How to Clean Battery Terminals
The Safe Way to Remove Battery Acid and Corrosion
Nobody wants to fall victim to a dead battery. Over time, the battery posts and terminals on a car will build up with a layer of corrosion. This build-up can mean problems for a car when a poor electrical connection develops between the battery cable and the battery. The battery can also develop cracks as a result of this corrosive build-up and emit hazardous and explosive gasses. Cleaning the corrosion will prolong battery life and prevent these car battery problems.
Parts & Tools RequiredTools:
- Battery terminal cleaning tool
- Wrench or socket set
- Wire brush
- Rubber, latex, or nitrile gloves
- Safety glasses or goggles
- Baking soda
- Bowl of water
- Rags or towels
- Optional: Battery terminal cleaner spray
- Optional: Battery terminal protectant spray
Before You Begin
Prior to starting repairs, it is wise to follow a few basic safety precautions. A car battery contains lead and sulfuric acid. The acid can cause severe burns if leaking from a damaged battery. Flammable hydrogen-sulfide gasses are also released gradually from the battery. Avoid touching the corrosion built up on the battery posts and terminals. Use personal protective equipment such as a pair of solvent-resistant gloves to protect your hands. Shield your eyes with safety glasses or goggles. Do not smoke while servicing a car battery. And be aware of anyone who might be in the area of your repairs.
Please read and understand this Legal Disclaimer.
Once you have ensured your safety you are ready to begin.
Clean off any loose debris with a wire brush.
Mix a tablespoon of baking soda into one pint (2 cups) of water to form a cleaning solution. Using a toothbrush, scrub the terminal clamps and battery posts to remove any corrosion, dirt, and grime. Dry with a rag or towel to remove dirt, debris, and cleaning solution.
Use a wrench or ratchet and socket to loosen the terminal clamps. Carefully twist the clamps to remove them from the battery post. Remove the black negative (–) cable first, followed by the red positive (+) cable. Disconnecting the battery may lead to the loss of settings in the navigation and stereo systems, as well as possible loss of data stored in the vehicle’s computers which can adversely affect vehicle operation. (See the article Electrical Issues After Replacing the Battery for more information)
Inspect the battery cables and terminal ends for signs of wear and corrosion. Also, inspect the battery and battery posts for damage. Replace any components as needed to prevent potential failure.
Using the cone-shaped end of the battery terminal cleaner, scrub the inside of the terminal clamp until it is clean, bare metal.
Some vehicles have terminals that screw into fittings on the side of the battery, rather than clamps that fit on posts. If this is the case, use a wire brush to clean the threaded studs.
Work the female end of the terminal cleaner onto the battery posts. Place the cleaner on each post and rotate back and forth until the posts are clean and bright in appearance.
Again, use the baking soda and water cleaning solution (or terminal cleaner spray) to clean the body of the battery. Remove any residual corrosion and grime with a towel or rag.
Starting with the positive (+) cable, reattach the terminal ends to the battery. Avoid excessive force and tighten the clamps until they are snug.
If you would like to learn how to safely jumpstart a car with a dead battery, see the article How to Jumpstart a Car.
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