I have bought a X450 frame:
(http://www.goodluckbuy.com/index.php?target=products&product_id=78864) and an APM 2 controller
and I am a little stumped as to what to choose in regards to power system for my quad.
I am looking to get as long a flight time as possible (goes without saying really) and carry a GoPro and some FPV kit.
What would you guys go for?