This Oldham advert from June 1950 extols the virtues of their multi-voltage radio batteries.  Shows both the more up to date multi-output "dry battery" alongside an old style accumulator (acid battery) which was the radio battery from the 1920's.  An earlier advert from this series (in April) has a bust of Shakespeare with the strap-line of "Turn it H'up - a catch phrase of the popular Leon Cortez.  Another from May had a picture of a judge with the strap line "Sound Advice".

The modern portable battery has outputs for 12, 36, 60, 84, 108, 24, 48, 72, 96 and 120V.  Oldham & Son Ltd. was one of the few battery makers not to make portable radios (like Ever Ready and Vidor).  The marketing angle is obvious - what else is there to sell about batteries apart from their lifetime.

"Listening to Schubert's beautiful piece of work is delightful, but to hear one's favourite music fade and die is and 'unfinished symphony' of a different kind.  You can help your customers to avoid similar experiences by recommending Oldham Radio Batteries - the batteries with 'Power-to-spare' - and incidentally build prestige and good business."

What a beast - and of course impossible to source these days.  Collectors of portables from this era are condemned to taping together multiple modern batteries or building quite complex mains based battery eliminators.

Oldham Radio Batteries
Oldham & Son Ltd.
Denton
Manchester
Established 1865