Corroded terminals can kill your car's battery while it's still in its prime. If you want to keep this from happening to your battery, it just takes a couple of minutes of work a few times each year. Repeat these steps every time you get an oil change so that it will be easy to remember.
Pour approximately two tablespoons of baking soda into a small dish.
Gradually add small amounts of water to the baking soda while stirring it with a spoon. When it becomes a fine paste, stop adding water.
Take the bowl of paste and a paper towel out to the car. Open the hood and remove any covers you might have on the battery or cables to expose the terminals.
Dip a corner of the paper towel into the paste. Use the paper towel to apply a layer of paste to both of the battery's terminals. Apply another layer of paste to the terminal connections on the battery cables.
Replace the battery and cable covers if there are any. Close the hood.
