Cleaning Corroded Battery Terminals: 14 Steps (with Pictures)

It has happened to almost everyone: a car that won't start. Sometimes it's a faulty part, but often this frustrating problem is caused by corroded battery terminals. Knowing how to clean corroded battery terminals yourself can save you a lot of headaches and costs.

Steps

Method 1 of 2: Cleaning with baking soda

Step 1. Make sure your car is off

This prevents the cables from being accidentally grounded.

Step 2. See how the poles of your battery are placed

There are two types.

• If the battery terminals are on the side, you will need an 8mm wrench to loosen the cable clamps.
• If the battery terminals are on top of the battery you will need either a 10mm wrench or a 13mm wrench.

Step 3. Loosen the negative cable clamp (-) nut

Disconnect the cable from the battery terminal.

• Do the same for the positive (+) cable. If the clamps are difficult to remove from the battery, try twisting them slightly while pulling them up.

  

Step 4. Inspect the battery for any cracks that could allow battery acid to leak out

If you see cracks, you need to replace the battery.

Step 5. Inspect the battery cables and terminals for damage

If you find a major crack you will need to replace these parts.

Step 6. Mix 1 tablespoon (15 ml) of baking soda with 250 ml of very hot water

Dip an old toothbrush into the mixture and brush the top of the battery to remove any corrosion.

You can even dip the ends of the battery cables in hot water to dissolve corrosion on the ends

Step 7. Scrub the battery terminals and battery terminals with the toothbrush

Remember to always submerge your toothbrush in the baking soda and water mixture.

Step 8. Clean the battery and battery cables with cold water

Remove the baking soda and corrosion residue with the water. Clean the battery and terminals with a clean cloth.

Step 9. Grease all exposed metal on the battery posts and battery terminals

Use petroleum jelly or a spray specifically designed to protect battery terminals.

Step 10. Reattach the positive battery terminal (+) to the correct battery terminal

Tighten the nut with your wrench.

• Do the same with the negative terminal (-). Check that the clamps are tight by turning them by hand.

  

Method 2 of 2: Cleaning in an emergency

Step 1. Always keep a pair of gloves and a key of the correct size in the car

Step 2. Loosen the battery terminals slightly with the wrench

Do not remove the cables completely.

Step 3. Pour Coke over the battery in a straight line from the inside out

Repeat in the opposite direction.

Step 4. Let the cola soak for a minute or two and then clean it with water

Re-tighten the battery terminals and attempt to start the car.

Tips

• You can buy a spray intended to clean batteries. With some brands, the acid is detected. These variants usually take less time, but you should always read the instructions on the aerosol can carefully, as each variety is different.
• Instead of a toothbrush, you can also use a battery terminal brush or sandpaper if there is a lot of corrosion.

Warnings

• The negative cable should always be removed first and reconnected last. This is to prevent sparks.
• Take off your jewelry before you begin. Rings and bracelets can be grounded, or they can catch on parts in the engine compartment.
• Always wear protective clothing.