If I remember correctly, we plugged the wireless directly into the battery with little red/black bakelite plugs; the bayonet was about 1/8" diameter, split. As NJ says, nothing exciting inside, just piles of rectangular cells; each a sandwich of carbon plate/sal ammoniac gel, the gas absorber in a paper sac, ( manganese-dioxide), and a zinc plate, with thin connecting strips up to the socket block. I seem to remember the top being potted in gas-pitch. The sub-assembled cell was usually held together by a crimped card edge strip, but the last versions I saw had polythene/pvc? crimps.
The wireless valve heaters ran off a separate 2v glass lead-acid accumulator, and before we got mains power in '52, I used to lug 2 of these 'occard lumps to the pub for charging each week. Cost, threepence (= 5 cents US) per acc, plus I got my pocket money when I returned, ( one and six = 30 cents US).
Sixpence for my National Savings Stamp, ( paying off the lease-lend ), a bottle of R. White's lemonade (tuppence-halfpenny), a Mars bar, a toffee-apple, some licorice, or how about a quarter of pear drops?, some jelly babies?, a packet of sherbet-dip perhaps? or a few pennies into my firework club card for November 5th. Ah! the pleasure, the anticipation, peeping over that sweet-counter to make ones choice, ration-ticket gripped like a vice.
And I must have squandered the rest!
Wood work but can't!