I've always thought that my 8GB SleepImage was useless since I will never be in a situation where I would loose power in Sleep mode, so I disabled it on my '13 MBA (13"/i7/8/512).
But after a few days I re-enabled it for power reasons. Without a SleepImage, the MBA keeps the RAM 'alive' in Sleep mode pass the default 4200 seconds (70 minutes) since it can't write the contents of RAM to it and won't go into a deep sleep to save power.
The results of no SleepImage were quite impressive: my 12-hour capable battery lost about 25% of juice per period of 8 hours in overnight Sleep mode 😱
Since I've restored the SleepImage, an 8 hours Sleep period will cost in the ball park of 2 to 4% 😎
But after a few days I re-enabled it for power reasons. Without a SleepImage, the MBA keeps the RAM 'alive' in Sleep mode pass the default 4200 seconds (70 minutes) since it can't write the contents of RAM to it and won't go into a deep sleep to save power.
The results of no SleepImage were quite impressive: my 12-hour capable battery lost about 25% of juice per period of 8 hours in overnight Sleep mode 😱
Since I've restored the SleepImage, an 8 hours Sleep period will cost in the ball park of 2 to 4% 😎