I charged it to 100% exactly 22 hours ago and it's been running continuously on battery since then and it's now at 84%. I was very surprised because I definitely thought I'd have to charge it everyday. I turned off heart rate and activity tracking because I don't use those. I disabled 'raise to turn on screen' because it keeps turning on when I don't want it to. I received a lot of notifications today and I used my watch quite a lot to look at time, calendars (schedule), notifications, etc. If you're a casual user like me, definitely don't worry about the battery life.