How to Clean Corroded Battery Terminals in Your Car

Starting your car can be a challenge at times, with issues arising from the car’s core components. However, often the problem is caused by corrosion on the battery terminals. Learning how to clean these corroded terminals will save you both the expense and unnecessary worry.

Identify the size of the battery terminal. There are two types:

• If the terminals are located on the sides of the battery, you will need to use an 8 mm wrench to loosen the two nuts.
• If the terminals are located on the top of the battery, use a 10 mm or 13 mm wrench.

Make sure your car's engine is turned off. This will reduce the risk of accidentally grounding the electrical cable.

Loosen the nut on the cable clamp at the negative (-) terminal. Completely disconnect this cable from the battery terminal.

• Repeat the same steps for the clamp at the positive (+) terminal. If you encounter any difficulty detaching the cables, try twisting and pulling them simultaneously.

Inspect the battery for any cracks that could cause acid leakage. If you find any signs of damage, replace the battery.

Check if the battery cables and clamps are damaged. If you discover any significant tears, replace them immediately.

Mix one tablespoon (15 ml) of baking soda into a cup of warm water (250 ml). Dip an old toothbrush into this solution and scrub the battery terminals to remove any rust or corrosion.

• You can also dip the ends of the battery cables into the warm water to eliminate corrosion buildup on them.

Use a toothbrush to clean the battery terminals and clamps. Ensure that the toothbrush is sufficiently dipped in the baking soda solution.

Rinse the battery and cables with cold water. Make sure to wash away all the baking soda and rust. Dry the battery and the cable ends with a clean cloth.

Lubricate all exposed metal surfaces on the terminals, posts, and clamps. Use a lubricant oil or a commercially available battery terminal spray.

Reconnect the positive (+) cable clamp to its respective terminal. Use a wrench to tighten the nut.

• Repeat the same with the negative (-) clamp. Check the tightness of the terminals by gently twisting them by hand.

Keep a pair of gloves and a wrench of the correct size in the trunk or back seat of the car.

Use a wrench to loosen each terminal. Do not remove the cables completely.

Pour Coca-Cola onto the battery, starting from the center and moving outward. Repeat this motion in the opposite direction.

Let the Coca-Cola sit for 2 minutes, then rinse it off with water. Tighten the terminals and attempt to restart the car.

• You can purchase a battery cleaning spray. Some sprays contain acid-detecting ingredients in their formula. They often save time, but you should read the instructions on the bottle as each type has specific usage guidelines.
• If the rust is severe and cannot be removed with a toothbrush, you can use a battery terminal brush or sandpaper instead.

• The negative cable must always be removed first and attached last to prevent an arc discharge.
• Remove all jewelry before starting the work. Rings and bracelets can become grounding conductors or get caught in engine parts.
• Always wear protective equipment.

• Safety goggles or protective glasses
• Rubber gloves or nitrile gloves
• Wrenches: 8mm, 10mm, 13mm
• Toothbrush
• Baking soda
• Water
• Cup or bucket
• Battery terminal brush (optional)
• Lubricant or a battery terminal protector spray