Charged it at 7:55pm. Went to sleep with the watch woke up around 80%. It's 2pm and it's at 22%. I haven't used the watch other than wear it to keep time. Its just doing the regular things like heart beat and tracking steps. Haven't used it for work out or any of the other stuff. Battery health is at 99%. Just got this last week. Is this normal use? Thought it was quoted 36 hours battery life under regular use.