Formula for Run Time

run time in minutes = (Battery Capacity in Ah/Motor Current in A) x 60

For this example:
Battery Capacity is 8000 mAh = 8 Ah
Motor Current = 65A

Therefore:

run time in minutes = (8 Ah/65 A) x 60 = 7.38 minutes

This assumes that you run at full throttle and can drain the battery completely. In practice, before the battery is completely drained, the power will have decreased to the point that the plane will no longer stay in the air.

- Jeff