I big factor is wht pinion you're using. I run the 13T in mine and get around 5 minutes. You can probably count on at least 8 with the 12T. Another huge variable is what type of flying are you goin go be doing? I pretty much fly in idle up all the time and am usually doing 3D the whole flight. Hovering requires far less power, so you could run the 11T and get really long flight times. Then switch pinions as your skill improves.