How To Clean Battery Terminals
White or green corrosion on the battery terminals can cause poor starting. Cleaning them is simple if you disconnect in the right order.
DifficultyEasy
TimeAbout 20 minutes
AreaBattery and electrical
What you need
- SpannerFor the terminal clamps.
- Wire brushFor terminals and clamps.
- Gloves and eye protectionCorrosion is irritating.
- Baking soda and waterTo neutralise deposits.
Step by step
- Switch everything offRemove the key and check the manual for radio or alarm codes.
- Disconnect the negative clamp firstThen the positive.Wear gloves and eye protection.
- Clean with brush and soda solutionBrush the posts and inside the clamps until shiny.
- Rinse and dryWipe with a damp cloth and dry thoroughly.
- Reconnect positive first, then negativeTighten firmly.
- Protect the terminalsA thin layer of terminal grease or petroleum jelly slows new corrosion.
When to go to a workshop
If corrosion returns quickly or the battery case is wet, the battery may be leaking or overcharged; have it tested.
Questions about How To Clean Battery Terminals
Why do terminals corrode?
Acid vapour reacts with the metal, especially with loose clamps or overcharging.
Will I lose settings?
Some cars lose radio presets or need window and steering relearn procedures. Check the manual.