Apple has seeded a second build of OS X Mountain Lion 10.8.1 to developers.

The beta, build 12B17, has no known issues, and Apple has asked developers to focus on Active Directory, iCal, Microsoft Exchange in Mail, PAC proxies in Safari, SMB, USB, and WiFi and audio when connected to an Apple Thunderbolt Display, reports 9To5Mac.

There are currently no release notes included in 10.8.1 seeds, so we don’t yet know when the update is expected to be available for the public to download.

It is hoped that the update will address MacBook owners’ battery drain concerns, as well as the Save As behaviour, which saves both the original file and also creates a new one.

The new operating system, which was released on the Mac App Store in July, was downloaded more than 3 million times within four days of its release.