My Fenix 3 has had reasonable battery performance since I got it 7 or 8 months ago - until recently.
Last night, for example, I went to bed and as I always do, turned off the Bluetooth in the watch (since my phone is also off overnight). I noted battery remaining of 55%. When I woke 8 hours later, the watch was off with a 100% flat battery.
It was charged to 100% at noon on 22nd January, so it had gone completely flat in just under a week.
I have used no GPS (a big power drain) and Bluetooth is off at night. WiFi never on. Only step counting, time, ABC functions. No sports other than step counting in that week.
This seems to be a very fast battery drain and it used to last around 14 days. I can surmise that recent firmware updates may have had unintended consequences but also wondered if anyone else had experienced similar?