Battery Life

Obviously, battery life is one of the most important aspects of any smartphone, tablet, or other mobile device shipping today. The main point of interest for a lot of people seems to be battery life as even though we’re approaching what might be considered a full day of use a lot of people seem to need quite a bit more as battery life demands can vary dramatically from day to day. If you sit in an office for much of your day with the phone next to a charger then battery life demands are going to be relatively light but if you have to deal with a 12 hour flight with a 2 hour wait for a transfer before another 4 hour flight then you’re probably going to find that most devices are not going to have the ability to get you through a full “day” if your day of use involves 9 hours of usage between movies, games, web browsing, and other data synchronization tasks. This is obviously an extreme case but if you’ve ever done a trans-pacific flight this isn’t that far-fetched if you can’t fall asleep for at least 10 hours of the ~16 hour flight.

In order to try and test this properly then we turn to our 2016 suite of benchmarks which allow for proper characterization of battery life in fairly realistic workloads. In order to make for useful relative comparisons we disable all background tasks and set the display for all devices to 200 nits on a blank white screen for all tests. In the case of the Galaxy Note7 due to its similarity to the Galaxy S7 edge we’ve elected to run a compressed version of our suite although if time permits we’ll be adding additional results and commentary.

Web Browsing Battery Life 2016 (WiFi)

With that said we can start with the WiFi test which shows about an 8% drop for the Note7 relative to the Galaxy S7 edge. This might be surprising to some but given that the display area of the Note7 is 7% larger and the battery is about 3% smaller it’s not all that surprising as I wouldn’t be surprised if literally everything but display has identical power consumption on the Galaxy Note7.

Web Browsing Battery Life 2016 (LTE)

While the WiFi test result is pretty much in line with expectation the LTE test result is visibly different and somewhat surprising to see. It’s tempting to explain the relative difference change away as a function of Verizon and T-Mobile LTE differences but reception was fairly comparable across both test units and both were tested on LTE. Given that the Note7 has 4x4 MIMO for cellular connectivity I suspect that there are some RF front-end changes that distinguish the Note7 from the S7 edge but the RF front-end is only visible to the modem rather than the overall system so unless the modem itself can be accessed I suspect the most viable method of figuring out the changes here will be a device teardown which isn’t in the scope of this review.

PCMark - Work Battery Life

The next point of interest is going to be PCMark which shows how close the Galaxy S7 edge and Note7 are in WiFi and CPU bound tasks as they last basically an identical amount of time and have fairly comparable performance if you get both on the same version of software. Due to time constraints I would refer back to the Galaxy S7 Part 2 Review if you are interested in seeing what heavy workload battery life is like, but overall the Galaxy Note7 keeps fairly good battery life even if it isn't as great as the Galaxy S7 edge.

Charge Time

Of course, while battery life is critical we need to also talk about the other side of the equation which is how quickly it can charge. After all, if you’re stuck in an airport waiting for your connection and burn off most of your battery in the process, it’s going to be fairly painful conserving battery until you get to your destination because your phone can’t charge quickly enough to compensate for additional usage. In order to test something like this, we rely on measurements from the wall and waiting until the power draw from the wall reaches a specified level that indicates full charge has been reached. In the case of the Galaxy Note7, the charger uses QC 2.0 or Samsung’s adaptive fast charge technology depending upon the AC adapter you’re using, and internally the battery charger IC is a TI BQ25898S which contains a buck converter that can take a 9V or 12V input and step it down to the appropriate voltage for the battery with supports for current up to four amps at roughly 90% efficiency.

Charge Time

Looking at the overall charge time the Galaxy Note7 performs respectably as it reaches full charge in under two hours and takes basically as much time as the Galaxy S7 edge, which is probably not a surprise given their similar battery capacities. For the most part I think we’ve hit an upper bound here as far as charge time goes. The real challenge now is to focus on reducing the heat output and impact to battery longevity that these fast charging solutions have similar to OnePlus’ Dash Charge and Qnovo’s Adaptive Charging technologies.

Display System Performance
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  • thunderwave_2 - Thursday, August 18, 2016 - link

    Look at the S7 Exynos stock browser results. Yes, the iPhone 6s still outperforms it, but it isn't exactly "wiping the floor" with it.

