http://www.microsoft.com/microsoft-band/en-us/support/hardwa...
http://www.microsoft.com/microsoft-band/en-us/support/hardwa...
A smartphone can go 48 hours if you turn off all the radios too. The 48-hour claim seems mostly meaningless to me.
My Lumia 1520 goes for longer than 48 hours, with all the radios ON.
However, this is better than many of the smart watches to me, why have a large circular face?
Plus the price point of $199 isn't bad at all.
I haven't delved into wearables yet. I mostly have used my iPhone 5s (now 6) for the motion tracking, but it certainly doesn't catch everything (let alone doesn't catch vitals) since I don't carry it everywhere.
My biggest complaint with the Fitbit is the lack of any battery meter on the device itself. Unless you sync frequently, you wouldn't know when your battery is running low.
You can bet that is with everything off. Looks like its going to be a 1 day device with GPS/Heart Rate and moderate usage.