I've got a friend who upgraded his RC antenna with ease to the fpvcustoms.com upgrade along with the 3000mw booster battery. He Just logged a flight at over 32,000 ft. Even though He was way out there , He still had full signal. Hes now limited by his battery flight times though. His battery ran out of juice and He got it back as it was emerg landing at 6%. Here's my questions: 1. Is there an extended battery out there aside from the stock units that can be purchased that don't require any mods? 2. As far as modified battery systems or kits, which ones are the ones that will get him the longest flight times?