Since installing watchOS2 last week, I have had several days where my battery on my 38mm reaches less than 20% by bedtime, which I haven't been seeing since I've had the watch in May. Usually it's at about 40%. Today for example. Up at 8am, it's now 11pm, I'm on 14%. Checked my usage, and it's saying 6 hours 4 mins with 15 hours 11 minutes standby. What the heck counts as usage?? I swear all I have done today is receive notifications and check the time!