Steve, I just built a Concept 30 for a guy. The Transmitter was Futaba's 6 channel heli radio. Unfortunately, I don't remember the nomenclature. I did not look at it carefully, but when I opened the battery compartment, there was not an obvious place to unplug the battery. I could see the lead going down behind the plate behind the battery and going all the way across to the other side of the tx.

Maybe there was some simple way to unplug it, but it wasn't immediately obvious so I just put it back together. It looked like I would have to unscrew the back or something to get at the battery plug.

again, I could be wrong about it, but because it was a customer's radio, I didn't want to mess around with it.

BTW - I use Sirius chargers. I have two - one on a deep cycle "lil' Rascal" battery (30 amps maybe?) and the other on a 12v AC adapter.