Is it ok if I do this?

Stinkythe1

macrumors regular
Original poster
Mar 30, 2005
208
0
I have a 12" powerbook and it is plugged in most of the time, although I occasionally unplug it and run around the house with it until it gets to about 25-30%. Anyway, at night, I would leave it plugged in overnight, but the blue glow from the power connector is really bright, so I unplug it. However, the next morning when I plug it back in, I notice that the battery goes down to about 95% and begins charging again.

Does it hurt the battery if I do this every night?
 

alex_ant

macrumors 68020
Feb 5, 2002
2,473
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All up in your bidness
Li-Ion has a finite number of charge cycles and the life goes down a little bit (probably roughly 30 seconds, would be my estimate) with every charge. The more you discharge it (the lower the % you bring it down to) the more severe this effect will be. The only way to preserve the battery is to never use it.

Then again, what's the point of a laptop if you never use the battery. The idea is to find a balance between convenience & battery longevity that works for you.

If you are annoyed by the blue glow, maybe cover it up with a dark piece of paper or put electrical tape over the light. Try to unplug the thing only when necessary.
 

michaelrjohnson

macrumors 68020
Aug 9, 2000
2,174
1
53132
However, it's very important to discharge the battery *completely* every once in awhile to maintain good battery health. It's not good to leave it plugged in *all* the time or to never let it discharge.
 

7on

macrumors 601
Nov 9, 2003
4,940
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Dress Rosa
michaelrjohnson said:
However, it's very important to discharge the battery *completely* every once in awhile to maintain good battery health. It's not good to leave it plugged in *all* the time or to never let it discharge.
lol, this is not so much the case anymore where draining it completely can in fact be more harmful to the battery. I leave my Pod plugged in all the time and still get 9 hours after 2 years.

Come to think about it you can't drain laptop batteries completely, since they go to sleep @ around 5%. And waiting for it to waste that 5% might as well take up a day and also will drain the internal backup battery. Try it, put your PB to sleep and pop out the battery - your pb should still be sleeping. I do not know if this battery is rechargeable either since I have heard reports of some people not being able to do this with their powerbooks.
 

Eniregnat

macrumors 68000
Jan 22, 2003
1,842
0
In your head.
7on said:
lol, this is not so much the case anymore where draining it completely can in fact be more harmful to the battery. I leave my Pod plugged in all the time and still get 9 hours after 2 years.

Come to think about it you can't drain laptop batteries completely, since they go to sleep @ around 5%. And waiting for it to waste that 5% might as well take up a day and also will drain the internal backup battery. Try it, put your PB to sleep and pop out the battery - your pb should still be sleeping. I do not know if this battery is rechargeable either since I have heard reports of some people not being able to do this with their PowerBooks.
Read Apple's Article on laptop batteries- They update it from time to time.

All batteries have a finite number of times that they can be charged. It is nearly impossible to truly completely discharge the batteries on Apple's laptops, as they are "smart" and have a real "memory". The processor inside the battery keeps track on heat, voltage and amperage in and out, load, etc... It keeps track of each full cycle, that is, if you charge and discharge your iBook 25% of the way 4 times, that's 1 full cycle.

Look here for information about your battery: Finder-->About This Mac-->More Info button->Content->Hardware>Power.
Here you will see the full charging capacity (this will decrease slowly through time), current charge (this will change as you discharge the battery) and the cycle count.

To me, good battery practice is this. I am very mobile and can't/won't plug in when ever it is possible (an etiquette thing). I have two batteries- one that I charge discharge as needed, the second, I only completely cycle (discharge and then full uninterrupted charge.) Both batteries get a complete cycle once a month, needed or not.

Discharging your battery by running the computer until it is forced to sleep is good practice (read Apple's article) Doing this and then forgetting about the battery for a while and not charging it is bad practice. This will completely discharge the battery, beyond what its firmware can protect it from. This should significantly degrade the battery.

You might just think about shutting down the compuer, as the boot time on Mac's is so quick.
 

Stinkythe1

macrumors regular
Original poster
Mar 30, 2005
208
0
That's great and all, but my question is, does it hurt it to keep draining the battery by 5% and then charging it back up every day? Or should I leave it plugged in overnight and put a peice of paper over it?
 

Applespider

macrumors G4
Stinkythe1 said:
That's great and all, but my question is, does it hurt it to keep draining the battery by 5% and then charging it back up every day? Or should I leave it plugged in overnight and put a peice of paper over it?
Probably a little, yes. You'd be better off using it down to 50% or so before you plug it in. Or even better, get that piece of black paper and put it over the light.
 

Eniregnat

macrumors 68000
Jan 22, 2003
1,842
0
In your head.
You should be fine. There are thoes that worry about takeing their car out of the garage because it adds wear and tear. You should be fine. - still read Apple's article.
 

mduser63

macrumors 68040
Nov 9, 2004
3,038
30
Salt Lake City, UT
7on said:
Try it, put your PB to sleep and pop out the battery - your pb should still be sleeping. I do not know if this battery is rechargeable either since I have heard reports of some people not being able to do this with their powerbooks.
15" and 17" PowerBooks have this capability, the 12" PB doesn't. Just one of the little features that the 12" PB is lacking compared to the bigger PBs. If you want to switch batteries on the 12", you have to either plug it in, or shut it down first.