Disconnect Your Battery Cables
To avoid being struck with electricity and being severely burnt, make sure to disconnect the negative battery cable BEFORE the positive battery cable.
You can identify negative and positive cables by checking what theyre marked by: the negative sign , the abbreviation NEG, and/or the colour black and the positive sign , the abbreviation POS, and the colour red.
Removing Battery Acid Residue
Removing the acid residue is actually very easy. You need to neutralize the acid with a base . Thankfully, you have one in your home – baking soda.
Simply mix half a cup of water with a tablespoon of baking soda. Then using a paper cloth or an old wire brush, apply it over the posts and terminals. It should begin fizzing, which is an indication the reaction is working. Rub the posts and terminals well and wipe all the residue off. Its best to use a paper towel or a sacrificial rag – you dont want to keep this stuff around – neutralized or not.
Finally, wipe the battery with a wet cloth. If there is grease and grime accumulated on top, you can use a small amount of degreaser to remove it. Alternatively, dish detergent should also work.
Just remember that you dont want to pour water or liquid over the battery. Some of it can seep through the vents or seals and contaminate the electrolyte which will reduce the performance of the battery.
Alternatively, you can use one of the many available battery cleaning solutions. These are formulated exactly for this purpose and some of them have a color-changing effect that indicates the presence of any acid residue. These are fancy and work great, but are not absolutely required to get the job done.
Sometimes, the copper terminals have corroded too much. They can easily be replaced and cost $5 – $10 dollars for the pair at pretty much every auto care center.
How To Remove Car Battery Corrosion
It is advisable to take your vehicle to a mechanic for corrosion removal and further battery maintenance. However, if the corrosion isnt too bad and you have previous experience of fixing your cars battery, you may proceed with the DIY.
First of all, make sure you have all the required equipment.
- Cleaning solution battery cleaner, baking soda, etc.
- Wrench for detaching battery cables
- Battery brush for scrubbing
- Gloves or rags
STEP 1: Inspect the battery for signs of swelling or bloating. If you detect those issues, it may not be the best idea to continue with this DIY. You might need to replace the battery.
STEP 2: Turn off the car ignition and detach battery cables. Make sure you detach each cable sequentially to avoid hazards. Remove the black cable from the negative terminal. Detach the positive cable from the positive terminal having plus sign.
In case the terminal of your cars battery is badly corroded and stuck, apply the terminal cleaner instead of breaking the terminal.
Clean car battery corrosion. There are several solutions that will help loosen the build-up.
- Apply baking soda solution. A chemical reaction is triggered when the baking soda solution is applied.
- Place a paper towel or tissue paper soaked in baking soda solution on the battery terminal.
- Additionally, a corroded battery clamp can be soaked in the baking soda solution for a few minutes.
- Scrub after about 20 minutes
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What Is Car Battery Corrosion
The reason car rust and car battery corrosion are so different is the presence of a unique rust-causing agent that does not typically affect the rest of the car. That is the sulfuric acid vapor produced during the working of the battery. At the high temperatures of the engine bay, this vapor and all the factors described in the introduction combine to corrode the lead and copper joint of the battery terminal in a way far more different and harsh than the moisture and oxygen corroding the cars structural steel components.
As Sulfur Dioxide and Hydrogen are gases, they evaporate from the reaction site. Water , Lead Sulfate and Copper Sulfate stay on the terminals. Copper Sulfate is soluble in water, and it gives the rust a light blue color which is dominated by the white Lead Sulfate.
At a solubility of just 0.0032 g/100 mL, Lead Sulfate cannot dissolve in water to form a solution and forms a paste instead. This paste dries and hardens under the heat of the engine.
The corrosion on a car battery terminal does not conduct electricity. All of the problems it causes are by hindering the path of electricity resulting in elevated battery temperatures and decreased life and efficiency.
It looks daunting, but car battery corrosion is easy to clean.
Lubricate Or Protect The Terminals Before Reconnecting

Before the terminal clamps are reattached, use a small amount of petroleum jelly inside of the terminals before reconnecting them to the battery. This will help you reconnect them and prevent future corrosion. Use a different rag to apply, says Meineke.
