I would definitely recommend that you leave “Power Nap” disabled when you’re running on battery power, in case you otherwise forget and your computer consumes all the battery while you think it’s safely in sleep mode. On the main System Preferences window you’ll see this row of icons:Ĭhoose Energy Saver to proceed and it’ll show you how things are configured when you’re running on battery power: To start, go to System Preferences… off the Apple menu. Can be very weird if you’re not used to it, but it’s easy to disable if you want. However it evolved, Mac OS X now has what’s called Power Nap, a feature where even though your MacBook Air, iMac or other Apple computer is ostensibly asleep, it still wakes up sporadically to run administrative tasks including, yes, checking for new email. Well, perhaps that’s not entirely how it happened, because just about every modern Mac OS X system has included “Wake from sleep for network access” for a long time, and the computer had to be listening to know when that request had happened in the first place, right?
Some while back in the evolution of Mac OS X Apple’s development team decided to subtly change what it meant to “sleep” your computer and that went from being basically a power down feature that had the benefit of a very fast wake-from-sleep time to one where things were still happening even though you thought your computer was asleep.
