Thanks for the link, AT. I'm not sure why the "diode" in the circuit would keep the batter charger from recognizing peek, unless the charge leads are on the board side of the diode and charging would be through the diode.

The diode in a Futaba is there simply to prevent damage to the board if a JR or Spectrum charger was attached. They cause a mess in a Futaba since they have reversed polarity.