Of course, there are specific products like CRC’s battery terminal protector thats said to last longer and prolong the battery life. Like the battery cleaner, it’s not that expensive, but petroleum jelly is the cheaper option and works fine.
Make sure you connect the positive terminal first before the negative terminal. Then put the junction covers back on and turn the car on. If the car is still experiencing problems, it may need to be looked over by a professional.
All in all, if you have battery corrosion build-up, as long as you have the needed items, it can take as few as fifteen to thirty minutes to fix and be back on the road again.
If you do need something from the list like the wire brush, which can be expensive in stores, check out products on Amazon which usually sells cheaper packs of brushes.
Have a question about the process? Leave a comment below. Remember, all you have to do is:
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Disconnect the battery
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How To Clean Car Battery Terminals
- Neutralize the car battery acid.
- Clean the terminals.
These two are typically done in a single step. There are two methods to do this:
Use a Car Battery Cleaner
The best and easiest way is to buy a battery cleaner from an auto parts store. These products are designed to neutralize the acid and clean the terminals at the same time. The instructions for the use of these vary from product to product, but here is the general procedure:
- Apply a generous amount of the cleaner to the terminals of the battery.
- Let the cleaner sit for a couple of minutes to neutralize the acid and soften the corrosion.
- Use a toothbrush to agitate and remove the corrosion entirely from the terminal.
- Rinse the terminals thoroughly with clean water.
- Dry the battery and surrounding area with compressed air or a used towel.
Use Baking Soda
Suppose you cannot get a commercial car battery cleaner. In that case, you can make do with a common household material, baking soda. As baking soda is alkaline in pH, it can neutralize car battery acid and soften the rust.
- Take a glass of drinking water and dissolve two tablespoons of baking soda in it.
- Soak your car battery terminals in the solution for a few minutes.
- Use a toothbrush to agitate and remove the corrosion from the terminals.
- Rinse the battery with clean water and then dry it with a used towel or compressed air
Preparation And Clean Up
Dry off the battery, wiping it down with a clean rag. Wipe down the battery cables. Discard your rag. Apply petroleum directly to each battery post liberally. Reconnect the battery cables beginning with the positive connection followed by the negative connection. Tighten each connection with your pliers or wrench. Remove all tools and supplies, close the hood and start your car to ensure that it will run. You might also consider moving the car away from the work area and bringing out the garden hose to wash away the corrosive residue left on the ground.
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Clean The Car Battery With Wd
When you dont have other car battery cleaning agents, WD-40 can also do the trick of cleaning your car terminal, but you need to work a little harder. So, this is how to clean car battery terminals with WD-40.
- Disconnect the terminals.
- Now, spray WD-40 on the battery terminals and connections.
- Rinse properly with hot water when you have left the WD-40 for some minutes.
- Then, scrub with your brush and ensure all the corrosion comes off.
- You may rinse it again till it is completely clean.
- Dry the terminals and connect them to their place.
Take Steps To Prevent Corrosion In The Future
Theres a simple step that can prevent your battery terminals from getting corroded and never require cleaning again. Apply dielectric grease on the terminals once they are in place. It is essential that you apply it after tightening the terminals. This grease is an insulator and can hinder the proper current flow if applied before the terminals are tightened down.
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Chemical Reaction On Copper Clamps
The copper in the terminal clamp is a good conductor of electricity and doesnt corrode easily.
However, the combination of leaking sulfuric gases from the battery and an electrical current can create copper sulfate, which causes corrosion.
This blue-green substance you see on a terminal isnt a good conductor and should be cleaned.
Use Corrosion Inhibiting Pads
Corrosion inhibiting battery post pads can be used singularly, or in conjunction with a chemical derived corrosion inhibitor to keep such build-up from occurring.
These pads are most generally saturated in a corrosion-resistant compound, and are intended to prevent hydrogen gas from escaping between a batterys casing and posts.
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Why Do Car Battery Terminals Corrode
A battery is just one big chemical reaction, and the white, scaly deposits on the posts are simply one of the byproducts.
A typical car battery is made up of individual cells, with each housing alternating plates of lead and lead coated with lead dioxide submerged in a sulfuric acid solution. This causes a chemical reaction that releases electrons, providing the juice that spins the starter motor, powers the radio and keeps the lights on, among other functions.
