What are these spots on my battery??

[Ryedan]

I know these dark spots as well, tore off the wraps and analyzed them. No visible corrosion on the can, no liquid on wrap or can, no holes in the old wrap (tested in the dark against a light).

Yup, same experience here.

I concluded they're dark matter and am waiting for my nobel price anytime soon

You've got one vote from me. Good luck

 

[Mr. Relentless]

Probably tiny trapped air bubbles while getting shrink wrapped.