How Low Can You Go? 11C and 32SII Battery Voltages

[Dave Shaffer]

My wife has a pair of 32SII and an 11C. She claimed a couple of them (and we've now mixed up which was which) were either not working at all or acting "funky."

One of the 32's wouldn't turn on when I got it. I replaced its batteries with fresh LR44s, and it works fine. The other 32 battery voltages were all above 1.5 V, and it seemed to be fine, as well (and was probably the one that was not being complained about).

I then checked the 11C, which seemed to working OK this morning (after resting for a couple of days), and it seemed to be working OK, too. I checked its batteries, though, and two them were at ~1.33 V and the other was at ~1.22 V. That seems rather low, but the 11C (and siblings) are legendary for their long battery lives. So, I put the old batteries from the non-functioning 32SII (which were reading about 1.47V under no load) into the 11C, and it works fine (and the display may be a bit crisper).

So, I will retire/recycle the old 11C batteries, but wonder

1) How low can Voyager batteries go, and still provide reliable service?

and

2) How low can the voltage be for reliable 32SII functioning? I was a bit surprised that at 1.47 V the calculator did not seem to work.

[damaltor]

I switched the batteries in my 11c just a few days ago. two were at 1.3 and 1.4, the third was corroded and down do about 1V.
It started acting funky, but it is overclocked so it might have worked well with that voltage in original speed, i will never know

[gfbci]

Just over 30 years ago, my HP 15c was an indispensable tool for calculating coordinates when working on a lathe or mill. After a few years of work (followed me since college), still with the original batteries and a few days with the asterisk warnings, she stopped. At the time, I didn't even know where to buy these batteries, here in Brazil they were uncommon in the usual stores. As the work could not wait, I looked for alternatives to continue and realized that only one of the three batteries was exhausted. Quickly replaced with an M5 nut, my 15c came back to life with two good batteries and I was able to finish the job. I'm not one bit proud of this solution, but my admiration for my brave calculator only increased. My old 15c doesn't exist anymore, but I could confirm that two good batteries are enough to run a Voyager.

Gianfranco