ORIGINAL: prole
Where do you get yours and are the re-chargeable or not.
I took a little time and figured out the circuit to get a 2.0Vout or 1.5Vout, pretty simple little thing, 3 resistors and a switch. If you have a drawing of the way yours is wired up I'd love to check my work.
Prole, They are, as William said, lead gel cells and rechargeable. I got mine from a friend who got the from a medical supply outfit. They were apparently a time-change item and were used, but free and good as new.
I would Google "Gates Batteries" and "2 volt gel cell". I have seen them somewhere.
I use a simple resistor that came with a 2 volt wet cell made (marketed) by Royal. . . maybe 25 years ago. I also use a long lead, maybe 4 feet long, made of good flexible extension cord.