extra hour for what - above the alkaline ?,extra hour to internal battery?
about the rechargeable alkalines , i know what are you talking about but i dont think they hold more the 10 charges
about running time , some one have to check what is the minimum voltage the microtrack have to see , if it more then 4.8 you have problem to run nimh batteries without step up converter to 5 v
the alkalines start at 6 v with lower capacity and fast dropping , to use them until the end you need voltage regulator as well , as soon they go under the minimum
with 4 2500 nimh and step up converter you have to get 65-70 % of what you get from non rechargeable lithium ion which stay 1.5 v all the way ( total 6v before step down)
The 2500 mAh NiMH in the USB battery box gave me a total of 4 hours WITH my lame internal battery, which on its own does 3 hours pretty consistently.
The Sundance Solar product claims 100 cycles, not 10. The Gadgeteer-reviewed recharger of ordinary alkalines has only been tested by them for a few cycles, so I don't know on that one.
For regular alkalines, I have gotten 5 hours now (including a charged internal battery that runs 3 hours on its own), the state of the meters leads me to guess I'll get a total of 6-7 hours or so.
How big is the step-up converter package? The niceness of the USB battery box itself is than it is about as small as a 4 AA package can get. I'd be interested in a small package USB box using NiMHs, for sure.
Jeff