I'm new to droning. I've looked for this question on the forum but can't find it. I live at an elevation of 6.000 feet msl. The Batteries in my HS720E don't seem to last as long as they should. I haven't done a scientific test yet but I was thinking that maybe the higher elevation (thinner air) causes the little copter to work harder than it would at seal level. Does anyone have any info on this issue?