To answer this thread's question directly...
I use a 6V 1650 nimh as a receiver pack running 4 3004s. My transmitter timer is set for 13 mins of flight time but usually keep it up for about 15. That being said, I was able to fly 7 tanks worth of fuel before my voltwatch dropped down only one light. That's well over an hour and a half of actual flight time while still keeping the Rx pack in a very safe charge state. Hope this helps you [8D]