Focus area includes Power Nap, which keeps your Mac updated during sleep

Sep 6, 2012 11:31 GMT  ·  By

Mountain Lion developers are being handed a new build of the 10.8.2 beta this week, along with instructions to focus their testing efforts on Power Nap, an exclusive feature introduced with Mountain Lion this year.

OS X Mountain Lion 10.8.2 Build 12C43 contains no known issues and surprisingly weighs in at 680MB for the both Delta and the Combo updates.

According to people who are familiar with the software, the new build asks developers to focus their attention on Power Nap, a feature exclusive to OS X 10.8 which enables portable Macs to stay up to date and perform automatic backups while in sleep mode.

“When your Mac goes to sleep, it still gets things done with Power Nap. It periodically updates Mail, Contacts, Calendar, Reminders, Notes, Photo Stream, Find My Mac, and Documents in the Cloud,” Apple states on the marketing pages of Mountain Lion.

“When your Mac is connected to a power source, it downloads software updates and makes backups with Time Machine. While all that updating is going on, the system sounds are silent and no lights or fans come on, so nothing disturbs you. And when your Mac wakes up, it’s good to go,” it adds.

The feature requires a Mac notebook with built-in flash storage. Examples include the MacBook Air line, and the all-new MacBook Pro with Retina display introduced earlier this year.

OS X 10.8.2 is the second incremental update lined up for users of Apple’s Mountain Lion operating system. Developers can download the new beta (build 12C43) over at Apple’s Mac Dev Center.

OS X 10.8.1, released last month, resolved issues that caused Migration Assistant to unexpectedly quit, improved compatibility when connecting to a Microsoft Exchange server in Mail, and improved 802.1X authentication with Active Directory credentials, to name a few changes.

During testing, it had been reported that OS X 10.8.1 would fix a widely-reported battery drain issue on Mac notebooks. However, upon launch, only a handful of customers noticed improved battery life as a result of applying OS X 10.8.1.

The Power Nap feature may just be the culprit. We'll just have to wait and see.