06-21-2008, 04:09 AM

I get the usual 'reserve battery power' warning when there's few minutes left before the battery is about to run out. Then, the power cuts. No safe sleep at all; it's as though the battery has been yanked out. When I put the charger in, and start it up again it's as if I've just restarted the computer i.e. it didn't remember my previous state

My HD has got over 10gb free space remaining, so there's definitely enough room for a 'sleep image'.

Has anyone come across this, and does anyone know of any possible fixes?

Thanks in advance.

I'm running 10.5.3 (latest updates), on a Macbook 2GHz Core2Duo, 2GB RAM. Standard/popular applications

06-21-2008, 06:55 AM

Originally Posted by StevenH

I get the usual 'reserve battery power' warning when there's few minutes left before the battery is about to run out. Then, the power cuts. No safe sleep at all; it's as though the battery has been yanked out. When I put the charger in, and start it up again it's as if I've just restarted the computer i.e. it didn't remember my previous state

My HD has got over 10gb free space remaining, so there's definitely enough room for a 'sleep image'.

Has anyone come across this, and does anyone know of any possible fixes?

Thanks in advance.

I'm running 10.5.3 (latest updates), on a Macbook 2GHz Core2Duo, 2GB RAM. Standard/popular applications

What happened to your computer was normal...

Your battery died. It happens to mine too. OS X really should go into sleep mode at around 3%.

When your computer goes into sleep mode (when you close the lid) the contents of your ram is written to your hard drive. that is the "sleep image"
You'll notice that there is a noticeable time gab between when you close the lid of your computer and when the sleep led starts pulsing... that's the sleep image being written...

if your computer were to run out of battery when it was asleep, the next time you plug it in and turn it on, the sleep image will return and you should not have lost any work...

however, in your case, your computer was turned rather then sleeping when it ran out of battery, therefore there was no sleep image to return to...


now you may be asking, "Why does the computer not make more sleep images (say, every minute) just in case the computer were to turn off."

A sleep image takes a while to be written. In my case with 4gigs of ram it takes 30sec.
So, it would not be practical for OS X to take 30sec to write a sleep image every minute of so...



So there you go
Hope it makes sense

06-21-2008, 08:19 AM

This happened to me as well a few months ago, all of a sudden my macbook would not go into safe sleep mode.

I entered this terminal command to enable it again:

sudo pmset -a hibernatemode 3

I'm not sure why safe sleep was disabled but it did, I entered that terminal command and it worked after that.

Note: you may have to restart your mac for the changes to take effect.