A whale fact is an interesting fact that may very well in fact only interest me. The genesis of the term is that I once read a book on whales and then inundated everyone that I knew with my new whale knowledge. But, I digress...
So, why are there no "B" size batteries?
Because they are obsolete. B-sized batteries were once used as component cells inside zinc carbon battery packs, used to power the filaments for old radios and crank telephones. But electronic equipment has gotten smaller, and the old B batteries are no longer necessary to power them, so they stopped making them.
(Answer via Yahoo! Answers)