Battery Life

Microsoft made no sacrifice in battery capacity in pursuit of Surface Pro 3's thin chassis design. The new tablet features an integrated 42Wh battery just like the previous two models. Charging duties are handled by an external 31W charger with a brand new magnetic connector. Microsoft never seemed to get a good MagSafe clone working in the previous models, so Surface Pro 3 abandons the previous design entirely in favor of something a bit more sensible.

The new connector no longer looks like an oversized MagSafe connector, and instead features a thin plastic insert that mates with the charge port on Surface Pro 3. Charge time hasn't changed, you can fully charge the device in around 2.62 hours:

Charge Time

The device-side connector features 40 pins but you only need 12 of them to charge the device. The remaining pins are used for Gigabit Ethernet, USB, DisplayPort (up to 4096 x 2304) and audio. Microsoft seems hell bent on avoiding Thunderbolt at all costs so instead of embracing the standard it has created a custom alternative of its own doing. The benefit to Microsoft's connector is it can obviously deliver more power than Thunderbolt can, the downside is that it can't send PCIe and thus you don't get support for any ultra high bandwidth external storage devices. I still would rather see Microsoft implement Thunderbolt as there's at least an existing ecosystem built around that but here we are three generations into Surface and if we haven't seen it by now I don't think we're ever going to.

The supplied power adapter includes a USB charge port capable of delivering 1A at 5V.

As Surface Pro 3 is designed to be both a laptop and a tablet I've run it through both our Windows laptop battery life tests and our tablet battery life tests.

Laptop Battery Life

As a laptop, Surface Pro 3 delivers comparable battery life to other optimized Haswell ULT designs. I threw in Sony's Vaio Pro 13 into the mix because it has a similar sized battery (37Wh vs. 42Wh) and is one of the most power efficient Windows Ultrabook platforms on the market. Surface Pro 3 manages to deliver similar battery life, which means it's a little less power efficient but the two are within the same range at least.

Compared to Surface Pro 1 and 2, Surface Pro 3 at worst delivers similar battery life and at best increases range on a single charge by up to 20%. We're looking at 3.75 hours - 7.6 hours of notebook usage on a single charge depending on usage.

It's worth noting that there's a substantial advantage in battery life if we look at the 13-inch MacBook Air running OS X. I only mention this because of Microsoft's insistence on comparing Surface Pro 3 to Apple's popular line of notebooks.

Battery Life 2013 - Light

Battery Life 2013 - Medium

Battery Life 2013 - Heavy

Tablet Battery Life

Tablet workloads are going to be far more display power bound than anything else. Here we see 7.58 - 8.03 hours of continuous usage, a slight regression compared to Surface Pro 2. Video playback remains more power hungry than web browsing, which is something I've noted in previous tablet-evaluations of Intel's Core silicon. I don't believe Intel's Core processors are very optimized for video decode power consumption. If anything is going to change with the move to Broadwell and Core M I suspect video decode power may be it.

Video Playback Battery Life (720p, 4Mbps HP H.264)

Web Browsing Battery Life (WiFi)

Thickness, Thermals and Core: Understanding how Surface Pro 3 Got so Thin Display Analysis


View All Comments

  • dupawow - Monday, June 23, 2014 - link

    Great review! Can't wait till i get mine. Reply
  • drmyfore - Monday, June 23, 2014 - link

    Surface Pro 3 / 800g (+295g TypeCover=1095g)
    Macbook Air 11 / 1.08kg
    Macbook Air 13 / 1.35kg

    Surface Pro 3 / 2160*1440
    Macbook Air 11 / 1366*768
    Macbook Air 13 / 1440*900

    Surface Pro 3 / 9.1mm (4.8mm TypeCover=13.9mm)
    Macbook Air 11 / 17mm
    Macbook Air 13 / 17mm

    Surface Pro 3 / 9H
    Macbook Air 11 / 9H
    Macbook Air 13 / 12H

    Why not compare with Air 11?
  • dylan522p - Monday, June 23, 2014 - link

    Because it is luster in terms of screen size and real estate. Reply
  • dylan522p - Monday, June 23, 2014 - link

    Bigger* Reply
  • rodolfcarver - Friday, October 3, 2014 - link

    It sure is an fantastic tablet. For work, I don't see how you could get anything better (but for other things there are, see ). I've had mine for a couple of weeks and couldn't be more pleased. Reply
  • bestllc - Monday, July 8, 2019 - link

    Thanks for Your writing i found them interesting
  • MarcSP - Monday, June 23, 2014 - link

    Then, why compare it with the even bigger MBA13? :-] Reply
  • darwinosx - Tuesday, June 24, 2014 - link

    Bigger? By what? Oh, pretty much nothing. Reply
  • basroil - Tuesday, June 24, 2014 - link

    "Bigger? By what? Oh, pretty much nothing."

    I suggest you pull out a calculator and do the math, that 2" increase is a 40% increase in area!

    With 40% more area you get a hell of a lot more room to dissipate heat and that much larger battery (54W vs 38W). When comparing surface pro's 7.58 hour life to the 13" MBA the difference is only 22% despite a 29% decrease in battery size (both on windows, . Compared to the 11" MBA (about 8.5hours on OSX) the SP3 should be very competitive, and should last substantially longer in heavy use tasks.
  • retrospooty - Tuesday, June 24, 2014 - link

    You are also comparing a laptop to a convertible. Not really in the same category. The SP3 kicks the MBA's ass IMO. Reply

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