That's what I'm thinking also. I've been actively testing WatchOS2 since the second beta and had severe battery issues in beta 3-5. My watch would die by 2:00pm

That's what I'm thinking also. I've been actively testing WatchOS2 since the second beta and had severe battery issues in beta 3-5. My watch would die by 2:00pm every day. I finally uninstalled all third party apps and that fixed things. I tried to find the culprit by reinstalling the apps one at a time but was unable to find the little vampire.