    Also, consider that although the onscreen benchmarks seem to be in its favour, the S7 is rendering almost 4 times the pixels. While the Mali T880/Adreno 530 is ahead though, the iPhone 6s does admittedly have superior sustained performance.

    iOS runs less background processes and is less resource intensive than Android, leading to the great battery figures.
    Reply
  • trparky - Saturday, August 20, 2016 - link

    Which tells me that Samsung didn't equip the device with a strong enough GPU to push the amount of pixels and sustain high frame rates. If you ask me, there's no reason why that device should have such a high pixel count. Once you go past a certain point it becomes nothing but bragging rights.

    As for iOS running less background processes, that's a good thing. Yeah, Android is pretty bloated under the hood. And then you throw Samsung's garbage on top and you make it even worse. Android's not nearly as optimized as iOS is.
    Reply
  • slyronit - Tuesday, August 23, 2016 - link

    The device has a high pixel count because it uses a Pentile display, so the effective resolution is always less than advertised. A Pentile 1080p on such a big screen would look like crap. Reply
  • lilmoe - Tuesday, August 16, 2016 - link

    It was surpassed in performance and efficiency a long time ago, by the Exynos 7420... The 8890 widened the gap further.

    I know you guys want to believe that Apple's chips are the best. I feel your pain. But it's not, no matter how many "reviewers" preach browser benchmarks. Geekbench is by no means a legit benchmark. lol.

    Even on the GPU side, the PowerVR has long been surpassed.

    Stop blaming Google's shortcomings on Samsung, Qualcom and others. Google's _services_ are great, but their software and optimization level is absolute brown stuff. Samsung, LG and everyone else has to literally fix Android before releasing a phone/update...
    Reply
  • CloudWiz - Tuesday, August 16, 2016 - link

    Performance...only in multi-threaded benchmarks. Twister absolutely destroys A57 in any single-threaded benchmark and since for the vast majority of use cases (i.e. web browsing) the OS only uses one core, the overall user experience is so much better with the A9. Mongoose is catching up but still not at Twister's level.

    As for efficiency, the modem on the S6 makes it last a ridiculously short amount of time on LTE and even on Wifi the 6s lasts half an hour longer with a battery two-thirds the size of the S6. The 6s Plus lasts a full 2 hours longer with a similar size battery.

    The GT7600 was only beaten in GFXBench this year by the Adreno 530 and surpasses both Adreno 530 and the T880MP12 in Basemark (it also has equal performance to the T880 in Manhattan). You make it sound like the GT7600 is multiple generations behind while it is not. It absolutely crushes the Adreno 430 and the T760MP8 in the Exynos 7420. The GX6450 in the A8 was underpowered but the GT7600 is not.

    I do hope that at some point Apple adds two Cortex-A53s to help with low power tasks, but given that their dual-core design already achieves insanely good performance (with the A10 seeking to equal the performance of A9X in a mobile device), they might not even need to.
    Reply
  • lilmoe - Tuesday, August 16, 2016 - link

    "and since for the vast majority of use cases (i.e. web browsing) the OS only uses one core"

    False. On Android, the vast majority of applications take full advantage of 4 or more cores.

    "As for efficiency, the modem on the S6 makes it last a ridiculously short amount of time on LTE and even on Wifi the 6s lasts half an hour longer with a battery two-thirds the size of the S6. The 6s Plus lasts a full 2 hours longer with a similar size battery."

    Also, false. As proven by personal experience, with good reception, the modem on the modern Exynos chips can be more efficient than WiFi. What you're seeing in the charts, my friend, is that Safair (or any browser for the matter), is more efficient that Chrome (shocker). What you're also seeing is that, 720p and 1080p are more battery friendly than 1440p (another shocker). It's amazing that the GS6/GS7 can keep up with that much overhead and more pixels to push.
    Reply
  • osxandwindows - Wednesday, August 17, 2016 - link

    Not really, those cores are waisted cores.
    The scheduler sucks, therefore making android inefficient overall when it comes to the use of multiple cores.
    Reply
  • thunderwave_2 - Thursday, August 18, 2016 - link

    http://www.anandtech.com/show/9518/the-mobile-cpu-...

    This piece shows that, on the S6 at least, not all of those cores go to waste.
    Reply
  • osxandwindows - Thursday, August 18, 2016 - link

    Nope, you don't get it. Reply
  • osxandwindows - Thursday, August 18, 2016 - link

    I'm not saying it can't use them, I'm saying it can't use them an a way that doesn't affect performance or battery life. Reply

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