How to Disconnect your Car Battery

Step by step
How to Disconnect your Car Battery

Your car battery is the powerhouse for your car’s engine and electronic functions. Sometimes, it is required that you disconnect this to be able to perform certain repairs. Follow our quick guide on how to disconnect your car battery to find out exactly how to do this.

Safety first

Photo of a man wearing safety goggles

Putting on a pic of safety goggles and a pair of gloves as a precaution is a good idea before starting this procedure. The battery contains a large charge of electrical power as well as some potentially corrosive agents which are also flammable. The chances of anything going wrong are very slim, but it is always better to be safe than sorry. If you are wearing any metal or rings, be sure to remove these as well. 

Turn on the ignition

Photo of a car ignition operated by pushing a button

This is what happens when you turn the key in the car without starting the engine, and also works as a second safety precaution when disconnecting your battery. Some cars have automatic ignition, so, if you are unsure, check your user manual for clarification on your particular model of car. 

Locate the negative terminal

A car battery

This should be on top of the car battery and will be marked with a black cap and/or a small “-“ (negative) sign. This terminal should be disconnected before you disconnect the positive terminal. You will have to loosen a nut using a wrench, potentially with an extender to reach it. Turn the wrench in a counter clockwise movement until the nut is loose and pull the negative connector cable out of the battery. Put this to the side so that there is no chance of it connecting with the battery while you work on the engine.

Repeat for the positive terminal

A white Toyota car with the hood up, showing the engine

The same procedure should be followed with the positive terminal, but do take extra care that this cable doesn’t touch any metal as it still may be holding a residual charge. The positive terminal is usually marked with a red cap or a small “+” (positive) sign. 

Having problems?

A vintage looking engine inside the body of an orange car

Not many, but some cars have special battery fixtures which require specific battery cable removal tools. You can consult your local mechanic or go to an auto parts shop to find the right equipment if this is the case. Don’t try to use any other substitute tools as you may damage the battery or the engine of your car. 

Remove the battery

A boy wearing red doing repairs to a car

While this isn’t always necessary, sometimes it is helpful. Ensure the connecting cables are clear of it before you unscrew the brackets holding it in it’s tray and lift it straight up out of the engine. Batteries can be very heavy, so take care. 

Once you have disconnected the battery, you can continue to perform your repairs. If you are disconnecting your battery so that you can change it, ensure you clean the connecting cables with an old toothbrush and some diluted baking soda mixture and are then dried before connecting them to your old new battery, and ensure that the old battery is correctly disposed of. 

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