Car Battery Corrosion | A Complete Guide on How to Keep Your Car Battery From Corroding


car battery corrosion

Car owners often face a number of problems and one of such problems is car battery corrosion. While there are several causes of car battery corrosion, the fact remains that it is something nobody wants to encounter and if you are wondering what causes car battery corrosion and how to fix it when it occurs, then you have found the right resource.


Car battery corrosion is sometimes caused by overcharging the battery. When a car battery undergoes overcharging, its positive terminal begins to corrode. If the car battery corrosion is on both terminals, chances are that the battery is suffering a chemical reaction that occurs in your battery clamps during electric flow. Furthermore, car battery corrosion can occur when your car battery is exposed to certain elements.

Whatever the cause may be, car battery corrosion does nobody any good. It is one thing you must avoid and take serious when it occurs. In today’s article, I would be answering some of the questions people ask as regards what causes car battery corrosion, how to fix car battery corrosion, and many others.

What Does Car Battery Corrosion Look Like?

It is possible you have no idea what car battery corrosion looks like. Well, you are not alone. Not so many persons can see a corroded battery and tell it is undergoing corrosion. If you are in this category, you do not have to fret, the next paragraph explains what car battery corrosion look like.

Car battery corrosion looks like a powdery, crystal-like growth on the terminals of your car battery. When a car battery is suffering corrosion, it will look like there is a rocky growth or mold growing on the car battery. If you notice any of such, then your battery is facing corrosion and you must apprehend it swiftly.

What Does Corrosion on Car Battery Mean?

Corrosion on car battery can mean different things. Sometimes, your car battery may be facing corrosion only on the positive terminal. Other times, both the positive and negative terminals may be corroded.

When your car battery is undergoing corrosion only on the positive terminal, it means the battery is getting overcharged. That is, there is too much current flowing in the battery due to overcharging. I will explain what this means later on. While if the car battery is corroding on both terminals, it is likely because of an exposure to certain elements or a chemical reaction going on in the battery.

What Causes Car Battery Corrosion Only on the Positive Terminal?

I have explained in the paragraphs above that when you notice that the only sign of car battery corrosion in your car battery is on the positive terminal, it means your car battery is being overcharged. Overcharging a battery cell will typically create problems for the battery and this is not different for car battery.

When a car battery suffers corrosion only on the positive terminal, it is because the battery has become overcharged and the electrolytes have begun to move rapidly around the battery cell. Electrolytes are chemicals present in your car battery and when your battery overcharges, the volume of electrolytes in it increases thereby causing the battery to swell.

You will have observed a phenomenon like this when you charge your phone to the extent the battery starts swelling. If you continue charging, the phone battery will swell beyond limit and explode, destroying the phone. In the case of a car battery, once the volume of the electrolytes go beyond the breaking point, it looks for any available vent or hole to escape through and they always escape through the positive terminal.

Because the electrolyte reaction cannot escape the car, it forms the powdery buildup on the positive terminal and when it solidifies it becomes crystalline. And that what causes car battery corrosion only on the positive terminal.

What Causes Car Battery Corrosion on Both Terminals?

There are three reasons which are typically agents that cause car battery corrosion on both terminals. If you notice that both terminals on your car battery are suffering corrosion, it could be caused by:

  1. A chemical reaction between the copper clamps and the battery terminals
  2. Leaks around the battery terminals
  3. Exposure to elements

If the cause of your car battery corrosion on both terminals is due to the chemical reaction between the copper clamps and the car battery terminals, there is not much that can be done. For your car to make use of the battery, it must be clamped to the terminals, hence this chemical reaction must occur. The only way out of this dilemma is to try and keep the point where the clamps and terminals meet clean.

For leaks around the battery terminals, it will be wise to get your battery looked at as that would require the expertise of a professional to correct.

What Causes Car Battery Corrosion (Not on Terminals)?

Car battery corrosion not on terminals is possible. It means the battery is getting corroded but it is not showing up on the terminals. The possibility of car battery corrosion not on terminals depends on the kind of battery first and then in the event of a break or leak on the battery.

If you notice that your car battery corrosion is not on its terminals and the battery needs water to be added to it, then chances are that the battery cell was overfilled with water which caused an electrolyte leakage thereby leading to corrosion.

In the case of the battery being broken or cracked, you would need to get it checked. These are typically reasons that causes car battery corrosion not on terminals.

Does Corrosion Affect Car Battery?

If car battery corrosion was something one could manage I may not have dedicated a post like this to detail what causes car battery corrosion and how to prevent it. The truth is, car battery corrosion affects the car battery and it could get out of hand if not taken seriously.

