I may be getting an HP-67 which is missing the batteries. Are these available anywhere? If so where do I get them. Can I use non-original Nicad batteries as replacements?
Hi Glenn,
Take a look here:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1321217825
They work great.
Arnold
Firstly, don't be tempted to try to run an HP67 (or HP65) from the AC adapter without a battery pack in place. You can damage the (custom) card reader sense amplifier chip. Which is only obtainable from another old machine.
The battery pack is just 3 AA NiCd cells in series. You could just wire up 3 cells and wire them to the contacts in the machine (the contact towards the display end of the machine is -ve). But if you don't want to modify your machine and want a drop-in battery pack, then it's a little harder to make one.
The battery packe are not available new any more, but it's possible to cut open old ones and fit new cells. I believe there are a couple of people who sell rebuilt batteries.