Sparesbox Blog

How to Disconnect a Car Battery

By Linda Quan

Thu Mar 25 2021

It’s a pain in the neck when you have a dead battery, and it’s an even bigger pain in the neck to pay someone at the auto shop to pull it out for you. Luckily, disconnecting your car battery safely (without hurting yourself or your vehicle’s delicate electronics) can be done right at home. Read on to learn how!


1. Identify the positive and negative terminals

Obviously, the positive terminal (usually red) will be marked + and the negative terminal (usually black) will be marked with a –. Why do you need to know which terminal is which? The reason is there is a special order you need to follow when disconnecting the cables for safety reasons.

2. Disconnect the negative terminal, followed by the positive terminal

Disconnect the negative terminal first, and THEN disconnect the positive terminal. Do not disconnect them both at once as this can lead to the battery exploding. It’s a good idea to wear safety gloves for this step, and you may find yourself needing a wrench to loosen any nuts on the terminals.

IMPORTANT: Do not let either terminal come into contact with metal (whether it’s on your tools or from the vehicle) as there may still be some remaining charge in the battery.  


3. Remove the bracket or strap holding the battery

Your battery is usually held down in the battery tray by a bracket or strap. Simply use your wrench to remove any bolts and once loosened, lift your battery out of the tray completely.


4. If you need to install a new battery, check the terminals and cables for rust.

To clean the rust off, simply mix a cup of water with one tablespoon of baking soda and use a toothbrush to scrub off the build-up. Once the terminals and cables are clean, dry off any remaining water before putting the new battery in the tray.

5. Reattach the terminals

When reconnecting a new battery, attach the positive terminal FIRST, followed by the negative terminal. Make sure the battery is strapped in and secure.


Congratulations, you’ve successfully removed your battery! If you’re in need of a new replacement battery, check out our huge range of Batteries & Accessories. From Batteries to Battery Chargers and Jump Starters, Sparesbox is your one stop shop for all your electrical needs.