I tree'd my Evo a couple years ago and it spent a week at the top of a tree before I was able to get it down. A week in February. In Wisconsin. In snow, ice, sleet, rain, hail, wind, thundersnow, you name it for a week. When I got it down for some reason I impulsively tried to fire it up (the battery never got jarred loose) and it turned on and came to life. I took it home, took the battery out, spread it all out on a towel, turned a fan on it and let it thoroughly dry out for several days. Popped a new battery in it and it popped right off like nothing happened. I could have probably recalibrated everything and called it good and kept flying but I did send it in to have it gone over. They told me that the circuit board still had moisture on it and was starting to show signs of corrosion. So it was not a matter of if it would fail, but when. They sent it back and I sold it "as is buyer beware" for $400 and put that towards a new one.