Causes of Corrosion Battery Terminal: How to fix it?

corrosion battery terminal

Causes of Corrosion Battery Terminal – Corrosion is a natural tendency of metals, and the metal in your car battery connections is no exception.

In reality, corroded battery connections are one of the most prevalent reasons for electrical complications and vehicle performance problems.

Corrosion is, however, inevitable, and you shouldn’t settle for subpar battery performance because of it.

Learn about why batteries corrode, how to recognize them, and what to do about corroded battery connections.

The corrosion battery terminal is a common problem. So, what’s going on here? How do we avoid it?

We’ll look at what you should know about battery degradation, how to prevent it, and how to clean it up when it happens.

Causes of Battery Terminal Corrosion

Batteries transform sulphuric acid into bursts of electricity that flow out through the corrosion battery terminal, and supplying power to your vehicle.

The alternator takes over the job of driving your car and powering its electrical functions once the engine is started.

Corrosion of a battery can cause its terminals to lose efficiency, resulting in a loss of battery power when it occurs.

causes of battery terminal corrosion

Electrolyte or electrolyte vapors that escape from the top of the battery are the most typical cause of battery corrosion.

The acidic electrolyte may condense on the top of the battery if hydrogen gas, which is produced naturally by the battery, is allowed to escape.

Because the battery terminal posts are made of two different metals, the second kind of corrosion occurs between them. Sulfation, the third kind of corrosion that occurs in batteries, happens internally over time.

If you have an aged, over, or under-charged battery, or if you’ve been exposed to corrosive elements (like salt or moisture), your car’s battery may corrode more quickly.

Corrosion can’t be avoided entirely, but it may be postponed with careful battery management.

Hydrogen gas and electrolyte vapor are produced by battery acid, which eats away at the battery. A number of circumstances might lead to corrosion on your battery connections.

The most prevalent causes of corrosion battery terminal are listed below in further detail.

Read also: Best Tips For Maintenance Of Your Car


If your alternator is mildly overcharging your car battery, corrosion on your vehicle battery terminals may develop.

To ensure that your battery isn’t charging higher than 14.5 volts while you’re driving, use a multimeter to test the voltage while your car is running.

With a car battery charger, you may be overcharging your vehicle battery.

Hydrogen gas leakage

The battery generates an electric current by turning acid into it. Hydrogen gas escapes from the battery at certain times and gets into the atmosphere.

Corrosion battery terminal occurs when it reacts with other chemicals. You can diagnose a variety of battery ailments depending on which side it appears on.

Undercharging is indicated by having it on the negative battery terminal, whereas overcharging is indicated by having it on the positive terminal.

A chemical reaction in the copper clamps

Copper is a durable material that does not corrode easily. But, copper sulfate is produced when electric currents flow via the copper terminals, which causes corrosion battery terminal.

Copper sulfate may be detected by a blue precipitate on the copper terminals. The reason you’ll have trouble starting your car is that copper sulfate does not conduct electricity well.

Electrolyte leakage

Lead-acid batteries are the perfect analogy for this issue. The electrolyte from the battery can leak and build up on the battery terminals as a result of aging or damage.

If you overfill the battery water, the likelihood of electrolyte leakage rises.

Overfilling the battery

As previously stated, overfilling your car battery may cause electrolytes to leak out. You should always double-check if you have a car battery that is refillable since not all of them are.

Read also: How to Fix Electric Parking Brake Problem?

How to Prevent Battery Corrosion

Ensuring that the alternator is not overcharging the car battery is the best way to avoid corrosion battery terminal.

You’ll also need a good battery in your vehicle. Corrosion protection can also be achieved with anti-corrosive sprays.

Let’s take a closer look at the various ways to avoid battery corrosion:

1. Replace the car battery

You may need to replace your car battery if a failing battery causes a lot of battery corrosion since this can occur again soon.

Anyhow, replacing car batteries every five years is a good idea to keep them in good shape.

2. Copper compression terminals

These clamps help to avoid future corrosion battery terminal and are among the best on the market. The clamps are tinned copper and ensure that the complete clamp is in touch with the electric current.

3. Battery charging

Corrosion battery terminal can be caused by an overcharging or undercharging battery.

The manufacturer’s manual usually includes the suggested battery voltage. Make sure you aren’t charging your car battery too much using a car battery charger.

It’s also a good idea to measure the voltage when the car is idling. There is something wrong with the alternator if it is charging above 14.5 volts.

4. Anti-corrosive sprays

To avoid terminal corrosion, there are several sprays available on the market. If the sprays are too expensive, you may use Vaseline or grease instead.

To avoid corrosion of the battery terminals, coated felt pads might be utilized.

Read also: Extend the Life of Your Car Battery With These 5 Tips

How to Clean Battery Terminals

corrosion battery terminal cleaning

Now, we must understand how to corroded battery terminal fix once we know what causes it. To clean the battery terminals, there are a variety of methods you can use.

Baking soda – water solution

To eliminate copper sulfate from the terminals, you’ll need a brush and baking soda water solution.

First, make sure the vehicle’s ignition is off. By unscrewing the battery terminals, you can clean some of the corrosion off your brush.

When pouring the baking soda solution, keep brushing away the corrosion. Next, clean the terminals with some clean water.

Smear some wheel bearing grease on the terminals to prevent additional damage. For some individuals, petroleum jelly is an acceptable substitute for greasy, however, it does not last as long.


The majority of the carbonated beverages we consume contain carbonic acid. Sprinkle some soda on the terminals, then use a soft brush to clean off the buildup. In the absence of a baking soda and water combination, this works well.

Corroded battery terminal cleaning

If your battery has too much corrosion on the terminals, you’ll have to use a baking soda-water solution and an old toothbrush.

First, remove the negative battery terminal corrosion. Mix the baking soda in small cups. After soaking each terminal in the solution for 20 minutes, remove it and allow it to dry.

Remove the corrosive materials from the connections with a wire brush. Make a new soda solution by pouring in the existing one.

After you’ve washed off the corrosive substances, re-soak the battery terminals. Clean the terminals with a wet towel or allow them to dry.

To clean the terminals, you may also use sandpaper. Reattach the terminals in a positive sequence, applying grease or Vaseline.

Frequently Asked Questions (FAQ)

Is corrosion on battery terminals normal?

Corrosion is a characteristic of metals, and your car battery terminals are no exception. Corroded battery terminals are one of the most prevalent reasons for electrical issues and degraded vehicle performance.

What happens if battery terminals are corroded?

Corroded car battery connections may cause a variety of issues. They may also damage the alternator and prevent your battery from completing charging (resulting in your automobile not starting).

Does corrosion mean I need a new battery?

Corrosion around your connections in other vehicles with standard flooded lead-acid batteries doesn’t necessitate that your battery is replaced; instead, it suggests that there may be significant resistance developing in those locations, making it more difficult for your battery to provide and accept the power to the vehicle.

Will corrosion keep a car from starting?

Under the hood of your car, battery corrosion is a frequent but serious problem. Your battery’s power may not be delivered to the rest of your car if there is too much corrosion build-up, which may make it difficult to start.

What is the best thing to put on battery terminals to prevent corrosion?

Once you’ve removed the terminals, apply anti-corrosion washers or a little amount of dielectric grease to your battery’s posts. Another excellent anti-corrosion chemical is the AMSOIL heavy-duty metal protector, which may also be used to avoid corrosion.

The Final Verdict

Keeping your vehicle running smoothly and avoiding expensive repairs involves cleaning the corrosion battery terminal.

Depending on the degree of corrosion present, there are a number of alternative ways you may employ. When working with electricity, however, always use caution.

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