I tend to fly my batteries to 3.8v/cell, which allows me time to fly, goof around, and then go, "Ok, time to come down," and if I have to wait 30 sec. or 1 min. more because someone's slow to clear the runway or there's a crash that has to be cleared, I can circle and come around again while they're clearing. It's just one of those safety factors I've built in, and something that the club instructors have suggested time and again. It's come in handy a couple of times, so that I'm not going, "Guys, if you don't clear the runway SOON, I'm going to have a dead stick electric crashing in the middle of the runway!"