Voltage questions, i have a home built controller that runs for exactly 2:25 hrs whether its on a (1) 12v 1300ma battery, or 2 12v 1300ma batteries (doubling the ma) or a 9.2v 3800 ma battery. my goal is to get to 3.5 hrs. my draw is 640-670 ma depending on load.

how do i extend the lfe time of the controller?

thanks in advance