A Complete Guide for Corroded Car Battery

Published on: June 7, 2022
Written by Liam Jaxon / Fact-checked by David Rowan

If you’ve seen a friable white or blueish substance on your car battery, you may have a problem starting your vehicle or experiencing other troubles. This is the cause of the corroded car battery. But don’t panic because this post will give you a complete guide for corroded car batteries and how to clean car battery corrosion from your car. 

Occasionally, battery connections might deteriorate, especially in cars that aren’t driven very often. Cars can have problems starting and charging their batteries when this occurs, so you may notice a decrease in battery life while driving. So why do batteries corrode?

complete guide for corroded car battery

Sometimes a bad alternator causes battery corrosion rapidly. In order to avoid generating corrosive hydrogen gas from overcharging the battery, corrosion must be prevented. Keep reading to learn more about the causes and remedies.

Car Battery Corrosion: What Is It?

A simple visual inspection will reveal corroded battery terminals. If you don’t know what battery corrosion is, you might see some white, green, or bluish substance on your car’s battery terminals or battery cables called corrosion. Anhydrous copper sulfate (ACS) or lead sulfate (LS) are the two most common white compounds found around battery terminals. In the presence of water, the color of anhydrous copper sulfate changes to blue.

Copper connectors are frequently damaged by hydrated copper sulfate, a blue-green material that develops around corroded battery terminals. An increase in the amount of resistance in a circuit caused by battery degradation makes it less efficient at conducting electricity.

As a result, transitory current flow, which often results in your car not starting, might be caused by increased resistance. Point to be noted that battery corrosion can sometimes be dangerous if mishandled.

Symptoms of Corrosion in Car Battery

The inability to start a car is the most common sign of a corroded car battery. So what happens if a car battery has corrosion? If a few signs occur, it might be the corroded battery problem. Even if you’re ready to put up with frequent reboots, linked issues can cause latent issues to surface. Insufficient power may cause problems with the radio or cabin lights.

If the issue persists, the car’s onboard computer may malfunction. The onboard computer collects data from many sensors to keep your car running, warn you of potential problems, and keep you safe. Ignoring concerns may jeopardize your and your vehicle’s safety.

Benefits of Using a Complete Guide for Corroded Car Batteries

1. Saving time and money: A complete guide for corroded car batteries can save time and money by providing information on how to properly care for and maintain your car battery, as well as providing troubleshooting tips and advice on how to fix common battery problems.

2. Increase battery life: A complete guide for corroded car batteries can help extend the life of your battery and ensure that it works reliably and efficiently.

3. Better performance: A complete guide for corroded car batteries can help improve the performance of your car battery and give you better fuel economy.

4. Safety: A complete guide for corroded car batteries can help keep you safe by providing information on how to properly install and use a car battery and how to safely dispose of a battery when it is no longer usable.

What Steps Should Be Taken to Ensure the Safety of a Corroded Car Battery?

1. Wear safety goggles and gloves to protect from splashing or spilled acid.

2. Inspect the battery for signs of corrosion, such as white powdery residue or greenish-blue stains.

3. If the battery is badly corroded, it should be replaced.

4. If the corrosion is minor, it can be cleaned with baking soda and water.

5. Use a battery terminal brush to clean the terminals and posts.

6. After cleaning, apply a thin layer of petroleum jelly or terminal protector to the terminals and posts.

7. Check the electrolyte levels and add distilled water to bring the levels up to the full mark, if necessary.

8. Recharge the battery if necessary.

9. If the battery is more than three years old, it should be replaced.

What Causes Corrosion in a Car Battery?

Battery corrosion is formed of sulfuric acid-derived hydrogen gas, and it reacts with other gasses in the air to generate the flaky green, blue, or white compounds seen on the battery terminal. It’s crucial to know what causes battery corrosion, whether it occurs quickly or slowly so that you can take steps to prevent it. Corrosion of a car battery can be caused by:

Poor Connectors

The type of battery connector you use can impact whether or not corrosion occurs. The sulfuric acid in the battery reacts with some battery connectors, causing this issue.

For example, aluminum and copper connectors typically react when exposed to sulfuric acid, resulting in corrosion of the car battery’s internal components. Even a loose battery terminal causes a car to stall. So check the terminals to identify the corrosion.

Combustion of Hydrogen Gas

Car battery corrosion is mainly caused by sulfuric acid leaking and releasing hydrogen gas. A mixture of airborne gasses, including hydrogen gas, is combined and crystallized. It’s a common indicator of battery over or undercharging.

Charging The Battery

Overcharging a battery can cause positive terminal corrosion. Overcharging a car battery usually occurs while connecting it to a battery charger for a long time and raises the temperature, and expands the electrolyte. The expansion pressure allows the electrolyte to run out of the terminals and induce corrosion.

Bad Alternator

Alternators keep your battery charged while in operation. But a defective alternator won’t work correctly and won’t charge the battery properly. As a result, the battery is undercharged.

So, a bad alternator ruins a battery first. Then the insufficient recharge accumulates white crystals on the battery, indicating deterioration and the need for a full recharge. So as a consequence, that bad alternator causes battery corrosion.

Old Battery

Even if you take great care of your vehicle, aged batteries might degrade. Batteries typically last five years, so if yours has, corrosion is likely. Some batteries may not survive close to five years before corrosion in their terminals affects their performance. Many things cause your battery to age rapidly.

Leakage of Electrolyte

Unsealed automotive batteries that need water topped up might suffer corrosion from electrolyte leaks. In this case, choosing battery water is an important factor. So you should know which water to put in the inverter battery?  Also, damage to the battery or poor maintenance might cause electrolyte leakage, causing corrosion. Corrosion happens when electrolytes spill on battery terminals during recharge. 