Corrosion affects a car battery by making the battery weaker. When corrosion starts, it increases rapidly and makes both the terminals and the battery itself weak. With time, the corrosion will make the car battery to be burnt inside. When the battery gets burnt inside due to corrosion, it will be unable to maintain a charge or start your car like it used to.

In summary, yes, corrosion does affect a car battery.

Is Car Battery Corrosion Dangerous?

Yes, car battery corrosion is dangerous. When we talk about corrosion, we are talking about electrolyte, lead, battery acid, and other dangerous stuff trying to escape from the car battery. If you have no idea what these things are, I can help you for free, they are dangerous substances that you must not come in contact with.

Seeing that majority of the time when car battery corrosion occurs, there is the escape of harmful substances from the battery, it is only wise to come to the conclusion that car battery is both dangerous and unsafe for everyone.

It is important to note that, in adverse cases of car battery corrosion, there is the risk of explosion which has the potential of inflicting serious havoc and injuries. Whenever you notice signs of corrosion, take the necessary precautionary measures and inform a professional to examine your car battery.

Can You Drive With A Corroded Battery?

The question above has a twist. Yes, you can drive with a corroded battery and No, you should not drive with a corroded battery. A corroded battery may start your car after a couple of tries and can even power the car as you commute but you risk the chance of facing an explosion when the corrosion is caused by a leak or crack.

While you can drive with a corroded battery, my advice is that you should not. Once you observe that your car battery is corroded, get it checked and do not drive under such circumstances. You will be saving yourself a lot of harm as well as other road users.

Is Car Battery Corrosion Dangerous To Touch?

The truth is, when the car battery corrosion is caused by the chemical reaction between the car’s copper clamps and the battery terminals, it may not be harmful to touch. However, if the corrosion is caused by a leak or there is a crack through which the chemicals in the battery are escaping, it will not be prudent to touch it.

To be on the safe side, do not touch the corrosion on a car battery.

Can Battery Corrosion Keep a Car From Starting?

Yes. If the battery corrosion is on the positive terminal it can stop a car from starting. The positive terminal of a car battery is needed to be charged up for the car to start. When the positive terminal is corroded and the corrosion is prevent the terminal from getting charged, the car will not start.

Before you dismiss that only corrosion on the positive terminal can keep a car from starting, it is quintessential to note that if the negative terminal is corroded, the car may not start as well. Corrosion on a car battery blocks the electric charge and when it is not available, there is no way ignite the process that makes a car start.

How Do You Fix Corrosion On a Car Battery?

There are two popular methods to fix corrosion on a car battery which depends on what is causing the car battery corrosion. To fix corrosion on a car battery if it is caused by the chemical reaction between the copper clamps and the battery terminals, clean off the terminals after disconnecting it from the copper clamps.

If the corrosion is caused by a leak or crack in the car battery, to fix it, mix a solution of warm water and baking soda. Disconnect the battery cables, take a toothbrush dipped in the solution and scrub the corrosion away. It will clean up and then you will have your battery restored to normal.

Be sure to check with a professional to be sure the problem can be curtailed. Otherwise, get yourself a new car battery.

Car Battery Corrosion Prevention

car battery corrosion prevention

These are the steps to take to prevent car battery corrosion:

  1. Keep the connection between the copper clamps and the battery terminals dry and clean
  2. Place a penny close to each battery terminal which would cause leaks to steak to the penny instead of the terminals
  3. Do not fast-charge the battery as it causes the battery to overheat
  4. Do not make use of the battery when the engine is off
  5. Use coating products such as corrosion protecting spray or gel, Dielectric grease, Vaseline, or any petroleum jelly to create an additional layer of protection for your battery terminals
  6. Clean up terminals with diet coke
  7. Reduce the frequency of driving short distances

If you adhere to the steps outlined above as car battery corrosion prevention tips, you will be setting yourself up for longer car battery life.

Final Thoughts on Car Battery Corrosion

Most times, car battery corrosion is synonymous with an aging car battery that has begun to develop terminal issues. If after you have cleaned up your car battery and you notice the corrosion still building up, it is a sign that your car battery is old and there is need to purchase a new one.

Do not treat the matter of car battery corrosion lightly. It may present itself as a stumbling block when you need to accomplish a task and your car is refusing to start. In more severe cases, a corroded battery can lead to serious health implications due to explosion and exposure to harmful chemical substances.

Remember, if the corrosion continues to build-up after you have applied the tips I have shared on how to fix car battery corrosion, see a professional or get a new car battery.