On the GPS test, the current increases from 125ma, to 150ma... (before it goes into the weird mode)
Assuming its trying to do the same power, that means if it drew 125ma at 3volts. To draw 150ma, the batteries are down to 2.5volts, or 1.25volts per cell....
That appears to have occurred over a period of 90 minutes.
I have no idea where I'm going with this
To quote myself, it would seem, that for a Duracell CopperTop, to drop to 1.25volts, in
90minutes, it would require you to have a
350ma load or so.... not the 150ma they had...
In other words, I don't think the two tests were done with the same brand cells....
EDIT!
They've shown the current draw of the gps as being around 150ma.... based on the Duracell datasheet, you can extrapolate that, based on the 1.25volt "low battery" mode, that you'll get somewhere around 8 hours run time....
As to what they did?