RE: Spektrum DX-7
Goose!!!!! GLAD to see your name popup....hope things are well. What I'm using is a modularized-9303. The "full design" 9303 likely won't see daylight till July/August or so. Sorry to confirm that you have learned more about battery impedance. Bummer. But good info....
My 9303 works just dandy, used all existing AR 7000's from the DX 7 days, nearly all settings transferred with no change.
Try to stay cool, if that's possible. God speed.