SebM
If you use that NiMH 2700 mah 4.8 v battery pack in your piper cub, how many times are you planning on flying it? about 100?

Your transmitter batteries will be dead before that receiver battery will.
I don't have any Piper Cub. I have a H9 Solo Sports Trainer, a Neptune Seaplane and a GP Super Sportster 40. I have only one batterie pack so I just decided to get a second complete kit ( motor, Rx, batt, servos ) to have at least two planes ready to fly anytime. I don't know yet in wich of theses plane I will install the 2700mah batt. My others pack is a Nicd 1100mah and I can easely get 6 flight. However I fly now in the winter and this drain the rx batterie much faster so a bigger pack is more then welcome. My Tx are kept warm when flying so it doesn't seem to be affected by the cold and the batterie last a very long time.
Séb