Hey guys i think i figured out a simple equation to accurately calculate the length of flight times based on the mah (milli-amp-hour), and the amperage draw from all your motors combined. Here's a couple units so you can understand better. 1 amp-hour will supply a continuous current of 1 amp for 1 hour 1 amp = 1000 mah Equation: (XAmps·1000)∕60 This equation calculates how many mah's consumed per minute based on your overall amperage draw from your motors. So you can then take the amount of mah's in your battery pack and divide that by your result from the equation. Which results in the amount of minutes you will have. I base my amperage draw off of 65% power continuously. You can find the amperage draw from the website of the motor company you bought from, (most of them). Example: One of my motors draws 9 amps continuously at 65% power. I have four motors so 9 times 4 is 36. So 36 total amps being drawn from the battery. Equation: (36 x 1000)/60 = 600 mah's consumed per minute. I have a 9000 mah battery. So 9000/600 = 15 minutes of 65% continuous power usage.