How many flights are you planning on in a day? Standard training at our field is considered to be 6, ten minute flights. You won't get 10 minutes out of a battery pack unless you upgrade, more like 6-8 minutes then you have to land. Then do you want to plunk in another fully charged pack or put the pack on a charger and wait 45 minutes to an hour?!? Now you either need more battery packs or a fast field charger. On glow planes, you refuel and you are ready to go again. [8D]