To get 2 days on one charge, Ive been taking advantage of the power reserve mode. I'll usually put my phone on power reserve from 10am-12pm and 1pm-3pm. During these times, I'm usually in meetings and don't need my phone or notifications. I keep my phone on sleep mode inside my briefcase. If an emergency pops up, my phone will go off after three consecutive calls. Other than that, I don't need my watch during meetings unless to check time. By 11pm on day one, my watch is around 65%. I'll put the watch on power reserve mode and wake up with my watch around 58% which is enough to get me through a second day.