Which rechargeable battery you prefer for the HP-41?

[Dieter]

(08-24-2018 12:44 AM)Garth Wilson Wrote:  Are there any that give much over 1.2V per cell? Because that's where my 41's BAT indicator comes on, and that's a pretty standard voltage for rechargeable cells that are supposed to be 1.5V substitutes;

Both NiCd and NiMH cells have a nominal voltage of 1,2 V which is defined by the battery chemistry. Actually it is something between 1,4 V and 1 V (when completely discharged). The HP41 works fine with this voltage. The original 82120A battery pack had regular NiCd cells, and the system was designed to work with these.

If your HP41 really turns on the BAT indicator at 1,2 V this sounds a bit out of spec. It should be more like 1...1,1 V. Or, more precisely, a bit above 4 V for the whole pack. How did you determine that value?

Dieter