clean sneakers the proper way! Recently added to that list is how to clean corrosion off a car battery.

I discovered that a mixture of baking soda and hot water works best when dealing with car battery corrosion. I wasn’t surprised because, as someone who uses natural home cleaning methods as much as possible, I know how powerful baking soda is. It’s a staple in our home –  I use it to clean my stainless steel pans, my Whirlpool dishwasher, and my berber carpet, among other things.

I was delighted to find out that removing corrosion from a car battery is quick and easy.

What You’ll Need

• 4 tablespoons baking soda
• 1/4 cup warm water
• Wire brush
• Old toothbrush
• Clean rag or paper towel
• Protective gear (gloves and eye protection)
• Memory saver for car

You will need to disconnect your car battery if you’re cleaning it and its clamps. However, if you do so without a memory saver, your car might lose some of its custom settings like your gas mileage, current trip mileage, or radio, power seat, or window settings. It’s also important that you clean your car battery in a well-ventilated space, preferably outside in a garage or in your driveway. Here’s how to clean corrosion off a car battery step by step:

1. Create Your Baking Soda Mixture: In a bowl or cup, combine the baking soda and warm water to create a paste. 
2. Protect Yourself: Wear your gloves and eye protection (plain sunglasses would do). Make sure that you have good airflow around you.
3. Hook Up the Backup Power: Depending on the type of your memory saver, connect it directly to your battery or to your car’s OBD port. Make sure that it works before moving on to the next step – there should be indicator lights to show they are active.
4. Disconnect The Car Battery: Disconnect the car battery terminals, starting with the negative terminal (black) first, then the positive terminal (red).
5. Apply The Neutralizer: Using a toothbrush, apply the baking soda mixture over the entire area that’s affected by corrosion. Work the mixture into the big chunks first to neutralize them. Be careful not to get any of the mixture into the holes or vent caps on top of your battery.
6. Clean The Battery Posts and Terminals: Use the wire brush to scrub the battery posts and metal terminals clean, even without any corrosion.
7. Dry The Surface: When you’ve successfully removed any signs of corrosion, wipe down the surface of your entire battery with a clean rag. Dry thoroughly.
8. Reconnect The Battery:  Reattach the cables of your car battery in reverse order, connecting the positive (red) terminal first then the negative (black).

Using Battery Terminal Cleaner

There are plenty of products that can help you clean corrosion off a car battery. If you prefer to go with a store-bought battery corrosion cleaner, here’s how to use it.

What You’ll Need

• Battery corrosion cleaner
• Wire brush or scrub sponge
• Protective gear (gloves and eye protection)

1. Wear Protective Gear: Protection is important when cleaning a car battery, regardless of the type of cleaner you use. Wear thick rubber gloves and protective eyewear like sunglasses or goggles.
2. Disconnect The Battery: Same as above, plug in the memory saver before removing your battery’s connecting cables, disconnecting the negative (black) terminal first, then the positive (red).
3. Spray The Cleaner: Shake the can and spray the product on the battery until you’ve coated the entire affected area. Alternatively, you can also clean the car battery terminals using WD40.
4. Scrub Away: Scrub the affected area with a wire brush until any signs of corrosion are gone.
5. Reconnect The Battery: Reattach the battery cables in reverse order, the positive (red) terminal first then the negative (black).

Cleaning Electrical Contacts With Vinegar

Another effective way to clean your car’s battery terminals or other major electrical contacts is by using vinegar. Its acidic nature helps break down and dissolve corrosive materials. Here’s how to use vinegar to clean corrosion off a car battery:

What You’ll Need

• White vinegar
• An old toothbrush
• Cotton swabs
• Clean rag
• Damp clean cloth
• Protective gear (gloves and eye protection)

1. Wear Gloves and Glasses: Wear protective gloves and safety glasses to protect yourself from any accidental splashes or debris.
2. Disconnect The Battery: Again, connect the memory saver, then disconnect your battery’s connecting cables, working on the negative (black) terminal first, then the positive (red).
3. Prepare The Vinegar: Pour some white vinegar into a small container. Dip a cotton swab or small brush into the vinegar and gently apply it to the electrical contacts. If the affected area is large, use a rag soaked in vinegar. Allow the vinegar to sit for a few minutes to loosen any dirt or corrosion.
4. Scrub Away: After a few minutes, use a toothbrush to gently scrub the contacts and remove any buildup.
5. Wipe Clean: Wipe and dry the electrical contacts thoroughly using a clean cloth.
6. Reconnect The Battery: Reattach the cables in reverse order, the positive (red) terminal first then the negative (black).

Wrapping Up

Baking soda saves the day again! Once you’ve learned how to clean corrosion off a car battery, you’ll feel great! It’s awesome to be able to tackle a task that could help prolong the life of your car battery and prevent future corrosion, saving you money down the line.

If you learned something new from this article, share it with family, friends, and other car owners you know so they, too, can learn a cheap and effective way to clean corrosion off a car battery.