When the battery run down my mbp crashes off instead of sleeping

[motulist]

When my 2010 unibody mbp is running on battery and then the battery runs down to zero, instead of going to sleep the computer just acts like the power cord was pulled out on a desktop.

In other words, if I leave my mbp turned on overnight when it's not plugged into the charger, then when I wake up in the morning my computer is totally powered off, and when I turn it back on a message says the machine shutdown unexpectedly and the system clock is reset to the year 1901.

My main battery itself lasts for many many hours like its supposed to. Is there a backup motherboard battery that could be not working? How do I check that? And obviously that battery should still be working on a laptop that's less than 2 years old.

How do I make it act like its supposed to so that the computer goes to sleep when it runs out battery instead of shutting down unexpectedly?

 

[Macman45]

Try re-setting the SMC:

http://support.apple.com/kb/HT3964?viewlocale=en_US&locale=en_US

 

[motulist]

Try re-setting the SMC:

http://support.apple.com/kb/HT3964?viewlocale=en_US&locale=en_US

Sounds like a good idea, I'll try that. Is there any way to test if this was the problem without actually purposely running my battery down to zero again?

 

[Macman45]

Sounds like a good idea, I'll try that. Is there any way to test if this was the problem without actually purposely running my battery down to zero again?

Not that I can think of, but it's likely to be the problem.

 

[aarond12]

The only other reason I can think of (other than resetting the SMC which should work!) is that your hibernate file is corrupted. It's easily removed and is automatically recreated. From the Terminal (Applications/Utilities), enter this command:

sudo rm /var/vm/sleepimage

 

[motulist]

The only other reason I can think of (other than resetting the SMC which should work!) is that your hibernate file is corrupted. It's easily removed and is automatically recreated. From the Terminal (Applications/Utilities), enter this command:

sudo rm /var/vm/sleepimage

Thanks, I'll try that too.

EDIT:

This site specifies a slightly more specific directory location. Does it matter which of these paths I use in the command?

sudo rm /[B]private[/B]/var/vm/sleepimage

http://osxdaily.com/2010/10/11/sleepimage-mac/

 

[aarond12]

sudo rm /[B]private[/B]/var/vm/sleepimage

Those two directories point to each other, so they're really the same folder. Feel free to use either command.

 

[motulist]

Those two directories point to each other, so they're really the same folder. Feel free to use either command.

thanks

 

[motulist]

Whamp whaaaaa *trumpet fail noise*

I did both of those things, reset the SMC and deleted the sleepimage, but when my battery ran out just now the laptop simply crashed off instead of going to sleep. And when I turned it back on again it again said that my system clock's time was wrong and had been reset back to 2001.

How do I fix this?