3 minutes to over 2 hours...
EDFs will pull down a pack fast. Motor-gliders can float around a long time if you catch a thermal.
I have a power system that will go 17 min at full throttle on 1800 mah 3S and I have one that will pull 12S 5000 mah down to LVC in under 2 min...
Several planes, several chargers and many batteries = a lot of flying.
It can take a while to build up the stuff for that.