How to Clean Battery Terminals?- A 5 Simple Steps

Have trouble starting your car or other issues with its performance and noticed a flaky white or blue-ish substance on your car battery? Your problem is battery corrosion. But worry no more, as this article will guide you on how to clean car battery corrosion.

You can actually get rid of corrosion on a car battery very easily. Just carefully disconnect the cables, apply your cleaning solution, scrub off the corrosion, rinse, dry the battery, apply a corrosion preventive substance, then reconnect the cables.

What Is Battery Corrosion?

Corrosion on your car’s battery can be incredibly easy to identify, which is probably why you’re here. Typically, the corrosion is white in appearance, one only could describe as “crusty.” It may turn a blue or greenish color when exposed to moisture.

The corrosion takes over the battery’s terminal and reduces the connection due to corrosion remaining a terrible conductor of electricity. The power is then thrown into a transient current flow, returning to the battery.

The corrosion can be caused by a variety of things due to hydrogen gas being released from the sulfuric acid inside the battery. As the gasses react to the atmosphere in the battery, it begins to produce a corrosive environment leading to battery fluid leakage. When the likes of salt or moisture are thrown into the equation, the process of corrosion will pick up speed.

Some reasons for battery corrosion include:

  • Overcharged – if the battery is overcharged, the fluid can expand and escape through overflow holes. Once this acid touches the terminal, corrosion begins. If this occurs, simply clean away the corrosion regularly to ensure reliability.
  • Gas escape – in every battery, there are tiny vents the hydrogen gas escapes. If these gases come in contact with your battery’s terminals or car’s cables, corrosion can occur. This depends on the placement of the vents and how much gas escapes through them.
  • Age – if your battery is older than five years, you should accept it’s probably on its way out. When batteries get old, corrosion is merely a side effect and not much can be done. Even if you clean it and it begins to work, you should probably have it replaced with a new battery as soon as possible.

How To Clean Battery Terminals?

Now you’ve determined your cause, let’s get to business. This simple process involves battery acid, so you must be taking the proper precautions needed to protect yourself. This includes wearing the proper rubber gloves and eye protection.

Here is what you need to clean your battery:

  • Baking Soda
  • Petroleum Jelly
  • Anti-Corrosion Pads
  • Stiff-Bristle Brush, Wire Brush, Or Professional Tool
  • Water
  • Protective Gear
  • Shop Towels

Once you’ve gathered, your materials, you’re ready to begin. Pop your hood and follow these simple steps:

Related Post :-  How to Dispose a Car Batteries the Right Way?

Step 1: Ensure That Your Car Had Been Turned Off

Your car has to be turned off before cleaning the car battery. This step should be done for safety since you’re going to touch the battery. It also prevents the accidental grounding of cables.

Step 2: Remove the Cables, Working on the Negative One First

To be able to thoroughly clean the corrosion off of a car battery, you would need to remove the cables first with a wrench. But you must first identify the negative and positive terminals from where you are going to disconnect cables. For safety, the negative cable should be disconnected first to avoid electrocution and burns.

The negative terminal can usually be identified by a marking of the negative sign, the abbreviation “NEG” written on it, and/or the color black. The positive terminal comes with a marking of the positive sign, the abbreviation “POS” written on it, and/or the color red.

Also, while you disconnect the negative cable, you must try not to let the wrench contact the positive terminal. You might get shocked if they touch. Then move on to the positive cable after disconnecting the negative cable.

But if you are having a hard time removing any of the cables, try to twist the cable while pulling it up.

Step 3: Check the Car Battery for Any Damages

If you observed any warping, bulging, dents, or cracks where acid is leaking, that is a sign that the battery is damaged. If so, you would have to replace it.

Step 4: Check the Car Battery Cables and Clamps for Any Damage

If you observed that any of the cables’ insulation has been torn, frayed, splintered, peeled, dried, cracked, or corroded, that is a sign that they are damaged. Damaged car battery cables are usually the cause of a non-starting engine. If you find any of those signs of damage on any of your car’s battery cables, you will have to replace them.

Step 5: Clean off the Corrosion with a Cleaning Agent or Baking Soda With Hot Water

Using around a teaspoon of baking soda, or more as necessary, coat your battery terminals and other affected areas. Pour a small amount of water on each terminal then use your brush to scrub the corrosion away. While a steel wire brush will work the best, an old toothbrush can work with enough elbow grease.

Alternatively, you can also combine the water and baking soda in a cup to create a cleaning solution. Dip your brush in it and scrub away! You can repeat the same cleaning process to clear away any corrosion found on the end of your battery cables.

Either way, you go about cleaning the terminals, and you’ll notice the baking soda react with the corrosion, neutralizing the acidic nature and making it safe to handle. Once the corrosion has been removed, rinse it away with clean water.

