Afro 20A OPTO ESC High Voltage 3-8s (SimonK Firmware)
The secret to long flight times is high voltage. These new Afro speed controllers (ESCs) support just that; while conventional ESCs run at up to 6S (25v), the HV Afro's are compatible with up to 8S (32V). Matched with some low KV motors this makes for a very efficient setup, with flight times pushing over the hour mark possible! Best still it needn't be expensive, while 8S LiPo batteries are expensive and hard to come by, you can just run two 4S batteries in series to the same effect. That way you don't even need a fancy high cell charger.