What Causes Car Battery Corrosion and How To Remove It

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Car battery corrosion is something that you will likely experience in your car at some point or another. 

But it can be difficult to decide when corrosion is abnormal and causing damage to your battery. 

Don’t worry. In this post, I will review everything you need to know about car battery corrosion, including causes, symptoms, and how to remove it.  

Let’s get started. 

What Is a Car Battery Corrosion?

Car battery corrosion occurs when battery fluid and gases escape from the battery and damage the battery’s outside. 

This is a common problem, and it can become serious if not addressed early. 

Battery corrosion can decrease the life and performance of car batteries. It can also cause a complete loss of power, difficulty starting, slow cranking, or rapid clicking when trying to turn the car on.  

Battery corrosion can take on various forms. Below are the different types of battery corrosion that typically takes place on car batteries

  • Terminal clamps and electrodes turn green or white. 
  • White sulfur crystals grow on the battery terminals.
  • Battery fluid spilling or staining electrodes or battery surface

If you see any abnormal build-up or stains on your battery, you should inspect your battery further. 

Can a Corroded Battery Still Work?

Yes. Corroded batteries will still work for some time. In most cases, the battery will work fine for some time.

As the corrosion progresses, the battery will slowly stop working. The most common side effect and often the first issues that corroded car batteries cause are that your car won’t start or you’ll lose power to the electronics in your car.

Battery corrosion won’t destroy your battery from working immediately. Over time the corrosion will become less effective, and eventually, it will stop working.

You must take immediate action if you recognize corrosion on your car battery.

Does a Corroded Battery Need to be Replaced?

You don’t always need to replace a corroded battery. Some corrosion will occur naturally due to the heating and cooling of the battery during everyday use.

It’s important that you clean and maintains your battery when you see corrosion on your battery.

The severity of the damage will determine if you need to replace your battery.

Surface level corrosion can be easily cleaned.

If the corrosion has caused serious damage to the clams, wires, metal rods, or battery casing, then you should consider replacing the battery.

If you are uncertain of the damage, you can have a mechanic inspect the battery. Mechanics can typically determine the severity of the damage quickly. They can help you determine what steps need to be taken. 

What Causes Car Battery Corrosion?

Unfortunately, there is not one condition that causes your battery to become corroded. Many different things can cause battery corrosion. 

Below are some of the reasons that your battery is getting corroded. 

1. Normal Gas Release

One of the most common reasons for corrosion is just the normal use of a car battery. When in use the car battery loses power. Then your carburetor recharges is when it’s not in use.

When this happens the lactic acid in your battery is heating up and cooling down. This produces hydrogen gas that is vented outside the battery.

When the hydrogen gas exits the battery it’s released into your engine bay. These tight spaces make it hard for the hydrogen gas to escape.

This hydrogen gas can get trapped near your battery and cause corrosion around the terminals and electrodes.

2. Car Battery Undercharged

Think of it as your mobile battery. The more you use it while charging, the more it will never get full until you stop playing with it.

The car battery’s undercharging happens if there’s not enough time to refill and recover the lost energy. It can be because of the high electrical demand used while driving, but there’s only less time recharging.

Our car batteries also need some rest or cool down, especially for long drives. It is the reason why we do ‘stopovers’ in between a long journey.

3. Car Battery Overcharged

As people would say, ‘too much of everything is bad.’ Continuous charging also hurts your car’s battery.

Overcharging can decrease its general lifespan and may cause excessive gassing. It will eventually lead to a faster corrosion process.

It may be gradual, but it would cause several problems if you don’t pay attention to the battery.

4. Refilling Battery Incorrectly

Some batteries require water refills to operate at maximum efficiency. It’s important that you first make sure your battery is refillable.

Not all batteries are refillable. When you do refill your battery, it’s important that you don’t add too much liquid.

You can visit your car battery brand’s website for more information on how much water should be inside the battery.

If you do overfill the battery, the spilling water can eventually result in battery corrosion.

