So I installed the firmware update on my FF2, and lo and behold, the battery performance has improved. Before the update, I would get the red light syndrome on the second day after a full charge (once a day session, just before bedtime). Even though the battery would indicate it was still full, I would get red lights during heating. As others have reported, I could “power through” five or so red lights and get one final session. Since the firmware update, I have noticed that the battery indicator shows a steady decline in power level and that I can go 4 nights between charges.