Blue Powder Forming on the Car Battery Terminals? (How to Clean + Prevent it)

If you check the car battery regularly, you may find the bluish powdery substance forming on one or both battery posts.

If this gets you worried, then finding out what it is, and the best way to clean and stop it from forming in the first place will be of interest.

Read on to find out what this bluish powder is, why it forms and what you can do to clean and prevent it from forming.

Blue Powder – What is It?

The bluish powder substance that forms on some car battery terminals is copper sulfate, a by-product of the chemical reaction between the material of the battery posts and the electrolyte in the battery.

While it forms on many battery terminals, not all of them will have it. The bluish corrosion is usually linked to exposure of the terminals to the electrolyte possibly as a result of some physical damage or overcharging. Therefore, inspect the car battery for any damage that may be the source of a leak.

With that said, corrosion can form even when there is no leak on either the positive or negative battery connections.

The Dangers of Battery Corrosion

Depending on the extent of the formation of the powdery coating, the car may have difficulty starting or not staring at all.

Parsley Tips Turning White: What sh...
Parsley Tips Turning White: What should you do?

Additionally, the battery can fail to charge fully because of the lower current flow from the higher circuit resistance created by the powdery coating.

The bluish power coating interferes with the connection between the cable clamps and the battery posts affecting how well the car battery charges and how much current is available to power the car’s electrical system and start the engine too.

How to Remove it

To remove the powder coating, loosen the affected battery terminals. Sprinkle baking soda over the affected terminals and gently pour water over the baking soda.

It will dissolve the corrosion leaving the battery posts clean. Wipe the battery dry. Use a battery terminal cleaner to remove any remaining traces of corrosion off the battery posts and clamps.

Tips to Stop Corrosion

First, disconnect the clamps from the battery posts. Next, apply a battery terminal protector spray over the battery terminal posts and clamps, and then reconnect the battery clamp to the battery post.

You can also apply a coating of vaseline over the battery terminal and clamp to protect them against corrosion.

Related Questions

#1. Does Corrosion drain the Car Battery?

No, corrosion buildup does not drain the battery. It instead slows down how quickly a battery charges. The battery may appear to be draining faster yet in actuality fast it is because it is not being charged fully.

#2. What to Do: Bluish powder on the Battery terminals and Car unable to Start?

Remove the corrosion following the steps described here. The car may not able to start because of the additional resistance caused by the corrosion.

After cleaning the corrosion, attempt to start the car. If it fails, use booster cables and another car to start it or a jumper starter box.

Monitor the battery condition. If after charging the battery, the car struggles to start, the battery may be damaged. Arrange to have it tested at an auto repair center.

Closing Thoughts

Corrosion on the battery terminal connections forms when there is a chemical reaction between the battery posts material and the electrolyte in the battery.

You can use baking soda to remove it and a battery terminal protector to prevent the corrosion from building up again.

Recommended Posts

Leave a Comment