What is this mucky gucky yellowish crap on my battery terminals?

[Dela]

I keep gettting this gunky build up on my terminals - it's yellowish, and gunky/snotty..

What is it?

[teecro]

Corrosion....

Take your connections apart one at a time and deep clean starting with a baking soda and water bath, scrubbing with a wire brush and making bright with very fine emery cloth. But if you have build up of corrosion anywhere in the battery compartment the green goo of battery death will return...

[Hecky50]

Also, try being a little neater when you add water. Dry up any spills.

[JohnnieB]

As mentioned, it is corrosion and it forms on the terminals of batteries that have not been overflowed as well as those that have.

Disconnect the cables and clean the batteries and cables connections with a baking soda solution to neutralize.

Use a battery terminal protectorate of some kind when you reconnect the cables. Coat all exposed metal on the cable lugs and battery terminals.

The air in the battery compartment is corrosive, so the goal is to prevent the metals from being exposed to the corrosive air.