Interesting replies -- bottom line, the 50 percent rule is not hard and fast, and there is no magic way to convert working load to resting load, and don't worry so much about optimizing battery life.
I like it! This is sort of along the same lines as the old saying: "Since I gave up hope, I feel much better!"
Mex mentioned an amp/hour meter -- is there a good hand-held version of that, kind of like a multi-meter? I would want to use something like that on the road and also at home, so a hard-wired unit would be less useful.
