I usually carry an extra charged lipo receiver pack when heading to the field. I can easily swap in the charged pack if I really want to make more flights. It is a good idea to know the # of flights that I can safely get with a good margin out of a charged pack so that I can make the swap at the right time.

On my e-powered Sequel, I can safely have five flights with the Intermediate sequence in each, with a fully charged 480mah TP Pro pack.