Not that I noticed. Mine is on all day. The biggest drain on the battery is the use of the GPS. I used only the primary notifications of text and calls with the heart rate being monitored every 5 minutes and started at a full charge from January 1st to the 15th. On the 15th I was down to 48%. Before that, I had everything going when I got it and I had to recharge in 10 days. Still better than my prior watch which had less and still needed to be charged in 3 days.