Battery Life

With the iPad Air Apple moved to a 32.4Wh battery, a significant decrease from the 42.5Wh unit in the 3rd and 4th generation iPads. The smaller battery doesn’t come with a change to Apple’s claim of 10 hours of battery life, which implies a reduction in overall platform power. I confirmed a substantial reduction in platform power in my crude measurements earlier in the article. Although it’s possible for the iPad Air to draw substantially more power than the iPad 4, our earlier power data seems to imply that it’s unlikely given the same exact workload. Our battery life tests agree.

We'll start with our 2013 smartphone/tablet web browsing battery life test. As always all displays are calibrated to 200 nits. The workload itself is hidden from OEMs to avoid any intentional gaming, but I've described it at a high level here.

Web Browsing Battery Life (WiFi)

Our web browsing workload came in at exactly 10 hours of continuous usage - an improvement compared to the iPad 4. Battery life on LTE was good as well, consistently delivering just under 10 hours of usage. The fact that both LTE and WiFi tests deliver similar results tells me that we may be bottlenecked by some other component in the system (perhaps display?).

I've been running the same video playback test for a while now, although we're quickly approaching a point where I'll need to move to a higher bitrate 1080p test. Here I'm playing a 4Mbps H.264 High Profile 720p rip I made of the Harry Potter 8 Blu-ray. The full movie plays through and is looped until the battery dies. Once again, the displays are calibrated to 200 nits:

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

Video playback battery life also improves slightly compared to the iPad 4. Apple’s battery life claims aren’t usually based around video playback, so exceeding their 10 hour suggestion here shouldn’t come as a shock. Apple’s video decode power has always been extremely low.

Our final cross-platform battery life test is based on Kishonti's Egypt HD test. Here we have a loop of the Egypt HD benchmark, capped to 30 fps, running on all of the devices with their screens calibrated to 200 nits.

3D Battery Life - GLBenchmark 2.5.1

Our 3D battery life rundown test shows a substantial improvement in battery life over the iPad 4. IMG’s PowerVR G6430, running a moderate workload, can do so more efficiently than any of the previous generation GPUs in Apple’s SoCs. Much like the A7’s CPU cores however, there’s a wider dynamic range of power consumption with the G6430. Running at max performance I would expect to see greater GPU power consumption. The question then becomes what’s more likely? Since the majority of iOS games don’t target the A7 (and instead shoot for lower end hardware), I would expect you to see better battery life even while gaming on the iPad Air vs the iPad 3/4.

Charge Time

The iPad Air comes with the same 12W USB charger and Lightning cable that we first saw with the iPad 4. Having to only charge a 32.5W battery means that charge times are lower compared to the iPad 3 and 4:

Charge Time in Hours

A full charge takes a little over 4 hours to complete. The adapter delivers as much as 12W to the iPad, drawing a maximum of 13.5W at the wall. I still think the sweet spot is somewhere closer to 2.5 hours but that’s another balancing game that must be played between charge time and maintaining battery health. It’s still so much better than the ~6 hours of charge time for the iPad 3 and 5.69 hours for the iPad 4.

WiFi & LTE Connectivity Usability, iOS 7 and the Impact of 64-bit Applications
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  • over9k - Tuesday, October 29, 2013 - link

    Two paragraphs in and this is already better than all the other "reviews" out there. Reply
  • Beautyspin - Tuesday, October 29, 2013 - link

    You should not really call any review by Anandtech of Apple products as reviews. They are homages paid to their shrine. This is a ritual with them.. Reply
  • Drumsticks - Tuesday, October 29, 2013 - link

    I always hear people complaining about bias here and elsewhere for apple products. But what exactly is the reason for that? The majority of the review is seriously objective - you can't argue that apple has some of the best performance in he game right now, and the best display to boot. He only thing rivaling it is probably the higher clocked Z3770, while Qualcomm will probably pass Apple's GPU early next year.

    as far as subjectivity goes, even if you don't like the design, the materials are solid. And it manages to be lighter than every other ten inch tablet on the market (and thinner) withot sacrificing battery life. The only subjective things I could possibly see are maybe the sound quality and the OS itself, of which he criticized a few times. Where does the bias come in?
    Reply
  • Fleeb - Tuesday, October 29, 2013 - link

    "and the best display to boot"

    We have yet to wait for the Kindle HDX review but it is lighter, packs more pixels and with 100%RGB gamut.
    Reply
  • darwinosx - Wednesday, October 30, 2013 - link

    Its lighter because it is cheap plastic. It is also a far more limited device. Really laughable to think it compares to an Air. Reply
  • dsumanik - Wednesday, October 30, 2013 - link

    Read this review with a grain of salt. Anand lai shimpi is heavenly vested in apple stock, doing everything he can to boost the dismal situation.

