The Tech Report writes convertible ultrabooks based on Intel's Haswell processor promise to deliver a battery life of up to 10 hours in tablet mode:
One of the downsides of today's Ivy Bridge-powered convertible tablets is their mediocre battery life. For example, the Samsung ATIV Smart PC Pro 700T we reviewed last month ran out of juice after just 6.4 hours in our web-browsing test—and the screen went dark after just 5.3 hours of video playback.
Happily, Intel's next-gen Haswell processors should improve those figures dramatically. The folks at Engadget got to play around with a Haswell convertible at an Intel event in London, and they say the machine is supposed to run for 10 hours in tablet mode. Connecting the tablet portion to the keyboard dock, which contains additional battery cells, is supposed to lengthen battery life to an impressive 13 hours.