In a race 2-3 minutes reliable. 4-5 goofing around casually, MAYBE 7 if you are not doing anything fancy. It also depends on the size of your quad and what batteries you use. Race batteries are usually smaller between 1300 and 1800 mah which is why such a short time. 2200mah can give between 7 and 12 minutes if you aren't racing and flying at max rpms but they are heavier and usually not used for a race situation.
If you are new and have not bought batteries before I suggest two things for racing.. 1st get a decent programmable charger. Them cheap "Trickle" chargers will puff your batteries and could possibly cause a fire. 2nd for a quad copter you want batteries with a higher C rating. 45c or better for racing and freestyle 35c or better for just learning and regular practice. I started with 20c batteries and it was a short time before I was pushing them to their limits
Hello Alie, Everyone plan to diy a quadcopter want to make this question clear, do you want to build one? How long can a quadcopter fly? But there’s no one rule to give a definite answer to the question. I will be showing you how long time can achieve main work demand of common quacopter in order to know approximate ranges for quadcopter flight time.
Taking aerial videos or photograph 10-25 Mins
FPV 2-5 Mins
Mini drone 1-2 Mins
agriculture 15-30 Mins
Would you tell me which type quadcopter do you want to buy or buld?