My SW2 lasts for several days. Its batt life is just amazing especially for a bit of a slacker like me, I don't wanna charge regularly.
My Pebble lasts for 3-4 days. Awesome.
My smartwatch: Samsung Galaxy GearIt should last for 24 hours but mine only does for like 18, so charging it everyday is a regular thing. Whew!
My Strata lasts for 4-5 days.