Corrosion on car batteries can make the vehicle increasingly difficult to start, until it won’t start at all. The corrosion appears as a white or green build-up around the terminal posts--the posts on the top or sides of the battery, where the cables connect--and as a black build-up on the posts themselves. Protect the car battery posts from corrosion by simple maintenance with minimal investment of time and expense.
Disconnect the battery cables from the terminal posts. Disconnect the negative (-) cable first and then the positive cable (+).
Open the water reservoir located on the top of the battery, unless it is a no-maintenance battery, which does not require additional water. Fill with water to the fill line because batteries that are low on water corrode quickly.
Mix a solution of equal parts baking soda and water. Use a toothbrush to scrub the corrosion off the battery casing and the terminal posts while taking care not to get any of the solution into the vents on the top of the battery.
Clean the corrosion off of one terminal post at a time, using a stiff wire brush, sandpaper or steel wool. The posts are clean when bright metal shines through.
Clean corrosion from the metal connectors at the end of each battery cable. These metal connectors fit over the battery posts. Scrub the inside of each one with sandpaper or steel wool until bright metal shines through. Clean the outside of the connectors with the baking soda solution. Inspect the battery cables where the metal connectors attach and replace the cable if white or green corrosion appears in the copper wiring of the cable itself.
Purchase “gray felt battery post corrosion inhibitor washers,” available at auto parts stores, to protect your car battery posts from corrosion for the long term. Fit one washer over each battery post before re-connecting the battery cable connectors. While this step is optional, it is very beneficial.
Coat each terminal with petroleum jelly or any of a variety of corrosion inhibitor products available at auto parts stores, and re-connect the cables. Connect the positive (+) cable first, followed by the negative (-) terminal.