5. Battery Electrolyte Leaking

Leaking is standard in older batteries or damaged batteries. If leaks are severe, corrosion can progress quickly and wreck the battery.

The electrolytes will damage the electrodes and terminals. This leakage will become corrosion.

6. Battery Age

Car batteries have a lifespan of five years on average. When your battery begins to reach its lifespan more likely to become corroded. 

This is because all the main issues that we listed above are more likely to occur to older batteries. Older batteries begin to wear down which means that they are more prone to leaks, or malfunctions. 

If your battery is old it’s highly recommended that you replace your battery because corrosion will destroy an old battery much faster than a newer one. 

Symptoms of A Corroded Battery

You won’t notice that you have a corroded car battery most of the time until you check it. Some moments, you would also see some signs and symptoms wherein the battery is near its end.

The car battery can only do its job when it has an intact connection. Factors like corroded cables and terminal or loose-fitting terminals can lead to malfunction.

As a result, it will limit the alternator’s ability to charge the battery. Your car won’t also have sufficient power to cover its electrical accessories such as the radio and headlights.

Here are some symptoms to check if you can see the white, green, or bluish corrosion.

1. Problems Starting the Vehicle

One of the main functions of the battery is to turn on your car. Most cars today rely on an electric starter. Without a properly functioning battery, your car won’t start.

Even a small amount of corrosion can cause significant decreases in battery voltage. You typically need at least 12v to start your car. A corroded battery can fall below 12v relatively quickly.

2. Dim Lights and Loss of Electrical Power

Have you noticed that your headlights or interior lights are too dim at night? It may be because there’s severe corrosion in your battery’s terminals. 

Any damaged or corroded terminal is not suitable for any electrical contact. One of its effects is the total loss of power of all electronics in your vehicle.

It includes the lights, radio, to your dashboard computer. In this case, you need to replace your car’s battery.

3. Poor Fuel Efficiency

You might be surprised, but a weak battery can actually cause poor fuel efficiency.

The main reason for this is because your engine won’t get the proper fuel-air combination. With corrosion, your battery will have reduced power.

This can cause your spark plugs to malfunction and reduce your fuel efficiency. Your engine will be running on a fuel-air combination that is less than ideal.

4. Car Computer Efficiency

Corroded batteries force your car to operate with a battery that has less than a full charge. Car computers tend to operate at less than optimal levels when the battery is dying. 

This lack of power can cause issues with your car’s computer. One of the most common signs that your battery is affecting your computer is poor performing sensors. This includes: 

  • fuel gauge sensors
  • camera sensors
  • lane change sensors
  • Mass Air Flow (MAF) Sensor.
  • Manifold Absolute Pressure (MAP) Sensor
  • Engine Speed Sensor
  • Coolant Temperature (CTS) Sensor

Often times sensors will completely stop reading, get stuck in a single position, or give inaccurate readings. 

How to Remove Car Battery Corrosion?

You don’t always need to replace your battery when there is corrosion on it.

Unless your corrosion has completely damaged your battery, in most cases, you can clean the corrosion and your battery will return to its normal state.

There are different cleaning methods you can use to remove corrosion. The option you choose will depend on your budget and what you have available.

Before you begin any cleaning method it’s important that you always wear the proper protective equipment. This includes:

  • Goggles
  • Rubber gloves with long sleeves
  • Face mask
  • Battery terminal wrench

1. Mild Corrosion: Water and Baking Soda

One of the cheapest and easiest ways to remove corrosion is using baking soda and water. This is a great option because most people have baking soda in their homes.

If you don’t, then you can borrow some from your neighbor. This method is only effective on mild to light corrosion. If the corrosion on your battery is heavy, it’s possible that baking soda won’t be strong enough.

You can use the following recipes when cleaning your battery.

  • One tablespoon of baking soda for every two cups of warm water

To make applying the baking soda easier and more effective, you can remove your car battery. This step should be done carefully. 
For easier access, you can remove the battery from your car. But only do this if you know how to.

Once you think that there’s enough solution on the corroded area, scrape it off with a wire brush. If you don’t have one, any spare toothbrush will work just fine.

