update:

I have flown the shuttle around 5 to 7 flights. The longest was 6 1/2 minutes and to be honest, that is quite awhile for a single flight. The surprise is that the battery draw has been much less than I thought it would be. When I started the project I planned on 12 to 15 minute flights and I bought 8 tp2100's thinking that I would use them all at one time. Even when I flew for just under 7 minutes the total draw was 2000mah out of 6000 available. (I was only running 6 batteries at the time.) That means I could fly for 15 minutes with some room to spare using 6 batteries. Since I really don't plan on flying 15 minutes at a time, I decided to remove 2 batteries to save weight and now I have two full flight packs of 4 batteries each. I should be able to get a comfortable 8 minutes of flight time out of each set of 4 batteries with room to spare. The upshot of the whole thing is that if anyone wants to convert their 30-size nitro you don't have to buy as many batteries, which will keep the weight and initial costs down.

EDIT: I need to retract that last statement about using 4 batteries instead of 6. The extra margin of available battery power is worth the weight of the two additional batterys, at least that is my opinion after trying 4 batteries for a couple of flights...