It is a simple circuit that can be controlled for zero current drain and using a little trick with a PNP transistor sense when the battery voltage is above a certain point and I thought I could see a way to do it simply but some what inexpensively with about 5 parts with the same accuracy as the A/D... The point about the regulator was more rhetorical than anything else because I thought You had overlooked the 5V reg quiescent current and how much it can ramp up at higher input voltages and be overlooked as one of those "Page Three" things, I've been bit by that one a time or two in the past and I learned to read all the data sheets of the design proposed devices first before I began assembling them as an entity or better before I created the first approximation of a design as a schematic proposal for consideration as required. That's All.
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