How to Clean Corroded Car Battery Terminals

Difficulty starting your car can be caused by buildup on the battery terminals. Corrosion can form in and on the battery’s terminals and around the battery cable ends. Corroded ends won’t be able to supply power to the tools they have been connected to. You can extend the battery’s lifespan and improve its performance if you regularly check and clean car battery corrosion. Here are some tips on how to clean corroded car battery terminals.

What Causes Battery Corrosion?

Let’s look at the top 5 causes of car battery corrosion:

1. Overcharging

Overcharging the battery can push the electrolyte out of the vents or cracks, thus causing corrosions.

2. Reaction in Copper Clamps

The clamps that connect the wires and the battery are made of copper. Copper by itself is unable to corrode, but the current which overpasses through it produces copper sulfate, thus resulting in corrosion on the battery terminal.

3. Overfilled Battery

Overfilling the battery with battery water can cause corrosion on the battery terminal. As the battery terminal is made of metals, it can get corroded easily.

4. Electrolyte Leakage

Another reason making corrosion on the battery terminal is electrolyte leakage. If you don’t maintain the battery regularly, the electrolyte will leak out and accumulate on the battery terminals, causing corrosion.

5. Battery Age

Do not drive with the expired battery; otherwise, you will see corrosion on it. Replace the old battery with a new one.

How to Clean Car Battery Corrosion?

Cleaning with Baking Soda

1. Turn off your car.

2. Before loosening the nuts, determine the terminal configuration of your battery. There are two types.

  • If the terminals are on the side, you will need a 5/16-inch (8 mm) wrench to loosen both cable nuts.

  • If the terminals are on top of the battery, you will need either a 3/8-inch (10 mm) or 1/2-inch (13 mm) wrench.

3. Loosen the nuts on the negative (-) and positive (+) cable clamps.

4. Inspect the battery. If it is cracked or leaking, replace it immediately.

5. Another step is to check the battery cables and clamps for damages. You may have to replace them as well.

6. Mix 1 tablespoon (15 ml) of baking soda with 1 cup (250 ml) of boiling water. Sprinkle enough amount of baking soda powder to make a coat for terminals and the small area around the terminal as well.

7. Pour hot water on each terminal. After pouring water, the baking soda is reacting, and bubbles will appear ferociously from the chemical reaction.

8. Clean it properly with a toothbrush and rinse the battery and cables with cool water. Remove all the baking soda and corrosion. Dry the battery and clamps with a clean cloth.

9. Repeat the same procedure on cable ends.

10. Lubricate all exposed metal on battery terminals, posts, and clamps with a thin layer of petroleum jelly.

11. Reconnect the positive (+) and negative (-) cable clamps to the proper terminal. Tighten the nuts.

Cleaning with battery cleaner spray

1. After disconnecting all battery cables, use battery cleaner spray to spray on the battery terminals and the cable ends.

2. Leave the battery, and the cable ends in the spray for a few minutes. You may notice the color of the spray dissipates.

3. After everything, spray the cable ends and the battery terminals lightly once again. If you notice that the color doesn’t change or there is a slight change, this means the acid is neutralized.

4. Use water to rinse the battery entirely. Carefully clean spray off the car battery and the areas around it.

5. After rinsing with water, use a battery brush to clean the cable ends and the battery posts. Turn it at least 3 or 4 times around in order to remove all corrosion which is build up inside the clamp.

6. Spray the battery terminals with the battery protector or grease them with a thin layer of petroleum jelly.

7. Reconnect the car battery terminals.