Step-by-Step Guide for Using WD-40 on Car Battery Terminals. Maintaining clean and protected battery terminals using WD-40 is a straightforward process that can help ensure optimal performance and longevity. Follow this detailed step-by-step guide to effectively clean and protect your car’s battery terminals, keeping them in top condition. Steps: Add 1 part (a tablespoon) of baking soda to 1 cup of water to make a cleaner. Use the pipe cleaning wire brush, dipping it into the cleaner, to clean the interior of the positive and negative connector cables in contact with the terminals. Use the cup-style wire brush to clean the terminals. Yes, It is totally safe cleaning car battery terminals without disconnecting. To ensure safety, turn off the ignition and spray on the hot water on the terminal, more like a jet spray. The pressure and the temperature of the water will equally contribute to cleaning and removing dirt and deposits on the terminals. In many cases, ignition problems can be fixed by cleaning the car battery corrosion from the terminals and cables, which couldn’t be simpler. There are several reasons why a car battery develops corrosion on the posts and cables. If you find yourself with this problem there is a simple, everyday solution and a very cool battery experiment you Since most car batteries are fairly accessible, regularly inspecting and dealing with corrosion isn’t a difficult automotive maintenance task. How Can You Clean The Corrosion? The simplest way to clean battery corrosion is with a wire brush. Remove the connections from each terminal and brush each clamp and terminal until the gunk has been Nov 15, 2009. #7. The best way to clean battery terminals, when corroded, is to use a baking powder and water mixture. Rinse off and spay with battery terminal coating that most car parts stores sell. The above suggestions probably coat the terminals just as well. Once you get corrosion, it likes to keep coming back. Next, remove your positive battery terminal. After removing the terminals, you can apply anti-corrosion washers or a small amount of dielectric grease on your battery’s posts. Another great anti-corrosion chemical is the AMSOIL heavy-duty metal protector, which can also be used to prevent rust. After you are done with the cleaning, connect Corroded Battery Terminal Symptoms . If your car battery terminals are corroded, you may notice one or more of the following symptoms: The engine is slow to start. The headlights are dim. The interior lights are dim. The power windows are slow to operate; The power locks are slow to operate. The stereo system sounds weak or muted. 2. Baking Soda/Water. Baking soda and water are commonly used to clean battery terminals and contacts. It’s simple to make and couldn’t be any easier to use. While it can be used with other electrical contacts, let’s look at the best way to use it with the battery terminals and connectors. Take a dry, clean rag and wipe the terminals thoroughly with it before connecting it to the vehicle. The rug should not have any oil or grease on it. Rub the terminals 2 to 3 times to ensure that these are completely dry. Do not use paper towels here. Paper shreds and remaining bits will stick to the terminals. B1JssT.