Can a user measure voltage with the 41-C series?

[Dieter]

(04-19-2015 07:17 PM)Garth Wilson Wrote:  I'm sure it's a simple comparator, basically a 1-bit A/D converter. When the voltage falls below the threshold, the annunciator comes on. (...)
My annunciator comes on at 1.2V, which would mean it would be on even for fully charged NiCads.

For the record: the BAT annunciator in my HP41s comes on at approx. 1 V per cell, which is the point where NiCds and NiMHs can be considered discharged. BAT does not appear with properly charged NiCds or NiMHs unless they are nearly depleted.

(04-19-2015 10:11 PM)4ster Wrote:  I've been checking state of charge with voltmeters, I was just thinking that being able to do that on the calculator itself would be useful.

You cannot check the state of charge of a NiMH or NiCd battery by determining its voltage. OK, if the battery is close to empty this might work, but else the voltage is nearly the same from almost-freshly-charged to almost-empty.

Dieter