Apply baking soda solution to any areas that experience corrosion. One applied to use a wire brush to remove any corrosion. You can also apply the baking soda solution as you brush the battery.

If you can’t notice any corrosion anymore, carefully rinse it with water. Finally, wipe the battery with a clean cloth.

2. Using Coke Or Other Soda

Soda also has elements that can clean mild corroded parts of a car’s battery. It is a great and accessible alternative to baking soda.

Most sodas have the acidity that is from Phosphoric acid. It is a type of acid that is effective in removing rust.

The process is simple and the same with baking soda. The difference is that you don’t have to mix anything.

You only need to buy any soft drink that contains carbonic acid. You can either read the ingredients used or search online.

But don’t worry because most sodas have carbonic acid. Then, pour over some soda over the corroded area.

Continue brushing it until you finally remove the corrosion. Finally, use a sponge to remove any residue.

3. Use Commercial-Grade Battery Cleaner

Soda also has the elements that can clean mild corroded parts of a car’s battery. It is a great and accessible alternative for baking soda.

Most sodas have the acidity that is from Phosphoric acid. It is a type of acid that is effective in removing rust.

The process is simple and the same with baking soda. The difference is that you don’t have to mix anything.

You only need to buy any soft drink that contains carbonic acid. You can either read the ingredients used or search online.

But don’t worry because most sodas have carbonic acid. Then, pour over some soda over the corroded area.

Continue brushing it until you finally remove the corrosion. Finally, use a sponge to remove any residue.

How to Protect your Car Battery from Corrosion?

Prevention is better than cure, and it is also applicable to car batteries. It only lasts for a certain period, but protecting your car battery ensures a safe and convenient drive.

If you want to keep your car battery’s condition, cleaning and maintenance are essential.

You can try using anti-corrosive sprays and even grease or petroleum jelly. These have special formulas that prevent corrosion.

As mentioned earlier, avoid overcharging and undercharging the vehicle’s battery. Always stick to the manufacturer’s manual for the recommended voltage for the battery.

Finally, create a calendar or schedule of your car maintenance and stick to it. Car maintenance is as important as following road signs and obeying the registration process.

Frequently Asked Questions (FAQ)

Is battery corrosion dangerous?

Battery corrosion is not dangerous, but the implications that can happen can pose threats for the driver. For example, a damaged battery can cause sparks during ignition.

Hence, it could cause an explosion that would send battery acid and lead flying. As a result, it will leave devastating damage and injuries to you.

Can I Drive with a Corroded Battery?

If you don’t want to risk getting stuck in the middle of a highway, you can’t drive with a bad battery. First of all, it is not safe.

You’ll never know when a bad battery will bring you down. It can be under scorching weather or during a long drive far from any car repair shop.

Driving with a bad battery is like picking your poison. It will give you a high possibility of accidents and sudden stops.

Worst of all, a battery with acid leaks may explode. It will lead to life-threatening injuries.

Is corrosion a sign of a bad battery?

Corrosion is one of the many signs of a bad battery, but there are other common signs like poor maintenance and aging. If you’re often driving, it can be normal wear and tear.

What if you can’t see any corrosion, but the battery is still underperforming, and it has been frustrating more often? In this case, try looking for splits and leaking acid.

Why does corrosion come in different colors?

Corrosion may appear in white, green, or bluish colors. It differs depending on the type of metal used on the battery and several environmental factors.

As the acid vapors escape the battery, it interacts with the copper material on the battery. As a result, you can see bluish corrosion.

White corrosion, on the other hand, is because of lead sulfate. It happens because of the improper flow of electrons through the battery.

Regardless, the color of the corrosion doesn’t indicate the intensity of the corrosion. It only varies depending on elements and chemicals reacting to one another.

Is car battery corrosion dangerous to touch?

Lead-acid from the batteries are only dangerous to the sensitive parts of the body. When you’re trying to fix it, always remember to wash your hands. It’s because chemical burns can hurt a lot, especially on your eyes

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