I charge my A123's in the plane using a basic switch withcharge port. All you have to do is pull the signal wire that goes to the receiver, so that the receiver gets only the red and black leads. Otherwise you'll have 3.3 volts going into the receiver on the signal wire, whichcan damage the receiver.

Here's the link that explains how to make the mod.http://hangtimes.com/a123rxsetup.html. Read the "Basic Combo Solution Switch Mod..." section.

Very simple and convenient.

Joe