Expert Advice | How To Disconnect Car Battery – 7 Safe and Easy Steps

Here are the seven steps about how to disconnect car battery. There are some tips and tricks you need to know and be aware of. Still, the process itself is not rocket science.
how to disconnect car battery
How to disconnect car battery

I spent several hours researching and putting together simple and clear steps on how to disconnect car battery. As per our mission and goal at Car Care Handy, I aim to cut through the jargon and help you make the right decisions for your car care and maintenance.

Safety First

Car battery – Safety first

Disconnecting a car battery can be very dangerous if not done safely. You could get a small shock or even cause an explosion. So you need to be very careful. [1, 2, 3]

It’s recommended to conduct this procedure outdoors in an open space environment. This will protect you from getting exposed to too much dangerous gases.

Because car batteries are electrically charged, before you touch your battery, make sure you don’t have any jewelry on. The contact of the battery with metal can result in an electric shock. This is also the case with water. If you’re working on a damp area, the simple removal of the car battery can turn really bad. Be sure your working area is completely dry and covered.

It’s also advised to wear gloves and goggles before you start the procedure.

What You Will Need?

Disconnect car battery – What you will need?

Before you start the removal procedure, make sure to have all the necessary tools and materials required to disconnect the battery in time and without any damage.

Make sure you have an adjustable wrench or a socket wrench set in your toolbox. You’ll also need a wire brush either a cup-style wire cleaning brush or a pipe cleaning wire brush and heavy-duty shop towels. Baking soda and a water cleaning solution are also recommended for cleaning purposes. 

Make sure to have the new battery ready, if your goal is to replace the old one once it’s disconnected.

7 Easy Steps

7 Steps to disconnect car battery

Step 1: Shut Everything Off

If you’re driving, the first thing you need to do is obviously park the car and shut everything off. You’ll need to let your car cool down a bit before starting to disconnect the battery.

If you’re not driving, you need to make sure your car ignition is turned off.

Check to ensure that no electrical component of the car is running.

Leave the driver door open in case your car locks when you’re replacing the battery. 

Step 2: Open Your Hood

The hood is where the car battery is typically housed. Once your car is completely turned off, pop the hood open. You can open the hood either by pulling the lever or pushing the button that is typically located on the driver’s side underneath the dashboard or around the steering wheel area. If you can’t find it, check your manual to locate it.

Step 3: Locate Your Car Battery

The battery is located in the hood in most cars. Once you have your hood open, you can easily find it. It’s possible that your car battery is located elsewhere. Some vehicles house the battery in the trunk or somewhere in the rear. Refer to your car’s manual to find where to find the battery.

Step 4: Disconnect The Negative Terminal

Now that you have your battery right in front of you, you should start by locating the terminals. The negative terminal has a negative “-” sign, so you won’t miss it. The negative terminal should always be removed first to minimize the potential risk of explosions.

If the terminals of your battery are covered in plastic caps, make sure you remove the caps first. That gives you access to the cables and clamps to disconnect your battery.

Once you find the negative terminal, get your socket wrench or the adjustable wrench to loosen the nut that holds the cable to the negative terminal. Remove the nut completely and keep it in a safe place.

Don’t forget the gloves for safety operations. Once you disconnect the negative cable, put it as far away as you can from the negative battery terminal.

Step 5: Disconnect The Positive Terminal

The positive terminal has a positive “+” sign, so you won’t miss it. Again, if the positive battery terminal has a plastic cap cover, remove it and lay it aside safely.

Disconnect the cable from the positive terminal in the same manner you did for the negative terminal in the previous step.

When you’re removing the cables, make sure that your wrench doesn’t touch both terminals at the same time. This might result in an electric shock. You also need to make sure that the positive battery terminal doesn’t accidentally come in contact with any metal part on the car.

Step 6: Remove Your Car Battery

Once the battery terminals are disconnected, you can remove the battery. Note that batteries can be heavy, especially if you drive a big vehicle.

There might be some other mechanisms securing your battery in place. Some batteries are held by a clamp or steel strut. You need to find them and remove them. They might be located in the tray holding the battery. Refer to your car manual to make sure of it. Removing these mechanisms may require the use of a socket wrench.

Now, your battery is free. Lift it out of its tray carefully and lay it on a flat surface. Make sure it’s always in a flat position to reduce the risk of spilling the dangerous acid inside.

Step 7: Clean Your Car Battery Terminals

You might notice that the battery terminals have corrosion. This can happen if you haven’t disconnected the car battery in a long time. It’s nothing to be worried about, though, it just needs cleaning. And you can usually do that with things you already have at home. In fact, you can use a mixture of baking soda and water along with a terminal cleaning brush or even a toothbrush. 

Scrub the terminals with a bit of force to remove all dust and grime visible. Then spray water and use a cleaning cloth to wipe everything down. Once you finish cleaning and the battery terminals are clean and dry, use petroleum jelly. This will keep the terminals lubricated and keep them away from corrosion.

What To Do Next?

Disconnect car battery – What to do next?

Keep the battery or install a new one?

If your old battery is still good, you won’t need to replace it. Just lock it in place.

If your goal is to install a new battery, start installing the positive terminal first then the negative one. And never forget the safety measures.

Settings Changes

Once you have your battery in place, you might find the digital clock and radio settings changed. You’ll have to do a settings reset.

If the radio is locked when you start the car. You need to unlock it by entering the radio code. If you don’t have the code, you’ll have to consult a dealership to assist you. 


How to disconnect car battery – FAQ

What Are Symptoms Of A Bad Battery?

A bad battery is usually easy to locate. Just look out for the following symptoms [4]:

  • The engine is harder to start or doesn’t start at all sometimes
  • The engine won’t start even if the lights are on
  • Nothing on the car seems to work
  • Dim headlights or even not emitting any light 
  • Dim lights inside

Which Terminal Do You Take Off First?

The negative terminal always goes first when you’re removing them. It reduces the risk of sparks. But when putting the terminals on, the positive terminal starts first. 

Can I Just Disconnect the Negative Terminal?

No, you can’t just disconnect the negative terminal. For whatever reason you’re disconnecting it, you should always disconnect both terminals. And make sure they don’t accidentally touch.

The Bottom Line

The battery is one the most important components of your car. If it’s dead or can no longer hold a charge, it can leave you stranded in the middle of nowhere. This is why you should know how to disconnect it and replace it safely in place if it stops.

Whether you want to check your car battery or install a new one, you can follow the seven steps outlined above. During the whole process, pay close attention to all safety measures described and explained throughout this article.

Do not hesitate to let a professional assist you if you feel not comfortable with the process.

Do you want to learn more about charging your car battery? Check out our guide on how to charge a car battery.