From what I have heard the spectrum RX draws more power than a normal fm rx. If you are going to use all top of the line digital servos as well like 8711's, 5955's, or 9156's? I would recommend using a 4 cell lion like a Fromeco 5200 with heavier guage wiring and fromeco reg with upgraded wiring as well, and HD switch. This setup should be more than enough in high draw applications.