Here is a picture of my old DX-7 flight pack installation in a my 40% Carden Extra 260 back in 2007, and the 9 ea. JR 8611 servos were powered with two each Fromeco 2200 ma lion packs.
If you note in the picture there is a custom manufactured switch with a two battery input side and a three lead output side on the same circuit, the switch supplied power to two each Specktrum receivers and the DA ignition module all from the same switch and again same circuit, I performed this as a test bed study on RF noise while using 2.4. Anyway in over 500 + flights with this setup there was never a singe issue of a brownout power fade or signal RF noise interruption. I am happy to tell you all that this airplane is still around and flying today guys, I still have my DX-7 but I fly now with my Stealth.
Bob