Thank you for being a valued part of the CNET community. As of December 1, 2020, the forums are in read-only format. In early 2021, CNET Forums will no longer be available. We are grateful for the participation and advice you have provided to one another over the years.

Thanks,

CNET Support

General discussion

MacBook Pro loses battery charge with cover closed

Nov 12, 2010 6:52PM PST

I just bought a new MacBook Pro with a solid state (flash memory) disk. The battery life is good while I'm using it, but if I leave it with the cover off for a few days (asleep, I assume), it'll be mostly discharged when I open it up. I assume this isn't normal - it shouldn't be losing that much charge when closed and hibernating. I don't have "wake for ethernet access" checked, if that makes a difference. What's going on - why won't it hibernate?

Mike

Discussion is locked

- Collapse -
Under warranty,
Nov 12, 2010 9:39PM PST

call Apple and tell them about this.

P

- Collapse -
When you close the lid
Nov 13, 2010 12:00AM PST

When you close the lid on an Apple laptop it first goes into a suspend to RAM state Apple calls "Sleep mode". You can tell it's in this mode because you'll have a slowly pulsing white light visible on the front face of the system.

In this state, the system is effectively turned off, except for the RAM which is kept active, and some circuitry needed to power the system back up.

Now, if your battery gets to critical levels during this time, it will go into what Apple calls "Safe sleep" IIRC, and everyone else calls Hibernate. It will dump the contents of RAM to disk, and shut the system off completely.

For better or worse, there is no way to dictate that the system should go into safe sleep when you close the lid, not merely sleep. So if you know you're not going to be using the system for a couple of days, just shut it off. Having to wait 30-90 seconds for the system to boot back up about once a week is not that big of a hardship. Start the thing booting, go get some coffee or something, and by the time you get back, it'll probably be ready.

And when you think about it... When the system is running you get maybe 4-8 hours worth of battery life. In sleep mode you're getting over a 48 hours. Sounds like pretty good battery life to me. Nothing at all seems wrong here, except your expectations.

- Collapse -
Mac in sleep-mode
Nov 28, 2010 10:46PM PST

I think your advice is right on, Jimmy. I have left mine on with the cover shut for brief periods and it does lose some charge, less than when open. If I am not going to use it over the next couple of hours, off it goes!

- Collapse -
mine too
Nov 19, 2010 10:53PM PST

Hello- My Mac does the same, which i assumed was fine as battery life is usually lost in sleep mode, just way slower. I never tripped on it. However, I usually shut my notebook off if not planning to use for a few hours or more.- Linnea

- Collapse -
same here
Nov 27, 2010 12:49PM PST

Whenever I don't use my mac I always make sure that I turn it off for overusing it and not turning it off may affect its motherboard or other parts, just letting your laptop sleep won't do good you have to turn it off whenever your not using it

- Collapse -
How so
Nov 27, 2010 11:24PM PST

How so? You say turning it off and on may affect the logic board, so as an ACMT who fixes Apple laptops and desktops professionally, I'd be quite interested in hearing how this is so, given I've never come across it until now.

- Collapse -
hi
Dec 4, 2010 10:06AM PST

Like us these machines needs to take a rest overusing them may destroy their system, my friend gave me this piece of advice while I'm still using a PC well I think its just the same for all of the gadgets. Some MP or any laptop users are just letting their laptop in sleep mode when not using them instead of shutting them down. This practice may ruin your precious laptop's system.

- Collapse -
Not really
Dec 4, 2010 10:39AM PST

Not really. You can make an argument for using electricity needlessly, but it doesn't really harm the system. Especially these days, when laptops always go into a low power mode when the lid is closed by default.

Sleep mode may wear out the battery a little faster, but other than wasting a little electricity needlessly, there's no real harm to the system. Sorry to say, but your friend is full of it on this one. Maybe 20 or so years ago he'd have had a point, but certainly not today.

- Collapse -
Thanks
Dec 4, 2010 6:56PM PST

Now I can lecture my friend about it, thanks for imparting your knowledge with me :}

- Collapse -
soooo
Dec 10, 2012 11:09AM PST

I have a one year old MBP and I find that it uses about 15% battery just being closed and asleep in day. I've never noticed this before. Any thoughts on this? EX. I charged fully last night and unplugged before going to bed with it closed and asleep. Checked it this morning, about 7 hours later and its at 85%. I don't see any reason for it to be using that much battery.

- Collapse -
(NT) Why would you unplug it when you went to bed?
Dec 10, 2012 8:48PM PST
- Collapse -
I'd leave it plugged in. (more follows)
Dec 12, 2012 1:39AM PST

There is some misinformation out there on the net about leaving it plugged in wears out the battery or even more outdated information about overcharging the battery.

Those issues were quite true in early laptops and the NiCad battery days. Be sure you are not reading old issues or getting advice from non-engineers.

At the office we've had laptops plugged in, on desks for years. A few were 4+ years old and when they came off the desk the battery surprised us with more than 50% capacity. Since these batteries were only 300 cycle units we were happy.
Bob