I love the watch but the battery doesn't last all day. I put the watch on around 6:30 am and by 7 pm, it dies. Forget wearing it over night. I wore it over night a couple of nights (because I wanted to use the sleep monitoring). The watch was dead by noon. Basically, you have to choose to either wear it over night or during the day. 14 hours seems to be the max battery lufe.