How to clean car battery Terminals?
Open the hood and locate the car battery. loosen the nuts on the clamps using a wrench. Once loosened remove the negative clamp, marked with a "-" first. It is very important the order. Only after the negative clamp is removed, remove the positive clamp, marked with a "+". Combine 2–3 tablespoons of baking soda with a tablespoons or so of water. Stir to make a paste. Apply the baking soda paste to the battery connections. Be careful, although baking soda is generally safe, you should take care not to get it on other car components or on your self. Once the baking soda is applied, you will see it bubble and foam, as it reacts with the corrosion. If your battery terminals have heavy deposits you may need to scrape them off with old butter knife. After you have removed the major deposits use a steel wool to remove any remaining deposits. Rinse the connection using a little water. Be careful not to rinse the the baking soda paste into the battery vents, as the baking soda can neutralize the battery's acid and shorten the battery's life. Wipe the terminals clean with a dry clean rag. Add something hydrophobic, such as petroleum jelly (vaseline) or grease to the now cleaned terminals. This will help slow future corrosion. Put on the positive clamp first, then the negative clamp. Use a wrench to tighten if needed. Once the clamps are on, replace the rubber or plastic shields covering the clamp/terminal junction.