Actually, they do that a lot. That is how they make the larger sized batteries. You can open up one of those $20 batteries and find 20 AA inside of it...

excellent observation skills

First

:)

Powerbanks... not too useless, aren't they?

This exists!!

I've have said "battery powered battery charger"!

actually this could be helpful as an adapter of some sort...only have AAA batteries but need AA? Have no fear just put those tiny sonbitches in our AA adapter and get back to catching those pokemon -Jordan #ftw