Battery terminal corrosion is one of the top causes of no-start conditions, and it builds up so gradually you won't notice until your car won't crank one morning. The crusty white or blue-green powder is copper sulfate and lead sulfate — byproducts of the chemical reaction between the battery acid fumes and the terminal metals.
How to clean it
- Disconnect the negative terminal first (black cable), then the positive
- Mix a tablespoon of baking soda in a cup of water
- Scrub the terminals and cable ends with an old toothbrush dipped in the solution — you'll see it fizz
- Rinse with clean water and dry completely
- Reconnect positive first, then negative
- Apply a thin coat of petroleum jelly or dielectric grease to slow future buildup
Why it matters
Corrosion increases electrical resistance at the terminals. Your starter motor needs hundreds of amps to crank the engine — even a small resistance drop means sluggish starts, dim headlights, and strain on your alternator. Left unchecked, it can prevent starting entirely.
Quick action
Pop your hood and look at both battery terminals right now. If you see any white, blue, or green buildup, schedule 15 minutes this weekend to clean them. All you need is baking soda, water, and a toothbrush.
