I will probably get corrected for this, but I use 6v NIMH batteries for the receivers in all of my planes. I use the JR trickle chargers that plug into the wall since I have a JR radio and use JR or universal connectors and I just keep my planes plugged in and charging at all times when I am not at the field. When I'm ready to fly I simply unplug the plane from the charger and go fly. I check the batteries under load before every flight and I do not fly on a battery that is not in the "green" on my volt meter. I've never had a problem with a battery discharging too fast or while I'm in the air and the planes are always charged and ready. When I get back home I plug the battery back into the charger and place it on the storage rack. Now I would not follow this procedure with Lipos or Nicads, but this has worked well for me with NIMH batteries.
Indy Park Flyer