well i just did the other battery pack and after 2 mins i could hear it really decrease in the sound the roto makes, but it still lifts the heli off the ground at about the same throttle input?? how hot do the esc normally get? i took it outside again and it seemed fine untill the battery got low. if i don't have to use esky,and if i do really need another one(i mean i'm just hovering for like 5 secs at the most a foot off the ground) my local hobbystore prob has one i could buy. i know they carry eflight stuff if that will work. i still don't understand how it still lifts up and scoots on the floor just as easy, even when i hear the speed decrease. maybe its just because i'm in the house surronded by walls that it just sounds louder in here than outside and its a normal decrease just from all the fresh juice of being fully charged? i dunno