I just removed the battery in the photo from a clock; as you can see in the photo, it's an alkaline battery.

When I grew up (in the dark ages,) dry cell batteries were carbon-zinc (I think,) and when one leaked, it caused damage to the metal parts that it came in contact with. I remember using moistened baking soda to remove as much of the leakage as possible and neutralize the acid (I think) in an effort to salvage the device. The white stuff in the photo looks very similar, but doesn't seem to do any damage. I picked and shook most of it out of the device it was in, and didn't see any reason to use baking soda.

What is the residue in the picture, and what was the residue from the carbon-zinc batteries? Thanks.

 

What is the residue in the picture, and what was the residue from the carbon-zinc batteries?

According to Wikipedia, the white gunk from alkaline batteries is potassium hydroxide; clean with vinegar. The white gunk from carbon-zinc batteries is (was?) zinc chloride; several places I saw say to clean it with baking soda.

 

Basically, carbon batteries use an acid and alkaline batteries use the opposite, a base.
My definition of a battery: Any two dissimilar metals in an ionic solution whose Ph is not 7.
That is a simplistic way to say it, but it works all the way down to electrolysis in a plumbing system.
Which metals and which solution is the whole of the science behind batteries.
A bit of Googling or one of our chemists can name exactly what's in there.
and OBWO did the Google part.

 

My definition of a battery: Any two dissimilar metals in an ionic solution whose Ph is not 7.

I gotta write that one down...

 

Thanks. I guess I should have googled before I posted.

 

And leaky alkalines are damaging. I've noticed they remove the conductive plating (tin, nickel?) from spring steel battery contacts, leaving rusted terminals in their place.