Re: Storing calculator Message #11 Posted by Dave Shaffer on 7 Sept 2001, 12:29 a.m., in response to message #10 by Vieira, Luiz C.
I recently rejuvenated an HP35 that had not been turned on for probably 20 years. It had been stored (that's a fancy term for lying around in a drawer somewhere!) without the battery pack installed. I made a new battery pack with the recommended Panasonic cell phone battery (see elsewhere in the MoHPC), and it seems to charge up OK with my old HP power pack. For the first few minutes of its new life, the calculator displayed all the decimal points (a signal of low power, I think), but after that, except that the battery connections aren't as tight as you might like (I made a pretty ad hoc set of connectors), it works fine - either on the battery or the power pack. (The decimal point key is a little flakey after 38 years, but so are we when we get that old.)
I, too, was a bit worried that any electrolytics might have gone south in all those years, but that doesn't seem to be the case. As far as I can imagine, except for batteries, there is nothing else in there that should slowly fail with old age. (My Heathkit (another sad story) digital clock, from 1966, is still working fine, with its neon segment displays. Solid state equipment really does last almost forever if not mistreated.)
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