2013 MBA Battery Life #

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I’ve been using an older (2011) 11″ MBA with very poor battery life (~2hrs?) and have been very much looking forward to upgrading to a Haswell MBA for quite a while.

TLDR: battery-life is much improved, however falls far short of the claimed 9 hours for my 11″ MBA. I get about 6hrs max (6hr 12min) and in regular usage, less.

The specific model I have is the top-of-the line MacBook Air “11-inch, Mid 2013” with a 1.7GHz Core i7 processor, 8GB RAM, and 512GB SSD. Here’s the iFixit teardown. Anandtech did a recent test comparing Core i5 to Core i7 battery life (the Core i7 is very slightly better under low workload, and is 13-18% worse under medium-heavy workload).

The battery is spec’d by Apple at 7.6V and 5100mAh – 38.75Wh, 8.08oz. The battery had a Cycle Count of 6, a Max Capacity of 5326mAh (4.4% above spec) and an initial voltage of 8.545V – that’s to say it’s in better-than-spec condition.

Display was set to 75% for testing with the keyboard backlight off, wifi on, screen sharing off, SSH on.

Background apps include: Dropbox, iStat Menu, Evernote Helper, MiniBatteryLogger, and memcached (64MB, not being used).

The 6hrs was spent almost entirely with light web browsing w/ relatively low CPU/disk/network usage. It’s too bad there isn’t anything like Android’s battery/activity tools built into OS X (I suppose you could script something to sample/aggregate activity but that’s sort of beyond the time I really want to spend on this since I can’t really do much w/ that data).

I used MiniBatteryLogger 1.8.5 for getting battery stats and for graphing. Also here’s some clips at the end from iStat Menu:

For those interested, here’s the raw battery data export.

UPDATE: MacWorld also did a comparison of the i5 vs i7. Macrumors has a very long 2013 11″ Battery Life Thread (real world)

UPDATE2: The Verge published an 11″ review where they claimed to get 9-10hrs+ of battery life (cycling through popular websites at 65% brightness). gnoring any critiques on the battery testing methodology, I really wish I could find the disparity – getting that sort of battery life would be really nice… Things that could possibly be responsible for the difference:

  • Actual browsing uses a lot more network than refreshing a series of mostly cached sites
  • FileVault chews up a lot more power
  • Wifi signal/AP distance/type has significant difference in power consumption
  • Some long-running process, either ClipMenu, iStat Menu, Dropbox, SSH is causing my laptop to function way less efficiently than it should.
  • http://edward.oconnor.cx/ hober

    Out of curiosity, what web browser were you using? The Verge measured a 2 hour difference between Safari and Chrome (13 hours and 29 minutes of battery life running Safari, but only 11 hours and 29 minutes running Chrome): http://www.theverge.com/2013/6/17/4436332/macbook-air-review-13-inch-2013

  • http://jasoncosper.com/ boogah

    I’ve heard of Chrome users getting better battery life on the new MBA when turning “click-to-play” on for Flash & Java. If you haven’t already done it, maybe it’s worth a try.


  • http://randomfoo.net/ lhl

    Yep, I use Chrome. Might be worth considering switching, although Safari doesn’t support some of the extensions I use regularly. I wonder how Firefox compares…

  • bjj

    I have the MBA 2013 11″ with the i7 process and 8GB of RAM with the default 128GB SSD.

    I am getting far below the advertised benchmarks – roughly 4 hours with basic web browsing on safari with no flash installed whatsoever. Further, I have no installed any applications as of yet.

    I highly recommend to stay away from your purchase for a few more weeks until reviews like mine get more attention.

    In terms of sheer processing performance it is what you would except from any computer running an SSD with tons of RAM and a UNIX OS.

    Overall verdict from my personal experience is that you shouldn’t be too optimistic on the official benchmarks.

    My personal suggestion is to go for another brand that also utilizes Haswell for a fraction of the price. Like any Apple product, we are mostly paying for the brand.

  • http://randomfoo.net/ lhl

    I don’t think I hit any sites using Java – I also have Adblock Plus blocking everything so stray Flash is usually not a problem. hober’s point about Safari vs Chrome is interesting. I suspect that Mavericks will improve battery life – I wonder how that’d affect the browsers…

  • bjj

    I called Apple Support to let them know of my benchmarks result:

    – Sorry you are having this trouble

    – Let’s take a look at your maximum charging capacity in addition to your current cycle count

    – Cycle Count: 20, Full Charge Capacity (mAh): 5110

    – Looks like you may have some background processes eating away at your power supply

    – Okay, you don’t…

    – Would you like me to schedule you an appointment with an Apple Store genius?

    – Good bye.

  • http://randomfoo.net/ lhl

    I think you might misunderstand – I bought mine as soon as it came out. My MBA is also a “clean” install – the first time in years. Despite this I still having weird occasional wakeup lags (I wonder if this is a FileVault issue) and of course, well-below claimed battery life.

    What’s interesting about this is that my poor real-world battery life seems to be contradicted by many of the reviews by third party sites (The Verge, AnandTech, Ars Technica) – most of these are reviewing the 13″ but it’s strange that while those have been near or even exceeded claimed battery-life, mine falls far short, even when I’m barely doing anything with it.

    All that being said, the 11″ MBA is still my best option… Besides OS X, which I still find much more pleasant than the alternatives (and allows me to run a bunch of software like XCode and Photoshop that I really need to do my job), the combination of form factor, build quality and the execution of essential and seemingly basic things like a decent trackpad seems to be unmatched.

