ORIGINAL: jetmech05
I was taught by my instructor 3 flight is good, 4 is ok, after that be careful. Now this guy has been in the hobby long enough that I think he taught Orville and Wilbur to fly RC.
Better safe than sorry.
It always helps to first establish what the limits are of your equipment as you are doing, and then periodically check just in case.
With the bigger packs ( albeit at an increased but useful weight penalty ) you can fly all day long.
Usually well over 10 or more 15+ minute flights per plane.