Why AA, AAA, C, D? These are easily the most common 1.5 volt battery sizes, but why the strange letters? Where’s A? And B? Was there an A and a B but were phased out by the C but the A was replaced by AA but then needed another size between AA and C but B was already used so they went with AAA? Anyone follow that? This is the result of working 3rd shift…
Some info from the Master:
http://www.straightdope.com/classics/a4_005b.html
To add slightly to the confusion:
In battery powered tube electronics, the battery that is used to power the tubes filament is referred to as the A battery while the one used to supply plate voltage is the B battery. This convention disregards the physical size and voltage of the various batterys actually used.
So someone talking about tube circuits might refer to the B battery, but it’s not a B Sized cell.
I dug up some stuff on the size of the “B” cell, and the “A”, “B” and “C” cell conventions for old radios in a previous thread:
http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=116827
The B cell battery:
Off to Comments on Cecil’s Columns.
Clarification: the AAA battery is smaller than the AA battery. The more A’s, the smaller the battery.