Hi Gary and Kevin
My 2 cents on transmitter batteries.
I have a Futaba 7C transmitter and I got tired of charging the stock NiMh batteries for hours at a time. I decided to go with a lipo and bought a 3s 2500 mah 3C Transmitter battery from Heads Up RC.
The downside is Futaba apparently limits voltage to 12v or less. So I charge to storage level of 11.4 volts and allow the battery to go down to 11.0 v. I have not kept track of useage but I know I am getting a lot more flying time compared to the old battery.
Another downside, do not forget to turn the tx off.
That is how I extended my tx time and I can always keep the old NiMh battery arround as a back-up.