I have an F550 and here's the equipment: e3000 system Naza M V2 Mini iosd Cam bus Immersion 600mw Tx Zenmuse Hd-2D and GoPro Aeroxcraft landing gear Spektrum AR8000 Zippy 8000mah 4s So after doing some math it's looking like I'm getting about 9 min of flight time to a pack. No crazy flying just normal. I'm landing at around 14.6v (or a reading of about 3.6 per cell.) I might try a few different batteries in the coming months to see if I can increase my time any. I don't have a good scale but it seems the bird weighs in at about 6lbs. Any suggestions are appreciated. Thank you.