DJI marketing battery blather talks about "getting up to 31 minutes of flight time" on a single battery. Is anyone getting 31 minutes- or even close to that? My experience is closer to 20 minutes or so as I never fly my batteries to complete depletion. You know straight off that 31 minutes is wishful thinking at best. But I've never even come close. I don't think I could milk 25 minutes out of it on a good day.