Related Post :-  What is An Alternator In a Car And How Does It Work?

When dealing with battery corrosion, you can either go for a battery cleaning agent or baking soda plus hot water. Just find and follow the steps for whatever method you choose below.

Method #1 – Using a Battery Cleaning Agent

On the corrosion found on the battery, terminals, and cable, apply the cleaning agent. Be careful not to let the cleaning agent touch the car’s paint, as some cleaning agents can create a permanent stain.

Let the cleaning agent soak on the corrosion for a few minutes. Then scrub out the corrosion with a toothbrush or battery terminal cleaner brush.

Method #2 – Using Baking Soda with Very Hot Water

Baking soda & hot water cleaning solution can be applied in three ways:

  • You can create a battery cleaning solution by mixing a tablespoon of baking soda and a cup of very hot water. Then you would dip the toothbrush into the solution. Using the toothbrush, scrub off all the corrosion from the battery.
  • Or after creating the solution, you can apply it by directly pouring a small amount on the corroded areas and scrubbing away with a toothbrush or battery terminal cleaner brush.
  • You can also pour and coat baking soda on the areas with corrosion. Then you would pour the water slowly on the battery. Afterward, scrub off the corrosion with a toothbrush or battery terminal cleaner brush.

Additional tip: If your battery clamps are corroded, you can let them soak in your baking soda solution for a few minutes. Thereafter, scrub them. Repeat if necessary.

Step 6: Rinse the Car Battery and Cables

Using cool water, rinse the car battery and cable ends. Make sure that all the corrosion and cleaning solutions are completely washed away.

Step 7: Dry the Battery

Water getting in contact with electric components can be hazardous. So you have to make sure that the battery, battery terminals, and battery clamps are totally dry before reconnecting the cables.

Dry them all off with either a towel or cloth. Or if possible, you can speed up the drying with the use of an air compressor.

Step 8: Apply Petroleum Jelly, Terminal Protection Spray, or Anti-Corrosion Pads

Prevent your car battery from being corroded in the future by applying a generous coat of petroleum jelly or battery terminal protection spray on the terminals, posts, and clamps. You can also use anti-corrosion pads coated with a corrosion preventive compound.

Step 9: Reconnect the Cables, Starting with the Positive Cable

As opposed to the process of disconnecting cables, in reconnecting cables, you should start with the positive cable to avoid getting injured. Afterward, move on to reconnecting the negative cable. Use the wrench to tighten the cables.

Related Post :-  7 Signs Of a Bad Alternator | Faulty Alternator Symptoms

Again, be careful where the wrench is moving. Once the cables are reconnected, test if they are tightly attached by twisting them by hand.

Related Article:

Take Safety Precautions

The potassium hydroxide that leaks from batteries are a corrosive material that is highly toxic. The caustic material can cause skin irritation and damage your eyes. It can also cause respiratory problems.

Always take the following precautions when cleaning batteries.

  • Avoid contact with your skin. Make sure to wear rubber or latex gloves.
  • Keep your eyes safe by wearing safety glasses.
  • Make sure the area is well ventilated.
  • If the potassium hydroxide makes contact with your skin, flush the area well with water.

Keeping your car battery clean can help get things moving when your car won’t start and the battery flow is weak. Staying on top of your battery’s charge is crucial to avoid getting stranded.


How to Clean Battery Terminals?

Using around a teaspoon of baking soda, or more as necessary, coat your battery terminals and other affected areas. Pour a small amount of water on each terminal then use your brush to scrub the corrosion away. While a steel wire brush will work the best, an old toothbrush can work with enough elbow grease.

How do you clean the corrosion on dirty battery terminals?

You can purchase a battery terminal cleaner from your local auto parts store, but a regular old toothbrush will work just fine. You’ll also need a container of baking soda, mixed with water until it becomes a paste. This will work to neutralize the acidic corrosion on the battery terminals.

Will WD 40 clean battery terminals?

Some people use WD-40 to clean their car terminals. This can work well but will require more elbow grease. To use this method, make sure your terminals are disconnected. Then you’ll spray WD-40 on each of the battery terminals and the cable connections if they’re also covered in grime.

How do you clean acid off car battery terminals?

Thoroughly mix a tablespoon of baking soda with a cup of hot water. With an old toothbrush, dip you brush into this solution and scrub at the corrosion. If the corrosion is too hard to remove, consider buying a battery terminal cleaner brush. Completely dry the battery.

Can you clean battery corrosion while connected?

Without the current, you can work safely even when your battery terminals are connected. However, you should not risk your safety, and it is best to disconnect the terminals when you clean your battery.

1 thought on “How to Clean Battery Terminals?- A 5 Simple Steps”

  1. Thank for your article. I have trouble starting my car or other issues with its performance and noticed a flaky white or blue-ish substance on my car battery? Your article helps me a lot.


Leave a Comment