What Is Blue Stuff On Car Battery? – How To Clean Up Blue Stuff On The Battery

The humid climate quickly leads to oxidation and corrosion of the batteries. This manifests in the blue stuff on car battery terminals as blue chalk dust collects around the two terminals.

If you’ve encountered the above-corroded battery terminals and are looking for ways to clean them, take a few minutes to read through the information outlined in the following article.

What Is Blue Stuff On Car Battery?

Blue Stuff On Car Battery

My car battery has blue stuff on it!” is the exclamation of many drivers when they are afraid that the blue active substance attached to the car battery can harm or reduce the life of their car.

So, What is blue stuff on a car battery?

The blue stuff on battery terminal can be copper sulfate or lead sulfate, a type of corrosion caused by the chemical reaction of the battery’s substances and electric current or the oxidation of two batteries in humid weather.

The most corroded battery location is usually the blue stuff on negative battery terminal or the corresponding battery connectors.

When corrosion occurs at these locations, it can lead to many other serious failures related to vehicle operation issues when not corrected early and promptly.

Many people often think fixing this problem is tricky and dangerous, but that is not the case.

You can completely fix them through a few simple steps that will be explained more clearly in the content below.

The Cause Of Blue Residue On Car Battery

To answer the question, “Why is there blue stuff on my car battery?” we think there are 3 main reasons for this blue stuff on the car to appear:

1, The Exhaust Of Hydrogen Gas Inside The Battery.

The most common blue corrosion that most car battery users experience is the type of corrosion that occurs during the regular release of hydrogen inside the battery.

Hydrogen gas is produced when the acid in the battery heats up and then cools, and at the same time, this gas is also released.

They are usually found through the vents on the car battery case. However, this hydrogen gas can react with the lead in the battery terminals and create a chemical reaction.

2, The Chemical Reaction Between The Clamps And The Terminals.

Another type of blue battery corrosion is said to arise from a reaction between the copper terminal clamps and terminals.

This type of corrosion usually only occurs when the battery terminals are experiencing high humidity.

You can detect these problem substances by accumulating blue corrosive at the site of the contact reaction.

3, The Sulfation Reaction Of The Battery.

The final type of battery corrosion occurs during a process known as battery sulfation.

All automotive batteries include sulfuric acid, an active element that can crystallize with time, particularly in batteries that aren’t charged on a regular basis.

You can see this sulfation reaction corrosion a lot in batteries near out of “useful life” or vehicles that rarely move.

Symptoms Of Car When Blue Battery Corrosion Occurs

When the battery terminal is blue battery corrosion will negatively impact the vehicle’s performance.

This is because resistive currents are created in the vehicle’s electrical circuits when corrosion occurs. These resistors have somewhat hindered the flow of electricity through the car’s electrical system.

All automotive electrical systems are assembled to run at a specific voltage.

Therefore, when the resistance created by the corrosion process at the battery terminals is too large, it can interfere with the flow of electricity.

This caused the voltage level to drop below the operating threshold of some devices inside the vehicle.

A car’s battery supports the starting process, like a single energy source.

For that reason, when the battery terminals are corroded, it will affect several systems installed inside the vehicle, especially those closely related to the start and charge process.

How To Remove Blue Battery Corrosion For The Car

Step 1: Proceed To Remove The Electrode Terminals On The Battery

Step 1

The first step in cleaning the battery terminal is disconnecting the positive and negative terminals according to the technique of moving the negative pole first and then the positive.

You will need tools such as goggles, specialized wrenches, and glove.

One thing to note is that you always need to wear gloves and goggles during the cleaning process to avoid being burned by leaking acid, thereby ensuring your safety.

Step 2: Clean The Car Battery Part.

Step 2

Do clean the battery part by following the steps below:

  • Apply detergent to both ends of the electrode.
  • Next, you scrub the electrodes with a brush to remove rust and blue stuff on the surface. After cleaning the electrode part, clean the end of the power cord.
  • You use clean water to remove the blue stuff around car battery that just melted for the next step. Be careful to use only a moderate amount of water and avoid spilling them on the bottle.
  • Once rinsed with clean water, dry the battery.
  • Finally, you need to apply a gel-based lubricant to the electrodes.
    This gel oil layer will help the head have better electrical contact and also help limit the corrosion and rust of the terminals after cleaning.

Step 3: Proceed To Use Specialized Battery Cleaning And Protection Agents.

Step 3

You will need the necessary tools, such as battery cleaning spray, anti-corrosion lubricant or protectant spray, water, and a brush.

Do this by following the steps below:

  • First, clean the car battery terminal by spraying cleaning solution on the wire and connector terminals.
  • It would be best if you waited a few minutes for the paint of the solution to dry. After that, continue to spray again and notice if the color of the spray solution in this spray changes or not.
    If the color does not change, the acid at the electrodes has been completely removed.
  • Rinse with clean water to remove the cleaning solution that has just been sprayed on the battery, and use lubricant to apply a thin layer to prevent corrosion.
  • The final step is to use a clean scrub brush to clean the car battery at the terminals and clamps.
    Repeat this process until the battery is completely clean, then spray a layer of protective lubricant on the terminals to complete.

Step 4: Reconnect The Wires To The Battery Terminals

Step 4

Connect the wire to the left battery terminal when it is removed. This means that you should start connecting from the positive terminal first.

At the same time, for batteries with the upper pole, shake the end of the cable to tighten it and then press it down.

Next, you need to tighten the battery terminal cover, and you’re done.


1, How To Prevent Blue Corrosion On Blue Stuff Around Battery Terminal?

Corrosion is a natural principle on many different battery devices, and there is no way we can prevent them from appearing.

But you can avoid a dense build-up of car battery blue stuff by cleaning the terminals and clamps.

Besides, instead of regularly leaving your car outdoors, park it in a covered garage or inside your house to protect the battery from rust.

2, Does Baking Soda Clean The Blue Stuff On Battery?

Yes, blue residue on car batteries has acid as its main ingredient. Therefore, an effective cleaning method for corrosive acids is to neutralize them.

You can mix baking soda with water to remove the blue residue from the car battery. After removing the residue, use a wet cloth to wipe it off.

3, How Often Should Car Batteries Be Cleaned?

Motorists need to clean the battery terminals of their cars once a year.

But, if you live in a foggy area, on salt roads, or your car is exposed to many corrosive substances, you should clean it more often, about every three months.

4, Do I Have To Replace The Car Battery When The Battery Has Blue Stuff?

No, blue-stuff corrosion is a normal physical phenomenon when the vehicle is exposed to corrosive substances. You need to clean it regularly to prolong the battery life.

If you experience any battery performance issues, then you should consider replacing the battery with a new one.


When you detect blue residue on car battery, it most likely indicates that the battery on your car is corroding. However, do not panic when you see this phenomenon.

Through this article, we hope you will learn basic blue battery corrosion cleaning skills and be motivated to have your car checked once a year to increase the life of your car.

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