Originally posted by PUNISHER
I'v raced (3 quilifers and a 15min main) all day long with one charge on my 800mah RX pack.
Yes, I've noticed that on my 705 with 2 Futaba S9451 digital servos, I use up slightly less than 100 mAH per 5 minute heat. I think in your case, you end up using about 600 mAH which a 750 or 800 mAH pack should do it.
I've read that hardcore racers who use 150 mAH packs that are very light just for the 5 minute heats...