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How To Clean Car Battery Terminals: The Complete Guide

Make This Easy Six-Step Process Part Of Your Regular Car Maintenance Routine

how to clean car battery terminals

Batteries are an important part — perhaps one of the most important parts — of a running car. Without a functional battery, your car is practically useless. Keeping your car battery in good working order means you should know how to clean car battery terminals.

Battery terminals are found on the end of battery cables and are used to connect the cables to the battery posts. If they become dirty or corroded, you might have trouble starting your car. Or worse, they might damage your battery. Add these six easy steps to your car maintenance routine for how to properly clean a car battery terminal.

How To Clean Car Battery Terminals

1. Look For Signs Of Corrosion

The first thing to do is to look for signs of corrosion. If your car won’t start or if it struggles to start, it could be that you have a bad or corroded battery terminal. Another sign is any kind of electrical problems such as dimming headlights or your audio system fading in and out. If you are experiencing any of these problems, the best thing to do is to check under the hood.

The battery terminals are the part of the battery that connects the battery cables to the negative and positive battery posts. They could be the issue if there is corrosion on or around them. Look for signs of any powdery white or blue corrosion on the terminals or along the battery cable.

2. Gather Supplies

To clean the battery terminals, you only need a couple of products. The most important thing you need to remember is to wear protective gear. Safety glasses and work gloves are an absolute must. You also need a cleaning agent, a battery brush, a towel or two, and a spray bottle with water. A battery terminal protector will also help prevent future corrosion.

3. Locate Your Car Battery

After making sure your engine is off, the first step to cleaning the battery terminals is to locate the battery. Most batteries are located underneath the hood of the car. With some cars, the battery may be located in the trunk, but the majority are under the hood on the left or right side of the engine bay.

4. Disconnect The Battery Terminals

After you’ve found the battery, take the cover off the battery. Disconnecting the battery can be a little tricky. You should always remove the negative terminal first. If you have any questions, consult the owner’s manual for your car. You will need to loosen the clamps that connect the terminals to the battery posts in order to disconnect them from your battery.

First, loosen and remove the negative terminal. Then, do the same with the positive terminal. Avoid touching anything metal while handling the battery terminals. This is also a good time to inspect the battery terminals, battery cables, and battery posts to make sure there aren’t any signs of excessive wear or corrosion.

5. Clean The Battery Terminals And Battery Posts

The first step to effectively cleaning battery terminals is to pick the right cleaning agent. Though you can use a mixture of water and baking soda, we recommend a dedicated cleaning agent specifically designed to remove battery corrosion. Picking the right agent can drastically improve the speed and quality of the cleaning.

Once you’ve applied the cleaner to the battery terminals, rub in the cleaner with a battery brush. Make sure you spread it evenly over all areas where there might be corrosion. Scrub the terminals with the battery brush to remove any dirt, grease, or visible corrosion. You can also scrub down the battery posts using the battery brush to ensure you have a clean surface to reconnect your battery terminals.

Next, rinse off the terminals and battery using water in a spray bottle. Once clean, dry off the terminals, posts, and battery. After ensuring this is all dry, spray on the battery terminal protector to help slow future corrosion. Once you’ve cleaned and dried everything, it’s time to reconnect your battery terminals.

6. Reconnect The Battery Terminals

When you’re reconnecting the battery terminals, make sure you do it in the reverse order. Always reconnect the positive side first. Then, reconnect the negative side, and put on the battery cover. Once you’ve cleaned and reconnected the battery, your car should start up without any complaints.

6 Steps For How To Clean Car Battery Terminals

1. Look For Signs Of Corrosion
2. Gather Supplies
3. Locate Your Car Battery
4. Disconnect The Battery Terminals
5. Clean The Battery Terminals And Battery Posts
6. Reconnect The Battery Terminals

Frequently Asked Questions

What do the terminals on a car battery do?

The terminals on a car battery are the part of the battery that connects the battery cable to the battery post. They are the electrical contact point that connects the car battery with the rest of the car. When battery terminals become damaged or corroded, they can adversely affect the performance of the battery.

Can you clean battery terminals while the battery is still connected?

Though you can clean the battery terminals while the battery is still connected, it won’t be as effective as if you disconnect the terminals. It is always a good idea to disconnect the battery terminals so you can thoroughly clean the inside of the terminals as well as the battery posts.

Can corroded battery terminals cause a car not to start?

Yes, corroded battery terminals can negatively affect the battery to the point where your car won’t start.

Do battery terminals need to be replaced?

Battery terminals may need to be replaced if the metal is severely corroded. But at this point, your battery is going to be shot, and you will need to replace the whole battery. They usually last anywhere from 50,000 to 100,000 miles, but it depends on how many years you’ve had it and driving conditions. Your nearest mechanic or auto parts store can inspect your battery and determine if it needs to be replaced.

How can I tell the difference between the positive and the negative terminals?

The battery terminals are always labeled with either a plus sign (+) for the positive terminal and a negative sign (-) for the negative terminal. They can also be labeled with pos. and neg. Some batteries have color-coded terminals as well. The red cover usually indicates the positive side, and the black cover marks the negative side. The terminals are always labeled to help you to know how to disconnect and reconnect them.

About Haley Butterfield

Haley is a writer, reader, and life long learner. She recently graduated from Brigham Young University and enjoys spending time with family and friends. In her free time, you can find her reading the latest book, discovering new hobbies, or running in the desert.