Battery Life: The Downside

Despite having an integrated 42 Wh battery (similar in size to the 3rd and 4th gen iPads with Retina Display), battery life is a real sore spot for Surface Pro. Haswell is really designed to drive platform power down to very low levels, which should help close the gap between ARM/Atom based tablets and Core based tablets. Unfortunately, Haswell for tablets won’t hit until the third quarter of this year, which forced Microsoft to use Ivy Bridge.

In our tablet benchmarks, I never saw Surface Pro break the 6 hour mark on a single charge. In most cases I’d expect to see 5 - 6 hours out of Surface Pro in light, tablet usage. Video playback was especially disappointing as Surface Pro managed to use more power here than during our web browsing battery life test. I suspect this might have to do with the relative power efficiency of Ivy Bridge's video decoder. It'll be interesting to see how Haswell does in this department.

Web Browsing Battery Life

Video Playback - H.264 720p High Profile (4Mbps)

I also put Surface Pro through some of our new notebook battery life tests for 2013, and here it didn’t fare too bad. I only have Acer’s 13-inch S7 to compare to but Microsoft managed 3.85 hours in our medium workload compared to sub-3 hours for the larger Ultrabook:

Windows 8 Notebook Battery Tests
Battery Test Acer Aspire S7 (13-inch) Microsoft Surface Pro
AnandTech 2013 Light 4.00 hours 5.2 hours
AnandTech 2013 Medium 2.88 hours 3.85 hours

This is easily the biggest disappointment with Surface Pro. You just won’t get the all day battery life you do with an ARM based tablet out of this design. I expect Microsoft will have a solution to this problem with Haswell, but not until the end of the year.


Surface Pro retains the same large, magnetic power connector as Surface RT. In fact, Surface RT’s power adapter will still charge Surface Pro. The Pro model does however come with its own 48W adapter. It’s a nice looking, but large and still fairly traditional two piece power supply (brick + detachable wall cable). There’s no sophisticated cable management other than a tiny hook to help keep the device end of the cable together. One neat feature is the power adapter does feature an integrated USB port for charging your smartphone.

Under max charging load the power supply will draw around 27W at the wall. Microsoft included a 48W unit in order to be able to charge and power the device without slowing down charge time. It took me 2.692 hours to charge Surface Pro from completely empty to 100% with no additional power draw at the wall. The quick charge time is pretty nice and about the only reprieve here when talking about Surface Pro's battery.

I did notice something odd with the first power supply Microsoft sent me. When charging through my power meter, I picked up some interference in the capacitive touch screen itself resulting in around 10% of my taps not being recognized. Microsoft supplied another power supply that seemed to resolve the issue.

Display: Awesome if Calibrated Final Words
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  • bobjones32 - Tuesday, February 5, 2013 - link

    Since the Surface Pro is basically half-tablet and half-laptop, wouldn't it make sense to include a graph that compared it to other laptops too? Based on the numbers here, it seems like the Surface Pro would come out well ahead of the Macbook Air 11", for which its specs and price seems to most directly compare to.
  • karasaj - Tuesday, February 5, 2013 - link

    I second this. I would like to see it compared with laptops as well - a lot of the other tests included laptop comparisons as well.
  • Anand Lal Shimpi - Wednesday, February 6, 2013 - link

    The problem is our Windows 8 battery life suite only has one datapoint at this point: Acer's 13-inch S7 ultrabook, which I did include in a table below the graphs on the battery life page. I will try to run the 11-inch MBA this week/weekend in the new suite to get a good reference point though.

    Take care,
  • remain_insane - Wednesday, February 6, 2013 - link

    Awesome! It will be nice to see that included in here so we can see that comparison and have the PRO be put into against another similarly priced competitor.

  • bobjones32 - Wednesday, February 6, 2013 - link

    Cool. I was specifically looking at your 11" Macbook Air review from last year where it got around 4 hours of battery, vs. the numbers here.

    Anyway, great review! Thanks.
  • JanieMartin - Thursday, February 7, 2013 - link

    Love my job, since I've been bringing in $5600… I sit at home, music playing while I work in front of my new iMac that I got now that I'm making it online.(Click Home information)
  • phillyry - Friday, February 15, 2013 - link

    ^That's SPAM right above me ^
  • apollomission19 - Tuesday, May 7, 2013 - link

    Dont click the LINK in previous comments... pure SPAM! This should have a "report" button or something to report this piece of *hit.
  • TwistByrn - Wednesday, February 6, 2013 - link

    I would also like them to specify that the RT and the PROs 128GB of storage is partially used up by the operating system were as the iPads storage is not used by the OS.
  • ATGS-Jason - Friday, February 8, 2013 - link

    Actually, the iPad's storage IS used by the OS as well, they're not separate. More importantly, iOS is nowhere near on the same level of capability as Windows 8 or RT. With regards to the Pro, the proper comparison is to the Macbook Air, which uses almost exactly the same amount of the integrated SSD as Windows 8 Pro does (within 2GB), except that the Win8 Pro total on Surface Pro includes a complete recovery partition that can be offloaded to a USB drive. When you do that, Windows 8 on Surface Pro actually takes up about 7GB *less* than the Mac OSX stock installation on an Air.

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