RE: using two battery packs
JeffK, The added weight of a second battery pack on an airplane with a 72 inch wingspan is insignificant ..... don't worry about it. However, just simply plugging a second pack into any open port on the receiver is not the recommended method. If one of the packs is failing due to a bad cell or short curcuit .... it will probably drain the other pack down with it. I use the Jomar-EMS Ultimate battery backer in most airplanes. Both packs are plugged into it and it has electronics in it to prevent the draining of the second pack I described above. It is not expensive .... and provides the true power redundency you want. Bob