I'm surprised Roger the Skiffler hasn't beasten me to it, but I have my grandad's old Ever Ready portable radio: it's about thesize of a quite small attache case, complete with handle; to turn it on, you open the lid (which contains the loop aerial). It had two batteries: a 1.5V for the valve (US: tube) heaters, and a 90 -- yes, ninety V for the main power. They heater battery comprised about six C-size cells (Ever Ready size U2) soldered together, in a card container with a little socket on top to plug the heater lead into. The 90V job was even bigger; it was made up of lots and ts of those littel flat cels ypu find in you take a 9V battery apart. You can get a shock from around 70V, so it wasnt a good idea to take one of those apart! The two cost (I think) around two or three pounds back in the sixties; that would be maybe £10-£15 today? They lasted a long time, though. Around 1970, someone gave me a mains adaptor, designed to power valve portables; a good job, because you can't get the batteries any more.

Roger will no doubt give us some reminiscences about taking the accumulators to be charged...!

Steve