RE: single battery possible?
I tried using a 5 cell 2000 NiMh pack with a single lead and ran into what turned out to be a "brown out" condition with full elevator or aileron input. There were no other issues (on mine). I added a second power lead and switch to the same battery and was able to get a couple of short flights out of it prior to running into that same brown out issue. Added a second battery and problem was gone.
OMP 67" fusion/DLE 20/Aurora 9/5 digital high torque servos
FWIW