I recently bought an air 2s with standard remote. Assume they are bound out of box. I bought a air with smart remote from a friend of mine. Updated the SR and connected to my Air 2s for flight just fine. Went to do a second flight and get remote not bound to air s2 and have 4 flights left? Tied to bind and says bounded to another account. My question is does the original standard remote have to be unbound from air s2 or bind smart controller to it? Or is the smart remote bound to other air 2 aircraft and needs unbound before it can bound to my air 2s? Or is it bound to an user account and has to be unbound by my friend before I can bind to my air 2s?