what size RX batt for a Razzle 3D?
I am using a 4 cell 1650 mah RX pack. This is a NiMh pack and seems to be plenty juice. Keeps in mind, if you use a 5 cell (6 volt) RX pack, the servo's will draw more power from them than if you use a 4 cell (4.8 volt) pack. Therefore, I would go for as least the 1650 mah pack. I have 4 HS77, one 5625, and a standard for throttle.
Good Luck,
EdMan