I have the same JR 8103 8 channel PCM radio/PCM Reciever, as you, just different JR servos, I use a JR 6cell 6.0v/1800Mah with out any problems. I use it for 11 JR Servos and 1 JR Gyro. On a full charge I fly 2 times, for about 8mins each then I recharge. I usualy get a 7.1v reading after charging after 2 flights its around 6.6v.

This weekend i'm going to try a Sanyo HC 2000mah 4.8V battery on the above setup, just to see if i can feel any difference in flight. But 1 thing I do notice on the ground when i switch from a 4.8v to a 6.0v is that the Servo apprears to be alot quicker in response and pulling more power from it.


hope this helps

Robert