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


View All Comments

  • tetsuk - Friday, November 15, 2013 - link

    The Macbook Air is great. However, as you mentioned, iWork is not comparable to Office. Since bootcamp works really well, it could still be an option. Reply
  • syedjalalt - Tuesday, November 5, 2013 - link

    AnandTech reviews are so unbiased and true unlike The Verge(iSheeps). They go as much deeper as possible to get the best out of their reviews and articles. This is real journalism. Hats off. Reply
  • johned - Tuesday, November 5, 2013 - link

    I have a Nexus 4 (soon to be 5) a Nexus 7 first gen and an iPad 2 (soon to be Air). Sometimes I find all the partisan bickering about this stuff hilarious. I like a good row as much as the next guy but I'm a geek. I just love to play with the stuff. I prefer Android to iOS for my daily driver phone, but come on. Anand seems like he's just like me. He loves the tech, all of it, and if had could articulate the way he does, I probably would've started a website like this myself.
    I will say this, I really don't understand why people think NFC is dead. I use it at least once a day with Google Wallet on my phone. Both major grocery store chains in my area take it. McDonald's takes it. Now, the carrier based service is tanking because they were greedy and botched it. Google wallet I find very useful, though.

    Also, I've never had problems transferring files with it. My brother-in-law has a VZW Droid M and I have Nexus devices and I've sent him files from both my tablet and my phone. The most useful thing about it compared to Apple's Air Drop service is that I can do this without needing a wifi connection.

    I can honestly say, that the one thing keeping me from an iPhone right now is NFC because I use it so much. If the 5s had included it, I would be sporting one right now. Google Wallet is already available for iOS.

    I keep seeing somebody in here sounding like the Apple App Store marketing manager spewing the tired old line about 400blah blah thousand "iPad optimized" apps. This is nice that they are doing that but I observe two things.

    1) Google is trying to standardize apps so that 1 app needs to be made for all devices. Since all current Nexus devices have either a 720p or 1080p display, this is easy. This is simply a different approach than Apple is taking.
    2)This means that I only need to buy every app 1 time instead of buying it once for my phone and again (usually for a higher price) on my tablet. Apple could mitigate this buy shipping a standard hi-def resolution on the iPhone which they seem reluctant to do.

    Back to the original point. We are all geeks here. I appreciate technology. I have opinions about what I like and don't like, but I come to Anandtech because I like to stay current on everything going on. This site also stays largely unpolitical and sticks to the tech, which is why I don't read Ars as much anymore.
  • JTravers - Wednesday, November 6, 2013 - link

    Not sure what you mean about needing a wifi connection for AirDrop. Is having your wifi turned on an issue? AirDrop uses wifi direct, so although you do need to have your wifi turned on you don't need to be connected to a wifi hotspot. Reply
  • nedjinski - Tuesday, November 5, 2013 - link

    but wait - there's more -
  • Mayuyu - Wednesday, November 6, 2013 - link

    IGZO display instead of IPS. The chart here is wrong. Reply
  • cheshirster - Wednesday, November 6, 2013 - link

    Windows tablets are going to suppress ipads sales in coming months.
    Still no mention in conclusion. That's hilarious, at some point.
  • AngryCorgi - Thursday, November 14, 2013 - link

    Again, you are listing the #s for GFLOPS/core, not the total GPU GFLOPS on the Rogue chips. You need to clarify that. And the older 554MP4 was 21.6 GFLOPS @ 300MHz (14.4 GFLOPS @ 200MHz, as ID'd by Imagination Tech). Reply
  • Atlink - Saturday, November 30, 2013 - link

    I'm truly not trying to stir the pot at all, but I am curious about NFC. I understand what it is, and its possible application, however, I'm not seeing anyone really clamor for it. This whole NFC deal seems like the HD-DVD/Blu-Ray war all over again. Neither side really had a lead until Sony began to tip the scales in their favor due to the PS3's exclusive use of Blu-Ray discs for games.

    I understand that NFC can be used to do some neat things: pay for food, verify a subway ticket, check into a hotel, etc. The problem that I'm seeing is one that anyone without a NFC phone can see: the lack of NFC-enabled terminals. I would say that Apple is dropping the ball something fierce if there were NFC terminals to scan this and that almost everywhere, but like QR codes, they seem almost like a novelty. I *could* scan that code with my phone by either downloading an application that can do it, and then hoping that the code can be read by the program, and hoping that the URL is worth looking at... or I could just type in the URL right below it (yes, I know not everything has a short URL below it). I *could* use NFC by sitting down with my credit cards in advance, creating an account, punching in the numbers, verifying data, opening the app when needed, sorting through the cards I plan to use, selecting the correct one, ensuring the transaction was accepted by the POS... or I could just use my debit card like I have been doing for years now, swipe once, punch in my PIN, and be done with it.

    Like I said, I do think that NFC is a really neat idea, and I would love the saturation to become more prevalent in the US, but as of now, it's kind of a neat idea with no real, practical application. I guess the problem I'm having is trying to understand the importance of having it NOW. Some people use NFC as a selling point, and that just seems odd.

    I think that when NFC catches on, and you begin seeing it almost everywhere, then we'll start seeing it in Apple products. No point in putting something in if you aren't going to be able to use it, right?
  • divps - Saturday, November 30, 2013 - link

    I have a Nexus 7 and use an iPhone 5. We also have the iPads, a Nexus 4, a Nexus 5 and a Galaxy Nexus phones in the household. I use the Nexus 7 as my tablet for the things that it is strong at and use the nice iOS ecosystem for Apps that I need and that's generally good enough for me. I like the idea of wireless charging and I'm going to get a wireless charger for the Nexus 4 and Nexus 5. The Micro-USB connector isn't the easiest thing to connect without a little effort and the connector can get fatigued over time. It's also nice if you can just come home and put the phone on the platform and pick it up when you need it. The Apple connector is a lot easier for me to put in but wireless charging would mean that I wouldn't need as many lightning cables at home.

    The Apple ecosystem is generally smoother and nicer. I recently upgraded my Nexus 7 to KitKat and it ran like a dog and I tried a bunch of things and eventually had to do a factory reset which means that I lost a bunch of things and had to re-add them. There are several threads on this on the Phandroid Nexus 7 forums. The iOS 7 upgrade was a piece of cake compared to the KitKat upgrade. I also found UI differences for some simple things between the Nexus 5 and Nexus 7 on KitKat. On the Nexus 7, you do left and right pulldown for notifications and settings. On the Nexus 7, you do one-finger and two-finger pulldowns for notifications and settings. I had thought that the UIs would be the same but I guess not.

    I'm extremely impressed with the Nexus 5 hardware - it's very, very fast, great screen, very thin, good feel in hand. I don't like the layout of the volume control and it has known problems with shutter lag and audio output (which I hope will be fixed with software). It's an incredible value for the money.

    The thing that I like about Android is the ease of copying content over to them. You just plug them into a PC and drag and drop your files and the Apps will find them on the device. With iOS, I have to convert videos to MP4, or documents to an iBooks compatible format.

    I think that the music player and email apps on iOS are far better than the OS provided ones on Android. Google should have done a better job copying iOS Apps there.

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