What is the battery life of the "Mid-2012" MacBook Air models in "real-world" usage tests?

Apple's official battery life estimates for the "Mid-2012" MacBook Air models -- the MacBook Air "Core i5" 1.7 11-Inch and MacBook Air "Core i5" 1.8 13-Inch -- are five hours and seven hours of runtime, respectively. The 11-Inch model has an integrated 35 watt-hour battery and the 13-Inch model has an integrated 50 watt-hour battery. Neither is intended to be replaced by the end user.

Photo Credit: Apple, Inc. (Left - 11" MacBook Air, Right - 13" MacBook Air)

Official Battery Life Testing Criteria

In fine print, Apple expands that the battery life estimate is using preproduction versions of the stock configurations performing a "wireless web" test. The company further explains that the "wireless web test measures battery life by wirelessly browsing 25 popular websites with display brightness set to 50%." and also disclaims that "battery life varies by use and configuration."

Both the 11-Inch and the 13-Inch model can be custom configured with a faster 2.0 GHz Core i7 (I7-3667U) processor as a "configure-to-order" upgrade, but battery life is the same. For convenience, EveryMac.com also lists these CTO configurations as their own models.

In recent years, Apple's official battery life estimates have been reasonable, but readers still ask and test results from independent third-parties still are worthwhile.

Third-Party Battery Life Test Results

Independent testing methods vary and can provide a good idea of battery life in different scenarios.

In its review, Engadget evaluated the 13-Inch model and found:

The [1.7 GHz Core i5-powered 13-Inch] 2012 Air lasted six hours and 34 minutes in our rundown test, which involves looping a video with WiFi on and the display brightness fixed at 65 percent (in the case of Macs, 10 out of 16 bars). That's about an hour longer than what we got when we ran the 2011 Air through the same test last year.

It is important to note that this "rundown test" is considerably harsher than Apple's official testing, but the results still are quite respectable.

Slashgear performed a similar test on the 13-Inch model -- but with reduced display brightness and Bluetooth on -- and received slightly worse results:

In our testing, with brightness set to 50-percent and WiFi and Bluetooth turned on, continuous browsing (loop test), we were able to stream a 2-hour long video once while playing a looped video for a total of 6-hours and 18-minutes before the battery ran out.

MacWorld tested both the 11-Inch and 13-Inch models with its standard test -- playing a movie file "in full-screen mode at full brightness, connected to a Wi-Fi network, with the backlit keyboard dimmed, and volume on 2" -- and reported:

Roughly four hours of battery life for the 11-inch Air (slightly better than the 2011 model’s battery life), and around five hours of use for the 13-inch Air (about the same as its predecessor).

Battery Life Summary

Ultimately -- just as they have been for other models in recent years -- Apple's official battery life estimates for the "Mid-2012" MacBook Air models are reasonable -- five hours for the 11-Inch models and seven hours for the 13-Inch models -- for basic productivity use and surfing the web without Flash. As always, however, in actual use, battery life can vary.