Has anybody attached an additional battery to the P3? For extended fly time, I think its necessary to attach another (dji) battery(ies) considering: a) The way to connect both batteries (including where and how to drill...), b) To include a resistor to let different batteries to equate voltages adequately, c) the lightest attaching method, d) Not (shade) interfere the communications electronics, e) how many additional pounds can carry the aircraft. f) not affect another sensible systems (cooling? etc). I want to do it but need your experience. Thank you!