The risks of charging a car battery while still connected

The process of charging the battery is often needed, although it is not necessary as long as we take out the maintenance and battery charging system regularly and adequately. Many methods are often used to charge the car battery, but it all depends on the battery type set and the charging device used.

The best way to charge the battery is to remove the battery from the car, open the battery cover and charge it according to the capabilities of the battery charger it has.

But sometimes, because of the rush to finish it quickly and because it's easier, many people charge the battery while still connected to the car.

charging a car battery while still connected

According to my experience, charging the battery while still connected brings more negative effects including car battery not charging. Many bad things can cause further problems with expensive repair costs.

So what are the risks of charging the battery while still connected to the car? Check out the three risks of charging the battery without removing the cable in the car below.

1. More risk of short circuit

The first risk of charging the battery while still connected to the car is the possibility of an electric short circuit in the car that damages other electrical components, creates sparks, burns, and other bad things.

Here are some conditions that often cause electrical short circuits and the risk of damaging the car's electrical components:

A. Short circuit due to the reversed battery polarity

Reversed polarity can happen when the minus charge cable is attached to the plus battery, and the plus charge cable is connected to the minus battery.

It can damage the Engine Control Module (ECM), Transmission Control Unit (TCU), and many other electric control modules. Also, it makes the car electrical system to fails.

B. Short circuit due to charge cable hitting the battery bracket, vehicle body, or engine grounding.

If this happens, the most common thing is that the alternator fuse for the charging system will blow and cause the battery to drain due to no charging from the alternator to the car battery.

C. Short circuit due to the wrong charge voltage setting

If your battery charger has a voltage choice that exceeds 12 volts, then incorrectly setting the charge voltage can also be a risk.

Because the risk of damage is quite significant, it is better to charge the battery by removing it from the vehicle.

To avoid resetting audio and others, installing a memory saver on the device is a good idea, or providing jumper cables and other batteries before removing the battery from the car so that these components can still function normally.

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2. The vehicle body can be exposed to lead acid battery water

If the battery used in your car is a wet-type battery, then to charge the battery, we need to open the car battery plug cover. Opening the car battery plug cover will release moisture during the charging process.

It is very dangerous if the battery plug cover stays closed during the charging process. Especially if the plug cover ventilation is closed and clogged, it can cause the car battery to bloat, and even if the pressure is too intense, it can cause lead acid leakage until the battery explodes.

This condition causes the car body to be more susceptible to exposure to lead acid battery water, which can make the car body rust and damage. Therefore, to prevent the car body from being exposed to the lead acid battery water, it is highly recommended to charge the battery by removing it from the car and charging it in a place with good airflow.

3. Takes more time

The last thing that becomes a risk if we charge the battery while still connected to the car is it takes longer than charging the battery removed from the car. Read: How long does it take to charge a car battery? It can happen because the attached cable will drain the electric power it should fully use for battery charging.

As a result, the amount of electric current needed for charging will decrease due to flowing elsewhere through the attached cable, so it will take longer for the car battery to be fully charged.