Batteries: Gearing up for spring, bigger motors.

Flying 8mm (8520 or 816) motors with 240mah / 45C batts seems sketchy, and NFE advises a 2 min timer. This is fairly close to the QX90 spec so I will try using batts in the 600mah range there. 
I am very curious about using the QX90 as a way to ease into 2s... I want more power to carve around the skies.