Platform Power & Battery Life

The new Nexus 7 moves to a slightly smaller battery compared to its predecessor (15Wh vs. 16Wh). The result however is anything but a reduction in battery life. ASUS and Google worked hard to reduce platform power consumption as much as possible. I instrumented both Nexus 7s and measured total platform power, excluding display, to look at the impact of the silicon platform (SoC, PMIC, DRAM, eMMC, WiFi, etc...). The results are beyond impressive:

Idle power is cut in half compared to last year's model. This is by far the most important improvement as most mobile usage models tend to have long periods of idle time. We'll see these power gains reflected in our web browsing test which does have significant periods of simulated reading time between web page loads. The power reduction while running Kraken grows to just over 20%, and even while running Geekbench 3 we see a 16% drop with the new Nexus 7. Only our offscreen 3D test manages to draw more power on the new Nexus 7 than the old one, and that isn't taking into account the nearly 5x increase in performance on the new Nexus. In fact, as impressive as these numbers are - they are even more impressive when you take into account performance. To make a long story short, don't worry about the ~7% decrease in battery capacity as there are enough improvements in platform power and performance (and thus perf per watt) to more than make up for the smaller battery.

We'll start out with our WiFi web browsing test. Like all of our battery life benchmarks we run this test with all devices calibrated to 200 nits and connected to 5GHz 802.11 WiFi (if supported). The test itself cycles through a bunch of desktop websites at a very aggressive frequency. Our test ensures that both the CPU cores and wireless stack can reach their deep sleep states during simulated reading periods. The test continues until the battery is depleted.

Web Browsing Battery Life (WiFi)

The new Nexus 7 does better here than any other small tablet we've ever tested. Remember that 50% decrease in idle platform power? That's exactly why we're seeing a 35% improvement in battery life compared to the original Nexus 7.

Our video playback test involves looping the playback of a 4Mbps 720p High Profile H.264 transcode of the last Harry Potter Blu-ray. All displays are calibrated to 200 nits.

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

Video decode blocks are fairly well optimized to begin with, so there's not a ton of room for improvement here compared to last year's Nexus 7. Despite the ~7% shrink in battery capacity, the new model manages a 10% increase in battery life though. We also have the first small Android tablet capable of beating the iPad mini in a video playback test here - job well done ASUS/Google.

Our final test involves looping the Egypt HD benchmark until the battery is completely drained. Frame rates are capped to 30 fps to somewhat simulate actual gameplay and not penalize faster GPUs.

3D Battery Life - GLBenchmark 2.5.1

The new Nexus 7 manages to deliver slightly better battery life here despite driving higher frame rates and more pixels. Overall performance here isn't anything super impressive, the only average showing from the Nexus 7.

Google ships the Nexus 7 with an ASUS branded 7W charger, identical to the one you'd find in the box of a MeMO Pad HD7. Given identical chargers and battery capacities, there's no surprise the new Nexus 7 takes the same amount of time to charge as the MeMO Pad HD7 (~3.5 hours).

Charge Time in Hours

The new Nexus 7 also supports wireless charging by implementing the Qi standard. Charge time is a bit slower wirelessly as Qi can only charge at up to 5W. Brian tested Qi functionality in his mini review of the Nexus 7 and didn't have any issues.

Introduction & Display CPU & GPU Performance
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  • jl0329 - Wednesday, October 9, 2013 - link

    Your idiocy made my laugh out loud. You are truly clueless, aren't you?
  • bznotins - Thursday, August 22, 2013 - link

    Is this new version polarized? The 2012 Nexus 7 was on the horizontal axis, precluding from me using it in that orientation as a nav device with my (also polarized) sunglasses on. Looks like a great tablet though.
  • OzedStarfish - Thursday, August 22, 2013 - link

    Yes it is, for my unit it is almost entirely blocked when in landscape unfortunately.
  • amdwilliam1985 - Thursday, August 22, 2013 - link

    Good read, this is one of the very few article that actually praises on the new Nexus 7's battery life :)
  • max1001 - Thursday, August 22, 2013 - link

    I was expecting Gold since the review was all praises. lol.
  • ikjadoon - Thursday, August 22, 2013 - link

    If Anandtech compared this to all other 7" Android tablets, it'd be a gold. But, he might be taking the bigger picture: for myself, 7" is just too small, as well.

    It's portable, though, and for some people, that's more important.
  • Impulses - Friday, August 23, 2013 - link

    I'd prefer 8.9"... But until there's a Nexus 8 I'd rather deal with the size than any of the shortcomings on other current tablets.
  • max1001 - Friday, August 23, 2013 - link

    I think it's better to have both. I have a 7" and a 9". Nexus 7 easily fit in my coat inner pocket and I can bring it with me everywhere. It's also a lot easier to handle on the subway. I can grip it by the side with 1 hand and not worry about dropping it. I user the 9" to watch Netflix and web browse when I am at home.
  • mmarafie - Thursday, August 22, 2013 - link

    I remember the old days when anandtech was the best tech site for reading awesome, detailed, and unbiased reviews. It seems those days are long gone, the more I read the reviews here (especially by Anand) the more I realize the site has become basically an advertising and marketing place for Apple. There are so many tell-tale signs in this review and others where its quite obvious..
  • DukeN - Thursday, August 22, 2013 - link


    I automatically ignore Apple/iOS mentions and figure out my own comparisons to the rest.

    Anand, perhaps this can be a feature for you.

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