How To Disconnect A Car Battery

Czok > Blog > How To > How To Disconnect A Car Battery

Disconnect a car battery is one of the most fundamental things you need to be able to do when it comes to working on cars.

It’s really easy to do and I’m going to show you how.

I’m also going to give you the BEST trick for disconnecting battery terminals that may be corroded or won’t come off.


  • Socket set
  • Ratchet

Step 1: Turn off ignition

Ensure that you have turned off your ignition and removed the key.

Step 2: Locate the battery

Car batteries are usually located under the bonnet (a.k.a hood) but in the event that it isn’t it will most likely be in the boot.

Batteries are generally rectangle in shape and have positive (+) and/or negative (-) symbols on to indicate the different terminals.

If you are unsure where the battery is, check your owner’s manual or do a quick google search.

Once you have found where the battery move on to the next step that applies to you.

Step 3a: Open the bonnet

This again, is different for every vehicle but most of the time the bonnet release latch is located in the drivers footwell.

After your have released the bonnet,, your vehicle may automatically open and raise itself.

If it doesn’t, you will need to raise it with one hand and use the proprod in the engine bay.

Remember to consult your owners manual, it should tell you everything you need to know on raising the bonnet.

Step 3b: Open the boot

If the battery is located in the boot (a.k.a trunk), it may be hidden underneath or behind the boot lining.

Have a look around and if you can’t find it, check your owners manual. It will provide you with the information you need.

Step 4: Remove or loosen the nut/bolt

Always disconnect the negative terminal first.

The negative terminal is usually indicated by a negative (-) symbol. In the event that is isn’t the positive terminal (+) is almost always market too and often in red.

Use a correctly sized spanner or ratchet to loosen the nut/bolt securing the cable on the negative battery terminal.

If the nut or bolt spins whilst you are trying to loosen it, you may need to counter-hold the other side with another spanner or ratchet.

Step 5: Remove the cable

Remove the cable from the negative terminal.

What to do if its suck?

If you car is old, like mine, and hasn’t had the battery replaced or cleaned for a while. You may find that the terminal doesn’t want to come off.

Lucky for you, I have a solution.

What you’ll need:

  • Hammer
  • Flat head screwdriver

Step 1: Remove or loosen the nut on the terminal.
Step 2: Place the flat head screwdriver in the split of the clamp. (see image below)

negative battery terminal
Step 3: Hit the end of the screwdriver with the hammer.
Step 4: Try to remove the cable from the terminal.
Step 5: Repeat process


This is a basic bit if knowledge you should have if you want to become a mechanic or even if you just own a car.

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