Windows RT devices to sport up to 17 days of connected standby, some are thinner than the new iPad

Windows RT tablets and notebooks will have a feature similar to Apple's PowerNap, where they maintain their connected state while powering down most other battery-drawing functions. Thus the active standby of an Windows RT device has shown in internal tests to be between 13.3 to the whopping 17 days of staying connected on a single charge, while HD video playback has continued from 8 hours to 13 hours, depending on the tested device.

Microsoft spilled some more beans what kind of devices can we expect at launch with Windows RT - they will be made by Asus, Samsung, Dell and Lenovo, and will have 10.1 to 11.6" screens in a tablet and convertible notebook form factors. The lightest ones seem to be just 520g, whereas thickness hits 8.35mm, which means that we will have a Win RT slate that will be thinner than the new iPad.

source: Microsoft