SoundGuy, you are exactly right -- and even more so, there is the mysterious Peukert effect to think about, which would more than double my capacity.
But I am one of these belt and suspenders guys -- I use one battery at a time. The other is a spare in case the first one dies. If they are in parallel and one dies, I could be left without power. So they are independent. If and when the first one gets too low, I swap them. Due to my solar panel, I may never be forced to swap them again. This last month of boondocking, I swapped them every week, whether they needed it or not.
And red31, I take your point -- the resting periods of about half an hour may have extended the "run time." But this is sort of like the Heisenberg Uncertainty Principle -- the act of measuring something can alter the object being measured. (Didn't see that coming, did we??)
