How to clean corroded battery terminals with DIY solutions, by USA TODAY on YouTube. 2 min 10 s.
- Video length
- 2 min 10 s
- Time to do it
- 20 minutes
- Difficulty
- Easy
- Steps
- 9
What you need
Steps
Park on a level surface, turn off the engine and remove the key. Put on safety glasses and rubber gloves before you touch the battery.
Look at the terminals. White or blue-green crust means corrosion. Note which cable is positive (red, marked +) and which is negative (black, marked -).
Loosen the negative clamp bolt with a wrench and lift the cable off the post. Tuck it aside so it cannot spring back and touch the post.
Loosen and remove the positive clamp the same way. Keep the two cables apart so they cannot touch each other.
Mix two tablespoons of baking soda into a cup of water. Dip an old toothbrush in it and scrub the posts and the inside of both clamps until the crust is gone.
Wipe everything dry with a paper towel. Check the posts and clamps for cracks or heavy pitting and replace any part that looks damaged.
Reconnect the positive clamp first and tighten the bolt. Then fit the negative clamp and tighten it. Do not overtighten the bolts.
Coat both posts and clamps with a thin layer of petroleum jelly or terminal protectant spray to slow new corrosion.
Start the engine to confirm the battery has a good connection. If the car still cranks slowly, have the battery and charging system tested.
Tips and common mistakes
Always disconnect the negative cable first and reconnect it last to avoid shorting the battery with your wrench.
Never let a wrench bridge both battery posts at once, since that can cause sparks, burns or a battery explosion.
Skip the baking soda on a sealed AGM battery if any liquid could drip inside, and use a dry brush instead.
Rinse away any baking soda paste with a damp rag and dry the area, since leftover paste can keep attracting moisture.
Questions
Can I clean the terminals without removing the cables?
Yes. You can scrub the posts and clamps in place with a baking soda paste and a brush. Removing the cables gives a much better clean, but disconnect the negative side first if you do.
What causes the white crust on battery terminals?
It is usually corrosion from battery acid vapor reacting with the metal. A loose or dirty connection makes it worse, so check that the clamps are tight after cleaning.
How often should I clean the battery terminals?
Check them every few months, or whenever starting sounds slow. Clean them as soon as you see crust forming so it does not spread to the cables.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
