I put a $10 voltwatch from Tower on everything I build, its cheap insurance, course I crash regularly cause I'm a bad builder/flyer anyway but not from a low battery,,,it did happen once, a friend was doing a maiden for me and it flew about a minute and then he yelled ,"I'm hit" and it went down, well after I found it and we checked that no one was on the same channel, he said man it acted like your battery was low.......Rog