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Charged Battery looses 1% over night

P

Primusz

macrumors newbie
Original poster
Mar 13, 2008
19
0
Hi Everyone,

I got my MBP 2,5 Ghz Penryn 3 weeks ago and it's my first Mac.

However I noticed something funny. I work at my desk 99% of the time, with the power plugged in. Ofcourse, the battery should remain fully charged because of this, but when I start it up the next morning, the battery has lost 1% charge.

How can this happen? I am using the adapter as much as possible to prevent the battery from having to charge and recharge so much, extending it's life.

Any ideas?
 
Lithium Ion batteries can be damaged if they're kept at 100% charge, so to prevent this your mac will automatically charge and discharge between about 95-100%, this is normal.
 
zaney said:
Lithium Ion batteries can be damaged if they're kept at 100% charge, so to prevent this your mac will automatically charge and discharge between about 95-100%, this is normal.
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thank you for this constructive and useful feedback!

needless spelling quote removed by a mod
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why are you telling me this?
 
Completely normal. Have a 4 year old battery in a ibook that looses
3-4% overnight, but still works fine.
 
The battery contains a processor, which draws a small amount of current from the cells when they aren't being charged. This occurs even when the laptop is plugged in since no power is supplied to the battery during times the battery is not being charged, so the processor needs to draw off from the cells. The processor is on the same circuit board those green LED's are on.

Edit: Like a previous post above said, it is not good to keep a Lithium ion battery at 100% over long durations. If you don't plan on using it for long durations (e.g. more than a week), drain it to 60%, remove it from the laptop, and store it in cool place (e.g. a refrigerator). This will keep the battery fresh from degradation for months at least, and I've seen data that suggests years.
 
As above people had said the battery will allow itself to dip to 95%. Also since you mac is approaching being around for a month it is coming up to the time you might want to cycle the battery if you aren't letting it completely discharge as you go. You may already know about this but just in case the apple doc below lets you know how to do that:

http://docs.info.apple.com/article.html?artnum=86284

I do this about once a month my battery is up to 70 cycles and it hasn't lost a mAh in its life yet...cross fingers.

Cheers.
 
Needless spelling stuff
Click to expand...

A) He was asking a valid question, you knew what he meant.
B) Looses and Loses are both valid words, and thus a spell checker won't help.
C) O -> OO is an easy typo to make.
D) This is the internet, and thus it's presumptuous to assume that English is someone's first language.
 
Mod Note: This is a global forum and as hinted by other members in this thread communication is the goal not perfert spelling. Please refrain from commenting on spelling mistakes as it generally derails a thread thus making it harder for the original poster to get answers. I know I spelt (yes it is a word) perfect wrong


In regards to the original question, IIRC the battery is charged up to 100% and then the charger stops until the charge dips below 95% then it tops it up again.
 
It is a bad idea to operate your Apple portable without the battery because this will automatically throttle the processor down to one core. As others have said, don't worry about the battery draining down slightly, it is just to protect it from damage.
 
iCeFuSiOn said:
It is a bad idea to operate your Apple portable without the battery because this will automatically throttle the processor down to one core. As others have said, don't worry about the battery draining down slightly, it is just to protect it from damage.
Click to expand...

Where did you read this, can you cite it or provide a link to it? I suppose you aren't talking about the "Reduced" option in the Energy Saver system preferences.
 
Edit: Like a previous post above said, it is not good to keep a Lithium ion battery at 100% over long durations. If you don't plan on using it for long durations (e.g. more than a week), drain it to 60%, remove it from the laptop, and store it in cool place (e.g. a refrigerator). This will keep the battery fresh from degradation for months at least, and I've seen data that suggests years.
Click to expand...

Well, that seams a pretty over-the-top thing to do, and as suggested, it would mean one core would be turned off

As above people had said the battery will allow itself to dip to 95%. Also since you mac is approaching being around for a month it is coming up to the time you might want to cycle the battery if you aren't letting it completely discharge as you go. You may already know about this but just in case the apple doc below lets you know how to do that:

http://docs.info.apple.com/article.html?artnum=86284

I do this about once a month my battery is up to 70 cycles and it hasn't lost a mAh in its life yet...cross fingers.
Click to expand...

thanks for the link! Is it also applicable for the MacBook Pro?

zaney said:
No problem, and beware the grammar nazis. I must admit that bad spelling/grammar does annoy me, but not to the extent that I tell people off over loose/lose, which is probably a just typo.
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A) He was asking a valid question, you knew what he meant.
B) Looses and Loses are both valid words, and thus a spell checker won't help.
C) O -> OO is an easy typo to make.
D) This is the internet, and thus it's presumptuous to assume that English is someone's first language.
Click to expand...

thanks for your support guys/gals, but I don't seem to see the word loose and lose being used in my post. Only the world "lost" , which is in the proper context if you ask me?
 
Primusz said:
thanks for your support guys/gals, but I don't seem to see the word loose and lose being used in my post. Only the world "lost" , which is in the proper context if you ask me?
Click to expand...

No problem, and welcome to the forums, by the way. The word "loose" was in your thread title, although please don't let all this hassle over it give you an impression of the community. We're all very nice really. :D
 
In the title.
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Ah thanks! I was starting to think I needed glasses or something.. Typo indeed..

zaney said:
No problem, and welcome to the forums, by the way. The word "loose" was in your thread title, although please don't let all this hassle over it give you an impression of the community. We're all very nice really. :D
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Thanks and no worries. Have been keeping an eye on this site for months now, as I wanted an MBP. Thanks to this site I bought one at exactly the right moment (new updated model and last but not least, money on my account :D)
 
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