I've had mine since christmas, and even at that time the battery life wasn't that great, but that changed when we hit 2.1 (I think...).
Maybe I'd have to try and do a factory reset after re-installing 2.2.
What I find strange is that I haven't changed anything, same watchface, same apps.... just a new PebbleOS...
On the same night I had installed it, I was at 30%. Next morning (8h later) the watch was completely dead. Unless I use my Pebble while sleepwalking, I don't know what happened there!
I have quiet hours setup too.