THIS goes way beyond Shannon info.
This is world-overturning info, and I’m not kidding.
A 9-volt battery is simply a package containing six AAAA cells wired in series. A 6-volt lantern battery is simply a package containing 4 D cells wired in series.
This is like learning that wheels are really ice cubes painted black, or rocks are really elephants wrapped in foil.
All my life I thought larger batteries were single units, made by interleaving multiple layers of zinc and copper and electrolyte. I thought they were small versions of this old battery:
I not only thought this way, I taught this way. I drew batteries like this on the blackboard when I taught electronics.