Hi,
I am always switching off my Fenix at night, my tought is that if I can prevent my battery to drain during 7 hours, its life will be improved. Are you letting your watch always on or swithcing it off every day ?
It should have been great to have a "save mode" like on Suunto Ambit 2 entering in a save mode when not moved during 30 minutes, it could improve battery life by limiting draining.