Sometimes, especially on cheap batteries, the seal around the post allows sulfate in the battery to escape and react with lead in the post, producing white, flaky deposits. If bad enough, theyll interfere with the battery connections and prevent the flow of electricity, leaving you stranded.
Check The Battery Cables For Damage

Damaged and worn battery cables are a common culprit for non-starting engines. If you notice that the cables insulation is showing signs of corrosion, or are frayed, splintered, peeled, dried, or cracked in any way, then that should serve as an indication that you should have them replaced straight away.
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Ten Tips To Remove Battery Corrosion
Corroded battery terminals often mean your car will not be running at its peak but there is an appropriate way to clean them to ensure it is as safe and environmentally friendly as possible.
Mixing water and baking soda is a common home remedy for removing corrosion from battery terminals but considering water and electricity do not mix it isnt the safest solution. A 12 volt shock may not seem too dangerous to you, it will cause damage to your car by discharging sensitive electronic devices.
Here is a method that will not cause damage to your car but we must warn you, the following tips involve working around and near acid and involve chemical reactions producing heat. Please take all care to ensure your safety. If you are not confident in your ability to handle dangerous substances, seek professional advice from a certified mechanic. Wear protective eyewear, gloves and suitable clothing. If acid comes in contact with your skin or eyes, flush with warm water for at least fifteen minutes and seek immediate medical advice.
Remove Car Battery Corrosion
Take your teaspoon and fill it with baking soda. Combine this powder with your cup of water and stir. Gradually pour approximately half the solution over each battery post, then place this mixture to the side. Take your wire brush or old toothbrush and brush off the remaining corrosion. You can dip the brush into the mixture or pour the remaining amount over the terminals as needed. For tough cases allow this solution to penetrate for at least five minutes. Continue brushing until all corrosion has been removed.
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Assemble Your Tools And Supplies
Gather the essential tools and supplies required to tackle this job. You will need to put on a pair of safety glasses and work gloves. Avoid wearing your good clothes as you will come in contact with grease and dirt. You will need a stiff wire brush, a cup of lukewarm or cold water, a box of baking soda, a teaspoon and rags. An old toothbrush, pliers, a wrench and petroleum jelly round out your tools and supplies.
Removing Car Battery Corrosion With Baking Soda
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How To Clean Car Battery Corrosion Quickly And Easily
As your vehicle gets older, its only natural to expect a bit of battery corrosion to build up over time. Nobody can avoid it, as it is just a symptom of flooded battery ownership. But if you want to know how to clean it easily, this guide will help you through that.
The simplest way to clean your car battery is through a mixture of water and baking soda. Mix the two in a half-and-half solution and remove the dirty surface with a stiff brush. After enough time, you will see that your battery is clean.
There are many more forms that you can use to clean your battery. Below, we will get into different ways you can do so and many corrosion types. Be sure that you wear safety glasses if you make any sort of battery-related checks to your car.
Disconnecting Your Car Battery Safely
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Guide To Cleaning Car Battery Terminals Safely
What Causes Car Battery Corrosion

Battery corrosion around the posts of the battery is caused by the sulfuric acid and hydrogen gas vapor that can escape from the battery. Sometimes this vapor is vented out of the top vent blocks on the battery, but other times, small amounts of this vapor leak out in the area between the posts and where they seal to the plastic battery casing. This vapor mixes with other gas under the hood, the heat of the engine, the differences in lead composition between the posts and the terminals, the copper of the battery wires, and creates corrosion. Under the hood of a car, temperatures can exceed 250 degrees, and this heat causes the metal of the posts and the plastic of the casing of the battery to expand at different rates. This is the reason why you rarely see corrosion on the posts of a battery thats under a seat, or in the trunk of a car. These batteries arent exposed to the extreme temperatures you find under the hood.
Cleaning corrosion off of your car battery terminals is not a complicated process. You dont have to take the car to a mechanic or rely on any advanced, complicated techniques to get yourbatterylooking like new. You can either use one of our battery cleaning solutions or a combination of baking soda and water. Its recommended that you use either a battery cleaner brush tool, or a very small wire brush to do the cleaning, along with a solution.
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