    Thinner bezels and light weight do not hide the fact that functionally, this iPad is the same as the previous 2 generations.

    Sent from my ipad3, which will be upgraded when apple actually updates the product line.

    Here's some basic ideas mr cook:

    Wireless charging
    Fingerprint scanner
    Thunderbolt sync or usb3
    Haptic feedback
    NFC
    Reply
  • John2k13 - Wednesday, October 30, 2013 - link

    You know what's disgusting about your comment, and those similar to yours? That you basically accuse the author of being a liar, a shill, and completely lacking in integrity- without a shred of evidence. I read the entire 10 page review, and it was incredibly detailed, precise, and well-written, something that would be obvious to most sane, rational, objective people.

    "Anand lai shimpi is heavenly vested in apple stock, doing everything he can to boost the dismal situation."

    First of all, what "dismal situation"? Apple stock is up around $130 from a few months ago, or almost a third. Hardly "dismal". Also, do you think a single review from a website visited primarily by tech geeks is going to have any fucking effect on the stock? I mean, are you for real? Don't assume the author holds the same amount of ignorant stupidity that you apparently do, to think for a second this review would have a snowball's chance in hell in affecting stock. You clearly know nothing about how the financial market works.

    "Thinner bezels and light weight do not hide the fact that functionally, this iPad is the same as the previous 2 generations."

    Functionality on a tablet is primarily based on software, and the iPad has 475,000+ optimized apps which are getting more powerful all the time. The hardware simply enables better software. A tablet is basically a blank slate for the software, and better hardware helps in enabling better software. Every single aspect of this iPad is improved, so yes, it is more "functional". That list you made, though, is pretty ridiculous, and obviously a desperate attempt to list anything you can think of that the iPad doesn't have and pretend its significant.

    Wireless charging- why? This makes the device more functional, how?
    Fingerprint scanner- Wow, brilliant "idea". You probably mocked touch ID when it appeared on the 5S. Again, this would be nice to have I guess, but in no way impedes "functionality" of the tablet.
    Thunderbolt sync or usb3- I have no idea what "thunderbolt sync" means, and its pretty ridiculous you're harping on a USB3 port. It will never happen, nor should it.
    Haptic feedback- Utterly useless gimmick, but heym why not, right?
    NFC- I have NFC on my Nexus 4, and not ONCE have I even run into an opportunity or a reason to use it. But yeah, I'm sure you honestly think it's needed or useful on an iPad. Again, another meaningless bulletpoint you were desperate to add mindlessly.

    Next time you want to baselessly accuse an author of being a liar, a shill, a sellout, and having no honesty or integrity, try to make a coherent post that actually contains some intelligent, well thought out information. Otherwise, by attacking the author you just embarrass yourself as you did now. Grow up.
    Reply
  • ABR - Wednesday, October 30, 2013 - link

    Actually thunderbolt sync is one of the changes I'm really waiting for. Have you ever tried restoring even a 16GB iPad over USB? Slow agony. I can't even imagine what someone w/a 64 or 128GB model must go through. Even ordinary everyday syncs are far slower than what they could or should be. Reply
  • Howard Ellacott - Wednesday, October 30, 2013 - link

    You clearly don't realise what thunderbolt is, which is why that's such a stupid suggestion. Yes, faster syncs would be amazing, and restoring a 64gb iPhone is a right pain, but thunderbolt isn't the way. Reply
  • Kristian Vättö - Wednesday, October 30, 2013 - link

    USB 2.0 isn't the real bottleneck there, it's NAND. Most eMMC solutions can't even saturate the USB 2.0 link with sequential writes, so Thunderbolt or USB 3.0 would do absolutely. Reply

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