I've noticed that when I close my MBA that the battery will drain overnight from 100% to less than 10% if my Win7 Parallels VM is running. I've tried a number of different problem determinations with Apple support but they haven't been able to find out what it is. If I suspend the VM prior to closing the MBA battery drain is much less - only 2 -3%. Is there any configuration options that needs to be set on the Win7 VM to make it play nice with OSX sleep? I'm running Parallels 9 for Mac, Build 9.0.24217 (Revision 979618; Tuesday, February 25, 2014) on OSX 10.9.2 on a MBA late 2013.