Converting HP-25 to NiMH batteries, possible?

[BobVA]

(07-26-2022 04:02 PM)cubytus Wrote:  ....As for the polarity, I wrote it on the inside, but soon found out it was moulded in the plastic. I'm still a bit puzzled by its awkward positioning. Did HP first design the holder in two parts for disposable batteries, then glued them together around rechargeable ones?

Nice find!! I must have re-cell'ed a zillion of those things and never noticed that molded in polarity marking!

Rechargeable batteries were pretty much expected in "professional" calculators, so I'd be *very* surprised if HP ever considered a disposable AA pack for the the Woodstock series. I think those marks are for the assembly workers.