You\'ve got a lot of "I guess" and "I assume in there, Rich.
First he says his circuit draws 700mA at +/- 18V and he wants to run
for 10-12 hours before the battery voltage drops to +/-17V, and then
he wants to run at 600mA for 10 to 12 hours with no voltage drop at
all, which is bullshit.
He was given everything he needed to know early on.