And the funny thing is, at a high load such as my GPS III+, those
alkalines
with their capacity diminished by the high current draw still last longer
than the NiMH that supposedly like high current draw. (I said the NiMH
compare favorably, not that they outlast alkalines.) I agree with you,
I've been playing aloud with numbers that don't always belong in the
same arena. And too many other factors impinge; I save money using the
NiMH in the GPS, but I'd kill them in flashlights that I routinely
leave on and forget. And then there are those sulfated wet-cell batteries
in the garage... *sigh*
==================
I had the same experience with my ancient Garmin GPS 40 ;alkaline batts held
longer than NiMHs.
Possible reason is that alkalines cells are 1.5 V and NiMHs 1.2 V
It is well possible that although the NiMHs are only considered discharged
when the voltage has dropped to below 1 Volt (per cell) this voltage (or its
multiple) is too low for the GPS to operate, whereas alkalines hold a higher
voltage for a longer period.
I noticed that when the GPS switched itself off when using NiMH batteries
,the cells apparently were not fully discharged.
Using an automatic NiCad /NiMH charger operating with an initial discharge
period as part of the overall cycle,
it took quite a while ,before the NiMH cells were discharged before charging
commenced.

Frank GMØCSZ / KN6WH