I found a 2 cell 15c 1300mah pack that I think will work great.. The size seems correct.. I love this radio, but I spend a ton of time fine-tuning and flying..The stock pack only gets me threw a morning of flying.. Hitec needs to upgrade the A9 to a Lipoli..
Ps... Love the throttle curve tuning..
, and the expo is fine as long as you add app. 10%-12% more than your last radio.. I ended up going from
75% to 85%