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

[Sukiari]

(04-20-2015 01:35 PM)4ster Wrote:  

(04-20-2015 05:51 AM)Dieter Wrote:  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.


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

Good points. So, for those of you that run NiMH in your HP-41s, what is your battery cycle strategy given that the BAT annunciator is not really useful with this type?

While I don't own a 41 (yet, soon though!) I do use NiMH batteries in many devices and I find that *ALWAYS* having fully charged, low self-discharge batteries handy for each device is usually the way to go. Most devices will operate fine and won't show the low-battery warning until the battery is actually low with NiMH types, but you have precious little time to change them unlike with alkalines.

Many people are cheap and decide to get the regular, non-LSD type NiMH cells which lose 1/3rd or more of their charge each month just sitting there. I believe the use of these less advanced cells are the major cause for the rumor that all NiMHs perform poorly.