updated 01:41 am EDT, Tue June 10, 2014
Fix prevents excessive battery drain when lid is closed during operation
Apple on Monday issued a MacBook Air SMC Update version 2.0 specifically for the next-to-most-recent (otherwise known as the Mid-2013) MacBook Air models. The update, which requires users be running either OS X Mavericks 10.9.2 or later or OS X Mountain Lion (10.8.5), corrects an issue that may "cause the battery to drain faster than expected when the lid is closed," says the company. The 804KB update file revises the firmware of the MacBook Air, and thus the computer must be plugged into a power source for safe updating.
Apple recommends that the unit be plugged in or have a minimum charge of 25 percent or more before attempting the firmware upgrade. Installing the package will cause a restart, with a status bar to indicate the progress of the update. "Your computer's fans will run at full speed during the update but will return to normal speed once the update completes," Apple notes in its instructions. As with all firmware updates, the company says uses must not "disturb or shut off the power on your computer during this update."
The file is available through Software Update for owners of the correct model of MacBook Air, and can also be downloaded in a standalone installer form from Apple's support web pages.