Why Is My Car Battery Smoking?

Smoke from a car battery is one of the most common battery problems. You may see clouds of smoke emitting from your car hood. Sometimes you hear a hissing sound or find smells like rotten eggs. Whatever you experience, this is not normal for your battery to smoke. These may be indications of the battery problem. Then ask why my car battery is smoking.

A car battery is one of those parts of a car that keeps the vehicle on the road. But these batteries also become explosive or cause toxicity due to toxic smoke or evaporated poisonous acid. If you are at this risk, this article is for you. Here we’ll find out why your car battery is smoking and how to deal with the problems

What Does Car Battery Smoking Mean?

Before you find the reason for smoking, you had better know what does car battery smoking mean? Car batteries have the sulfuric acid solution as electrolyte. And we need to mix dissolved water to regulate the concentration of acid. 

In a car battery, smoking indicates overheating or overcharging. These let the battery materials react in an uncontrolled way. As a result, water and acid evaporate, and we find it bubbling or smoking, a mixture of boiled water and acid. No matter how it appears to us, there is a serious reason behind it.

Why Car Battery Smoking?

Some issues cause your car battery to smoke. Overheating, overcharging or combining both or faulty alternators are the most common culprits behind it. Let me elaborate on these issues


You may notice smoking in your car battery in hot temperatures on a hot summer day because of excessive heat. In this case, the electrolyte in your car starts boiling and evaporates due to the scorching heat of a summer day. While the evaporation reaches a climax, a cloud of smoke emits from your car hood. 

Charging at a hot temperature also causes these issues of smoking.


Overcharging can damage your car battery in many ways. Some of the battery chargers that go on charging, though fully charged, can cause a burning battery. After being fully charged, a battery emits gas due to excess electric energy. Sometimes Battery starts smoking when trying to jump-start also. 

When it’s overcharged, it produces more gas for chemical reactions. It may evaporate liquid elements in a battery which is found to smell like rotten eggs or sound of hissing while emitting. In the worst situation, overcharging generates heat and dries up the battery. Then it started burning itself or causing short circuits, sometimes explosions.

Faulty Alternator

In the car, an alternator is built to charge the battery while running. Its output should be within 13.7 to 14.7. But a faulty alternator can overcharge a battery that, which causes smoking. If the alternator fails to detect the change of the battery, its ongoing charge reaches the point of battery burning. 


Batteries are packed with corrosive elements in them. At the end of their life span, it gets damaged or leaked. Sometimes they are dried up uncarefully. These situations also create gas or smoke. 

The solution to Car Battery Smoking

Smoking Battery Acid is harmful to human health. You can’t drive with a smoking battery. Finding a way to stop your car battery is the solution to it. So, identify what makes your battery smoke at first. If it’s the temperature, try parking your car in a cooperatively cool area. Never park it in the sunlight. Don’t charge it in excessive heat.

You may find it overcharging. Then use a charger that regulates amperage and voltage. Try not to jumpstart your car. If you can’t find the cause and way of smoking, take help from experts or technicians.

Final Words

A smoking battery is dangerous. It’s flammable and emits poisonous gas. So you’ve to deal with the issue immediately and carefully. Taking care of your battery is the best way to deal with battery smoking issues. 

We’ve focused on the most common cause and ways of that issue. If you detect any one of them causing smoking, take care of it or take help from professionals. Take care of your car and car battery, and drive safely.

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