As the battery in your car or light truck charges and discharges, it creates gases that escape through the vents in the top of the battery. As the gases escape, an acid residue also escapes and carries to the top of the battery. Over time, this residue builds up around the battery terminals, cable ends and battery tray. Removing the residue without damaging the battery takes just a few minutes and will restore the connection between the battery terminal and battery cable end.
Remove any plastic battery covers. In most cases, these snap into place over the battery. Some vehicles use a battery cover bolted into place and easily removed using a 10 mm wrench for most batteries.
Detach the negative battery cable from the battery. The three most common sizes of fasteners used to attach the cable to the terminal are 8 mm (most side post GM vehicles), 10 mm (most top post Ford, Chrysler and import vehicles) and 13 mm (older American top post battery design). Loosen the battery cable's end bolt using a wrench and twist the cable end as you pull it off the battery terminal.
Take off the positive cable end from the positive battery terminal in the same manner as you removed the negative cable. It is important to remove the negative cable first to avoid sparks that may ignite the gases that the battery gives off. Remove the battery hold down bracket using a 10 mm or 13 mm wrench.
Lift the battery out of the battery tray and engine compartment. Slide the battery onto a wooden block to prevent voltage leaks that may damage the battery. Mix a strong solution of baking soda and water in a cup. Spread the solution onto the battery tray and over the cable ends. The baking soda will neutralize the acid and prevent it from causing further damage. Allow the baking soda solution to sit until it stops bubbling. It may take several applications of the baking soda to neutralize the acid residue completely.
Scrub away any stubborn buildup of acid using an old toothbrush to work the baking soda solution into the recesses in the cable end. Rinse the battery tray and cable ends with water to wash away debris and neutralized acid residue.
Carefully brush the baking soda solution on the battery terminals. Be careful not to allow the solution to enter the battery through the vents in the top of the battery case. Allow the baking soda to neutralize the battery residue and rinse it away in the same manner used on the battery tray and cable ends. Wipe the battery tray, battery and cable ends dry.
Reinstall the battery into the engine compartment in the reverse order of removal. It is important to install the positive cable first to prevent sparks. Apply a dab of dielectric grease or other protectant to the terminal and cable ends after installation. Reinstall the battery cover.
