Quote:
Originally Posted by Aeroplayin
Charge your battery
Set your timer for 2 minutes
Go fly normally for the full 2 minutes
Recharge your battery and read the mA that you returned to the battery before you disconnect the battery from the charger  most chargers will display this.
Take the mAh rating of your battery and multiply it by 0.8, so if you have a 3000mAh battery, then 0.8 x 3000 = 2400. This is 80% of capacity because you don't want to completely drain your battery.
Divide the mA you put back and divide 2400 by this number
Take that number and multiply by the 2 minutes to get your projected flight time
So if I flew for 2 minutes and put 800mA back into the 3000mAh battery, then 0.8 times 3000 is 2400, and 2400mAh divided by 800mA is 3.
3 time 2 minutes is a projected flight time of 6 minutes.

Heyy... that's my line!
Also, when you come down, check your voltage. If you have 3.7 volts per cell, that's borderline. Try and adjust your flightime (using 75% capacity instead of 80% mentioned above works best, I've found) so you land with about 3.753.8 volts per cell. This will extend battery life (life as in number of cycles).
Tom K.