If we are talking a 5 inch mini quad with a decent spec and racing parameters and you know what you are doing, I’d say anywhere between 3:00 and 4:30.

If you take it extra easy, cruise and go smooth, might even set a record time, like I did in this video - the longest I have ever flown on a single battery without killing it.

I flew over 8 minutes on a 1500 mAh 4S lipo, and only brought it down to 3.5 volts per cell. That was extreme for me, normally, I take good care of my batteries and fly for about 4:00 - 5:00 minutes per pack, bringing them down as low as 3.6v - 3.6v