I've only been using my V2 at the house in the evenings due to the HUGE plumes of vapor it produces but, I went
three night on a seasoned set of batts. That's at least 8 or 9 hours. Maybe the resting let them restabilize. And, I pulled them and
threw them in the charger way before they were empty.
From dealing with $400 lipos I've learned not to try and totally exhaust them.
They seem to last longer and produce a steadier voltage for longer periods.
*Just my experience*