How to clean car battery corrosion at home [With Pictures]

If you’ve got corrosion on your car battery, then it’s possible that you may have to replace the battery soon, as it’s not holding as much power as it used to. But before you go out and spend money on a new car battery, try cleaning the corrosion off of your current one.

It’s pretty simple, and in most cases can restore enough power to the battery to keep it running without replacing it. If you’re curious about how to clean car battery corrosion at home and keep your car running smoothly, here’s what you need to do!

How to clean car battery corrosion with Baking Soda

Cleaning car batteries doesn’t exactly top the list of favorite household chores, but maintaining your battery can help ensure your vehicle starts no matter what time of year it is.

Baking soda may seem like an unusual cleaning ingredient, but this compound actually has some surprising benefits as you learn how to clean car battery corrosion with baking soda in this easy do-it-yourself tutorial!

Materials Needed
  • Baking soda
  • Tooth brush
  • Petroleum Jelly
  • Socket Wrench

1. Disconnect the battery terminals

Park your car in a safe place, switch it off and open the hood and locate the battery. Then you can use a wrench to remove the terminals of the battery. To avoid any hazards, first remove the negative terminal (black terminal) and next remove the positive terminal (red terminal) of the battery.

Inspect both the battery and its wires for any signs of damage.

2. Apply Baking Soda and Water

You can use a paste made from mixing baking soda with water for this. Apply the paste on to the terminals with a tooth brush and scrub it until the white substance comes off completely. (You can also apply baking soda directly to the terminals and add water to achieve the same effect)

Alternatively you can use a commercial battery terminal cleaner like NOCO for this purpose. WD-40 which is a commonly found household item can also be used to remove corrosion.

The white corrosive substance in the battery terminals are made of either Lead Sulfate or Anhydrous Copper Sulfate. This anhydrous copper sulfate can turn blue when exposed to water vapor. Baking soda paste and battery terminal cleaners work by dissolving these substances.

3. Clean the terminals thoroughly

Use paper towels to clean the baking soda paste from battery terminals. Then you have to scrub the terminals of the battery and wires thoroughly and you can use a steel wool found in your home for this. Make sure no white color material is left behind.

There are specially made battery terminal cleaning brushes designed specifically for this purpose. If you’re interested, we can recommend LotFancy Brush.

4. Apply a battery terminal protector like Petroleum Jelly

In order to prevent corrosion in the future, you have to apply a battery terminal protector to the battery. Make sure the terminals of the battery are dry before applying. A good household option is petroleum jelly and you can apply it to both the terminals of the battery and wires.

There are commercial battery terminal protectors like NOCO if you don’t prefer petroleum jelly.

You can also use anti-corrosion washers to prevent future corrosion buildup by adding an extra layer of protection.

5. Reconnect the battery Terminals

Make sure the battery terminals are dry before reconnecting the wires. Connect the positive terminal (red terminal) first followed by the negative terminal (black terminal)

Step by Step Video

How to clean car battery corrosion with Coke

You can use this method to remove corrosion without using baking soda.

Materials needed
  • Bottle of Coca Cola
  • Tooth brush
  • Socket Wrench

Step 1 – Turn off Ignition

First step is to turn off the ignition and switch off all electronics inside the car. Then pop the hood and locate the battery of your car.

Step 2 – Remove the battery cables

Identify the positive and negative terminals of your battery and remove the negative (black color) terminal first using a socket wrench. Then remove the positive terminal (red color).

Step 3 – Pour Coke and brush

After removing the 2 battery terminal cables, take the bottle of coca cola and pour it onto the terminals and use a toothbrush to scrub the corrosion.

Sometimes corrosion build up will be so extensive you won’t be able to remove the terminals. In this case you can try pouring coca cola directly onto the battery terminals.

Step 4 – Dry the battery

Use paper towels to dry the terminals of the battery before reconnecting. Make sure you don’t spill coke to the engine and other parts of the car as it can cause harm. If there are any accidental coke spills to the other components of your car, use paper towels to remove coke spills promptly.

If you have petroleum jelly at home, its better to apply some to the terminals of the battery to prevent future corrosion. There are special corrosion preventing washers that also will help to prevent corrosion of the battery in the future.

Step 5 – Reconnect the terminals

Now its time to reconnect the cables to the battery. You have to connect the positive terminal first followed by the negative terminal to avoid possible electric shocks.

Causes of Car Battery Corrosion

The most common cause of battery terminal corrosion is the leakage of hydrogen gas from the battery or leakage of battery electrolyte. In addition to this the following will cause corrosion in your car’s battery.

Age of the battery

The lifetime of a car battery can vary substantially. However, if it has already passed four years, it is quite normal to see corrosion and a sign indicating its time to change the battery. Cleaning it won’t help as corrosion will continue to build with time.

Battery Overcharging

Overcharging a battery can cause its electrolytes and gases to expel to outside and come into contact with terminals and corrosion of the terminals.

Leaking of electrolytes

One of the commonest reasons that causes corrosion in a battery is the leakage of electrolytes. If a battery is not well maintained, electrolytes will leak and accumulate on the terminals, causing corrosion. If there are any cracks on the battery casing, this also can lead to leaking of electrolytes.

Filling too much distilled water (Battery Acid)

Having too much distilled water in a battery is another reason that causes corrosion. Since the terminals are made of metals that can corrode, if there is a lot of water, the excess will come out of the battery and corrode the terminals.

Troubleshooting the cause for car battery corrosion

Depending on which side corrosion forms, you can diagnose various battery problems. If it is on the negative terminal, this may be due to insufficient charge in the battery, while if it is on the positive terminal, it is likely due to an overload.

FAQs on Car battery corrosion

What is car battery corrosion?

Corrosion looks like a powdery, foamy substance, usually whitish in color, that forms around battery terminals. It is created due to the chemical reaction that occurs at the terminals and at the ends of the wire connecting the terminals forming Lead Sulfate and Anhydrous Copper Sulfate. 

When this happens, the battery cannot properly supply power to the various electrical systems in the car and can have various implications such as engine not starting, stalling while driving and malfunctioning of electrical equipment.

What are the causes for car battery corrosion?

The fundamental cause behind car battery corrosion is the leakage of chemicals and hydrogen gas from the battery that comes into contact with the terminals of the battery and the wires connecting to them.

These chemicals and hydrogen Gas will react with the battery terminals and wires to form Lead Sulfate and Copper Sulfate which appear as white substance around the battery terminals.

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