How to disconnect a car battery ?

Sometimes you may need to disconnect a car battery for various reasons, ranging from simple car maintenance to full engine repairs. So, how disconnect car battery? Even though it looks difficult, disconnecting a car battery is quite an easy job, especially if you are already familiar with this.

However, because the car battery contains several chemicals, we still have to be careful even though the battery is dead.

Here are some precautions that we must consider before disconnecting a car battery :

It's better to read your car's owner manual before disconnecting a car battery. Some cars may need resetting the audio system or even the Engine Control Module (ECM) after disconnecting the battery.
Wear a safety goggle and gloves to protect your eyes and hands
Please turn off the ignition key and pull out, then save it near you. This action can prevent door locking when you connect or disconnect the battery terminal.

Then, follow this step on how disconnect car battery :

1. Locate the battery

The first step on how to disconnect battery is you need to locate the battery in your car. Most vehicles have the battery bolted in place under the engine hood. Some vehicles have their batteries tucked away out of sight in the trunk. You should open your car's owner manual to ensure that you know where the battery is.

2. Identify the negative terminal

The negative terminal has several special signs, so it's easy for you to recognize them. Here are some negative terminal signs

Covered by a black cover
The negative cable colour is black
There is a "MIN", or "-" sign nearby
The size of the negative terminal is usually smaller than the positive terminal.

Those are some common signs that you can find on the negative battery terminal.

3. Loosen the nut and disconnect the negative terminal

After you know where is the negative battery terminal, then we work to disconnect the negative terminal first. Why? In most cases, when we open the positive terminal first rather than the negative terminal, your tools may accidentally touch the negative terminal or the battery bracket.

It's dangerous and can make a short circuit to the entire electric car system. So, to avoid the danger that might occur, the safest step is to remove the negative terminal battery first.

Determine what size socket or wrench you need to loosen the nut on the negative terminal. Most American cars will usually need a ½", 5/16" or 3/8" wrench, while imports may require a metric socket or wrench.

Use the proper wrench or socket size to loosen the nut on the negative terminal, and then turn counterclockwise. It will take only a few turns to loosen it. Lift the terminal off the battery post and place it safely beside the battery. It's better to wrap it up to avoid accidental contact.

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4. Loosen the nut an disconnect the positive terminal

The next step is we need to disconnect the positive terminal. Positive terminal battery using large marked such as "+", or you can see by the red colour of the cable. Otherwise, the positive terminal battery has a large dimension form from the negative terminal.

Follow the same procedure to disconnect the positive terminal. Use the right size socket or wrench, then loosen the nut by turning counterclockwise. Lift the terminal off the battery post and place it safely beside the battery. Don't forget to wrap the terminal to ensure its safety.

Until this step, you have completed how disconnect car battery. You can safely perform repairs on the electrical components of the vehicle. If you need to replace it with a new car battery, it can be done in a few simple steps.

Unscrew the brackets that hold the battery in its tray. Some vehicles put the bracket on top of the battery, while others put the bracket next to the battery. Unscrew it then you can lift the battery straight up out of its tray.
It's better to clean up both battery terminals before installing the new ones.
Place the new battery on the tray and tighten the bracket
Connect the battery positive cable first, then tighten up the nut.
Connect the battery negative cable and tighten it up too.
Please make sure all bolts and nuts are tightened securely and check it once more. Read: How to do a car battery installation at home?
That's it. You have completed disconnecting and replacing your car battery.
Dispose of the old battery properly.