hi guys, after several successful flights my phantom 2 vision took off on me today apparently to the last place it thought was home. i managed to do it by having the right switch down so it went up and over until out of range and then i realized i had hot set home properly. the direction it took off was directly to a prior home about 2.2km away. two questions: how far will this unit fly on a brand new fully charged battery in a 5-10mph wind? what happens when the battery runs out? I am trying to gather enough info to make a good guess on where it might be as the terrain is very challenging thanks!