How long of a charge using a Futaba 50ma charger....?
A Futaba charger (receiver side) will charge a 5 cell pack at 40 mA and on the transmitter side it will be 80 mA. Transmitter side will charge a 4 cell pack at 105 mA. Do the math from here. If you are charging at less than C/20 the charge acceptance starts to deteriorate significantly and the 140% input rule goes out the window in most cases.