    Anything else that comes close: Google Pixel, Sony Vaio Pro 11 are priced similarly (or more expensive!) and have significant tradeoffs. BTW, I don’t think you’ll get anything similar in weight/build quality/features at the 11″ or 13″ form factor for a “fraction” of the prices of the MBA – most of the PC alternatives are *more* expensive.

  • http://randomfoo.net/ lhl

    I might recommend using MiniBatteryLogger and comparing the Amperage usage to mine at least as a baseline – 6hrs isn’t 9hrs, but 4hrs is still significantly worse. Honestly, it does seem like something that you should either get looked at, or return…

  • philipn

    Great writeup, thanks for this! I’ve read this report of Dropbox eating lots of battery (http://blog.nicoschuele.com/?p=151), but I think that’s probably not true in your case — they were seeing a lot of CPU activity when the Dropbox daemon was doing its thing.

    Also, I wonder if this is somehow dependent on what kind of WiFi network you’re connected to. I know all the more advanced WiFi cards can do this fancy power saving stuff, but not all access points support it.

  • http://randomfoo.net/ lhl

    Hmm, I’m using a Netgear WNR3500 running Tomato firmware which supports WMM so I don’t think that’s it.

    The Dropbox thing *is* interesting. I didn’t notice it at the top of the CPU charts (glancing at iStats Menu’s CPU meter it was usually “Google Chrome Helper” processes at the top w/ occasional kernel_tasks and the like, I may have to run it again.

    It’d be really nice if there were a sampling tool that could do a good job gathering all the relevant data together into a single picture for battery usage. Sampling/reading from ioreg for battery readings (it’s mostly straightforward but the Amperage numbers are wonky) and that could also look iostat/lsof/nettop/vnstat/process lists and calculate which could do a reasonable job targeting which processes were hogging network/cpu/disk etc. I wonder how exactly the Android “Battery” stats works…

  • Robert

    Hi, I’ve also got the Haswell MBA mid2013 and it’s a great machine. But this night battery run down in sleepmode from 95% to 50% overnight. Which is kind of wired. I found out that running chrome or safari on facebook sucks out battery as hell. On this blog: nothing. Still up to 14 hours of battery life. If I close facebook iStats shows me that the battery isn’t sucked out at all. Facebook really needs battery which is wired. I am not good at guessing which process on facebook sucks out the battery life (chat is turned off). Also youtube just kills it when I start playing video which isn’t that normal. So maybe its flash on the new macbook air? But I remember watching youtube videos for hours not thinking about batterylife. Its just since two days. I am confused. Robert

  • http://randomfoo.net/ lhl

    Facebook will affect your battery life because even w/ chat turned off it is constantly polling (talking to FB servers) to update status updates. Seems to average about 5% of my CPU when running. There might be some ads or other things that are running (I block a lot of stuff so I can’t really tell). In Chrome you can go to Tools > Task Manager to see memory and CPU usage per tab. That may help diagnose your video issues too. Good luck.

  • slevinz

    Hey what’s up random!

    I came across this site to be one of the most detailed with their battery tests, from light to heavy workload: http://www.anandtech.com/show/7085/the-2013-macbook-air-review-13inch/6

    How’s it on the Mavericks? I’m really looking into getting one (MBA 11”), mostly using for work, web dev, what would u recommend at this time, would 4gb ram be enough, and the screen size?

    – sy7ar

  • http://randomfoo.net/ lhl

    Hey, just saw this message. Mavericks is great and gives a big battery life boost. I did a followup post here: http://randomfoo.net/2013/11/08/more-on-os-x-mavericks-power-usage

    4GB is ok, but it’s soldered in so I went for 8GB both for future-proofing and since I tend to have lots of tabs open. I’m a big fan of the MBA 11″ for compactness, since I like to carry it around everywhere, but the new Retina 13″ MBPs are actually not that much weight and the screen is pretty great (3.5lb vs 2.4lb). iPad Air is 1.0lb and iPad Mini is 0.7lb by comparison. For web dev/office work, either is fine, but I’d consider the 13″ rMBP if you were using much photo/graphics work, or if you were using that as your main computer or if ultraportability wasn’t as big a factor.

  • slevinz

    I couldn’t wait so I’ve bought it for a week or so already and it actually handles everything well with only 4gb ram. Granted, I use it more conservatively keeping only a few tabs open at a time, but that’s because I have a kick ass desktop to do all the heavy works like browsing with 30+ tabs and sometimes photoshop .

    But yeah, Macbook air’s been my dream machine for a long time and I’m happy to finally get my hands on this beauty. Since I mostly only use terminal, write code with sublime text, and googling from time to time, I’d say it’s more than enough with the current spec.

    Friend told me he’s gotten worse battery with Mavericks but hearing from you I’ll probably upgrade it soon. With that in mind, what are some (significant) benefits from upgrading to Mavericks other than boosting batter life?

  • http://randomfoo.net/ lhl

    Hmm, you bought a new MBA and it didn’t have Mavericks preinstalled already? Weird.

    Besides the noticeable bump in battery life (like, a lot, although it has to reindex and stuff so the first day may be worse) it also has a bunch of performance improvements so should actually be faster than Mountain Lion as well. I didn’t notice too many other changes – a few new apps. The new Safari is much nicer than the old one. And multiple display stuff is fixed (Lion broke a bunch of stuff)

    I had to switch to Airmail for my Mail App (Mail.app in Mavericks broke GMail handling) and there were some early MacPorts niggles but overall I haven’t run into any major problems, which is nice.

    BTW, if you’re new to OS X, I consolidated/put up an updated list of my must-have apps here: https://randomfoo.hackpad.com/Mac-Apps-XAZw6MLeL4x