I've got a 2015 MacBook Air with 8GB of RAM and a 512GB SSD. I set the hibernation mode to 25 using the command 'pmset -a hibernatemode=25'. From what I understand, this setting should write the memory contents to the SSD and completely cut off all power, unlike hibernation mode 3 which keeps some power running. However, when I close the lid with about 45% battery and then open it two days later, the battery is down to 18%. Shouldn't this hibernation mode prevent any battery drain? I've checked the Apple documentation and it seems like mode 25 should stop all battery usage while hibernating. What am I missing?
1 Answer
What are you trying to achieve with the hibernation? Are you looking to preserve the exact state of your system while it's hibernating, instead of completely shutting it down?
I just want the system to work as it's supposed to. I could shut it down every time, but MacBooks are designed for quick use—just close it, then later open it to resume. Sometimes I won’t use my Mac for a week and I’d expect the battery to still have enough charge when I open it. I’m new to Mac but I know true hibernation from using Linux or older Windows. In those cases, my laptop resumes with nearly the same battery level after hibernation, so wouldn't I expect my MacBook to do the same with hibernatemode 25?