The car battery functions to store electrical current that will later be used to supply the starter system, ignition, and car electrical system. This battery component can also experience problems, for example, the car battery becomes hot and causes it to swell. What causes the car battery to heat up? Here is the explanation.

1. Short Between Plates Inside the Battery

One of the causes of a car battery becoming hot is the occurrence of a short between the plates inside the battery itself. Each battery cell in a car has 2 electrode plates, namely positive and negative, inside it. 

Between these plates, there is an insulator, which functions as a separator between one plate and another. If the battery is used for a long period, the plates inside will undergo changes in shape. 

These plates become bent, and the battery fluid will also cause deposits and sediment. The bent plates and those deposits can cause the battery to become short or experience a short circuit.

The cause of the car battery heating up occurs because of the short, which causes the battery fluid to boil. As a result, the car battery body feels hot when touched. 

The condition of the battery being too hot should not be left unattended, as it can cause it to swell and become damaged, leading to problems when starting the car.

Read also: Vehicle Won't Start, Here's How to Fix the Car Starter Bendix

2. Using Incorrect Battery Water

The main cause of the short is the use of incorrect battery water, which will accelerate the rate of damage to the elements inside the battery itself. For example, if you use regular mineral water to top up the nearly depleted battery water. 

This is certainly not appropriate, causing a chemical reaction that should not occur, such as the short that causes the car battery to heat up. Because the acidity level and specific gravity in the battery water change.

3. Excessive Charging

Another cause that results in the battery becoming hot is over charge (excessive charging). Over charge usually occurs because the IC regulator in the alternator has problems. 

Generally, the normal charging voltage for a battery is between 12.7 volts and 14 volts. However, if the IC regulator has issues, the charging can be below or above that number.

If the charging voltage is below 12 volts, the effect is that the car battery runs out of electrical power or quickly discharges. 

Conversely, if the abnormal charging is above 14 volts, more air bubbles will appear, along with increased pressure and heat inside the battery. This is one of the common causes of car battery heating.

You should not let the above conditions continue to occur, as it will affect the lifespan of the battery itself. If the battery has swollen, is damaged, or is weak, it will ultimately cause you trouble. 

Because a weak battery can affect many other components, such as the electronic control system, ECM, and others.

Read also: 4 Easy Ways to Identify Car Battery Damage