On my second full day with the Watch, mine is at 15% with roughly 4 hours of use and 7 hours of standby. This was with the screen on full brightness and all features/notifications turned on. I wouldn't be surprised if it reached 4.5-5 hours before dying; this would put it in-line with pre-iPhone 5 iPhones which is pretty impressive considering its size. Here are some tips I've compiled from reading the forum and through my own testing/common sense: Disable "hey Siri" for marked improvements. This feature barely works for me but is useful when it does . Not a huge loss. The microphone not constantly listening while the Watch is on should make a difference. Disable notifications from apps you don't care about it, even if they barely send them. Disable the heart rate monitor caloric readings for workouts. The difference between using the heart rate monitor and not using it for caloric readings is negligible. While I've yet to test these, I believe they could push the Watch to get over 5+ hours of usage which should be plenty. Any more usage throughout the day and you may have a bigger problem with addiction . Update: Also, disabling always-on location service apps on your iPhone could help. As well as the ten-minute heart rate readings. Seems pointless anyway: take measurements when needed.