I've been an iStat menu user since I got my first Mac mini last 2010, and I have been using it in my recent 2013 13" Macbook Air too. Now, the battery remaining iStat is telling me is waaaaaaaay off from Apple's Energy Saver. iStat's Equivalent on Apple's (taken the same time) iStat's - another scenario Apple's They do have the same battery remaining if it goes lower than 9:00 remaining though. One last question irrelevant to the topic. The number of seconds my machine boots up and shuts down sometimes vary. Is this a normal thing? Do I need to reset my PRAM every time this is happening? The thing is, it's kinda annoying.