How Do You Fix or Clean a Corroded Car Battery?

Battery maintenance should aim to prevent corrosion, but it’s wise to learn how to fix a corroded car battery too. Nevertheless, here is an eight-step procedure for cleaning corroded battery terminals: When working with lead-acid batteries, always wear eye protection and use mechanic’s gloves.

1. Removing Battery Cables

Remove the battery cables first. Always begin with the negative battery wire, which is denoted with a negative sign (-), its acronym (NEG), and is black. The next step is removing the (+) or POS (or both)-designated positive battery cable.

2. Examine Battery Cables

Examine the battery cables for wear and corrosion. Also, look for broken, dried-out insulation. The copper stranding restricts current flow and brittles in the elements. Broken battery cables are a common cause of car trouble. If the battery cable is damaged, it’s ideal for replacing it.

3. Clean Up Battery Corrosion

If the battery or battery cables are corroded, apply a battery cleaning chemical to the corrosion. An industrial-grade battery cleanser eliminates corrosion while neutralizing acid. In this case, [amazon link=”B000CIRTY0″ title=”CRC 05023 Battery Cleaner” /] is the most popular one.

Several home cures also exist, but most do not clean, eliminate, or neutralize hazardous battery acid and cause more engine harm. Never use coca-cola to clean corroded batteries! 

4. Wipe and Clean the Battery Connectors and Terminals

Dry the battery, battery posts, and the battery terminals on the battery wire after removing the corrosion. A cleaning cloth made of microfibre is an excellent choice, such as [amazon link=” B0050R67U0″ title=” MagicFiber Microfiber Cleaning Clothes” /] absorbs and removes dust, oil, corrosion, and dirt very well.

Remove any leftover residue using a battery terminal brush. The [amazon link=”B0060YHP62″ title=”Schumacher BAF-B1 Battery Terminal Cleaning Brush” /] is a great battery terminal cleaning brush.

5. Protection of the Battery Terminal

Use anti-corrosion pads or terminal protectors on each battery post, preferably soaked in a battery corrosion prevention material.

6. Battery Cables Reattached

Reverse the sequence in which you connected the battery cables in Step 1. The positive battery cable should be connected first, and the negative battery cable should be connected last.

7. Battery Corrosion Prevention

Clean and lubricate the battery posts and cable connections with a thick anti-corrosion spray or brush-on coat. To prevent acid salt corrosion, [amazon link=”B000BOKML2″ title=”Permatex 80370 Battery Protector and Sealer” /] coat the terminals of the batteries it protects.

Prevention of Battery Terminal Corrosion

Regular automobile battery repair is essential to keep your car functioning smoothly. To avoid car battery terminal corrosion, use the following steps.

Always Check the Battery

The necessity of regularly inspecting your battery for corrosion cannot be overstated, whether it’s marine, automotive, solar or industrial batteries. This regular check will help you notice any development of corrosion on the battery. Beyond cleaning the corrosion, regular inspections will help you identify the source and fix it, keeping your car operating smoothly.

Dielectric Lubricant

Using dielectric oil on the battery connection also helps prevent corrosion. Disconnect the battery’s cables and apply the oil to both terminals. 

Petroleum Jelly

Corrosion can be prevented by putting petroleum jelly over the car’s battery terminals. Apply one tablespoon of petroleum jelly to the battery terminals while wearing latex gloves. Reinstall the battery, red cable first, black cable second.

Anti-Corrosive Washers

Anti-corrosion washers prevent corrosion on your car’s battery terminal. These washers are chemical pads that work to prevent corrosion. To use it, just separate the battery cables, insert the washers, and reconnect them starting with the positive and negative.

Protective Battery Terminals

These are little adhesive pads that go between the battery and the connector. The battery terminal shields are constructed of felt, which resists corrosion. Unplug the battery, place the protectors on top of the terminals, and then plug it back in.

Compression Copper Terminals

These tinned copper compression terminals are designed to fit the clamp snugly. In regions where the current flow from the battery to connections and other car parts is restricted, corrosion decreases.


1. Can a Corroded Car Battery Still Work?

There will be a decrease in current flow if enough corrosion has grown up on the terminals. As a result, you may need to jump-start your car to begin moving again. So it’s dangerous to run your car on a corroded car battery.

2. Should You Replace a Corroded Car Battery?

Changing the battery depends on the corrosive situation.

If the clamps on one or both terminals are corrosive or loose, then it’s time to change the battery. 

3. Is a Corroded Car Battery Dangerous?

It’s dangerous if hydrogen gas has corroded the connectors and batteries. It is normal to see sparks when you jump in your car. These sparks may ignite hydrogen in a faulty battery. Such an event could cause severe battery acid and lead injuries.

4. Can You Clean the Battery While Connected?

Yes, while connected, you can clean the car battery terminals. But for safety, you must turn off the ignition to clean the terminal and squirt it with hot water.

5. Can Vinegar Be Used to Clean Battery Terminals?

Yes, vinegar cleans car battery terminals very well. Vinegar is a potent acid that helps eliminate stubborn corrosion that impairs battery performance and car function.


There is no need to be afraid of corrosion on your car’s battery, but do keep an eye out for it. After reading this article on a corroded car battery, I hope that you now know how to identify and prevent battery corrosion in your vehicle. Cleaning your car battery of corrosion is the best activity to take to avoid unpleasant consequences. 

Featured image credit: commons.wikimedia.org

Related Posts:

Rate this post

About This Writer

liam jaxon author pic

Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

Leave a Comment