Hi
tailstrike4,
I am saying it may cause the receiver to think it should bind. I am erring on the side of safety since I do not know exactly how the Spektrum receivers are built inside.
We recommend using both power leads into the receiver. You should plug one into throttle and the other into the last AUX on the receiver for JR or Spectrum (first and last servo ports) . On Futaba you would plug into Aileron and the last Aux(again, first and last servo ports). If you have less channels than the PowerExpander on your receiver you should leave on or more of the single lead connections unconnected. This provides redundant power to the receiver. You will always have redundant power to the system if you are using both battery inputs to the PowerExpander.