RE: recommended battery for 7 servos
Yes, it is a standard 4.8volt pack from Futaba, 600maH capacity, the one that came with my transmitter when I purchased it. Immediately after charging using the standard Futaba wall charger (4.8v charger), my pack reads about 5.7 volts. I get the exact same readings on another Futaba receiver battery in another plane--same battery: 4.8 volts; 600maH capacity. At one point I put a post in the battery forum about this because I was surprised that it charged up so high. I figured a 4.8volt pack would charge to 4.8 volts. Someone replied showing some type of charge diagram from Sanyo who makes the batteries and each cell does charge up higher than 1.2 volts and 5.7 volts for the entire pack was not uncommon.
-Ed