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MBP Charging

S

Simon 5000

macrumors member
Original poster
Jun 24, 2009
37
0
When I use my MBP at my desk, I was wondering what is the correct routine I should follow with charging, I mean, should I charge it up to 100% and then let it drop to about 10% until I charge it back up again, or should I leave it charging at 100% and not take the cable out, maybe I should charge until 50% and let it drop? Just want to make sure I'm taking care of my battery since I am at my desk most of the time. Thanks.

I own a June 09' MBP 15''
 
Leaving it plugged in is fine and will not hurt the battery
In general, you should fully discharge the battery once a month

Battery Care

Battery Calibration

Maximize Battery Charge

Woof, Woof - Dawg
pawprint.gif
 
MacDawg said:
Leaving it plugged in is fine and will not hurt the battery
In general, you should fully discharge the battery once a month

Battery Care

Battery Calibration

Maximize Battery Charge

Woof, Woof - Dawg
pawprint.gif
Click to expand...

Not to accuse, MacDawg, for you are most likely correct, but doesn't leaving it plugged in kill the battery? (OP, don't listen to this. I'm asking a question that's probably untrue. Listen to Dawg). I just need verification because what I've heard is a little different.:confused:
 
airplaneman said:
Not to accuse, MacDawg, for you are most likely correct, but doesn't leaving it plugged in kill the battery? (OP, don't listen to this. I'm asking a question that's probably untrue. Listen to Dawg). I just need verification because what I've heard is a little different.:confused:
Click to expand...

While the "official" position in the links above says Apple does not recommend leaving it plugged in all the time, you will find that users have done so with no ill effects on their battery life. Many use it as a desktop replacement.

The more important (in my opinion) recommendation from Apple is to discharge it once a month to maintain it.

Others can weigh in on this if they like

Woof, Woof - Dawg
pawprint.gif
 
MacDawg said:
While the "official" position in the links above says Apple does not recommend leaving it plugged in all the time, you will find that users have done so with no ill effects on their battery life. Many use it as a desktop replacement.

The more important (in my opinion) recommendation from Apple is to discharge it once a month to maintain it.

Others can weigh in on this if they like

Woof, Woof - Dawg
pawprint.gif
Click to expand...

Oh, I see.
 
Funny, I called apple about this exact question about a week ago.

The apple customer service rep told me that leaving it plugged in at 100 percent charge for extended periods of time is not dangerous to the battery like it used to be. Leaving batteries plugged in and charging used to create erosion in the battery because of the excessive heat it created. With the improvement of battery technology (read: lithium-polymer), as well as an improved system of charge management in apple's hardware for the new MBs and MBPs, this is not an issue like before. When the battery is at 99-100 percent charge, the light on your AC adapter turns from amber to green. This indicates that the charging is basically stopped and the computer is running mostly AC power. The battery has to be used in small amounts, because if the AC is suddenly unplugged and the battery has to go from 0 to 100 percent power, a power surge would happen and the computer's internals would fry.

But to make a long story short, apple engineers took the old laptop battery technology in to consideration and aimed to make a product that improves the experience of the general consumer. So leaving it plugged in will not affect battery longevity. It is advised though, with any battery, to discharge it fully once a month.

Side note: If you plan on leaving your laptop shut down for an extended period of time (a week or more), lithium-ion batteries are best stored at 40% charge.
 
The battery has to be used in small amounts, because if the AC is suddenly unplugged and the battery has to go from 0 to 100 percent power, a power surge would happen and the computer's internals would fry.
Click to expand...

So much for the "improved system of charge management." The quoted passage is just wrong, btw.
 
Read it:

"...if the AC is suddenly unplugged and the battery has to go from 0 to 100 percent power, a power surge would happen and the computer's internals would fry."

First of all your computer is never plugged directly into AC to begin with. Second, the battery goes from 0-100% power every time you unplug the power cord. I don't know about you, but my computer's internals seem to be functioning just fine.
 
miles01110 said:
Read it:

"...if the AC is suddenly unplugged and the battery has to go from 0 to 100 percent power, a power surge would happen and the computer's internals would fry."

First of all your computer is never plugged directly into AC in the first place. Second, the battery goes from 0-100% power every time you unplug the power cord. I don't know about you, but my computer's internals seem to be functioning just fine.
Click to expand...

But the bottom line is it doesn't ruin the battery life, right? I want my new MBP to last a while and I can't go about wasting battery...
 
Leaving it plugged in at 100% will not harm the battery. The only thing you can do that will harm the battery would be to charge it half way, unplug it for an hour plug it back in, unplug it, plug it back in, etc. (for short periods of time)
I always try to run it down completely once it's unplugged ( a few minutes doesn't matter) but what I described will run your battery down very quickly.
 
rick3000 said:
Leaving it plugged in at 100% will not harm the battery. The only thing you can do that will harm the battery would be to charge it half way, unplug it for an hour plug it back in, unplug it, plug it back in, etc. (for short periods of time)
I always try to run it down completely once it's unplugged ( a few minutes doesn't matter) but what I described will run your battery down very quickly.
Click to expand...

Actually that is probably better for the battery than leaving it plugged in all the time.
 
rick3000 said:
Leaving it plugged in at 100% will not harm the battery. The only thing you can do that will harm the battery would be to charge it half way, unplug it for an hour plug it back in, unplug it, plug it back in, etc. (for short periods of time)
I always try to run it down completely once it's unplugged ( a few minutes doesn't matter) but what I described will run your battery down very quickly.
Click to expand...

cababah said:
Actually that is probably better for the battery than leaving it plugged in all the time.
Click to expand...

rick3000 said:
Then go ahead and plug/unplug a lot over a short period of time. I have first hand experience with this.
Click to expand...

MacDawg said:
Uh... no

Woof, Woof - Dawg
pawprint.gif
Click to expand...

Oh dear, I'm confuzzled:confused:. So only if it is 100% do I plug it in, otherwise the battery will lose its health:confused:?
 
airplaneman said:
Oh dear, I'm confuzzled:confused:. So only if it is 100% do I plug it in, otherwise the battery will lose its health:confused:?
Click to expand...

It is OK to leave it plugged in all the time
Make sure you run it down at least once per month

Avoid repeatedly plugging it and unplugging it for short periods of time

Woof, Woof - Dawg
pawprint.gif
 
I don't know wheter it hurts or not the battery but when I have the mid09 mbp13" plugged for a week (12h/day maybe less), the battery indicator says It's charged at 95-96%.

It is like every 12 plugged hours 1% of the battery goes away. Like I've said I don't know wheter it could be real or just a misscalibration, but the first time I saw it I get quite annoyed.

Anyway, have to say that when discharging and charging again, I can reach again the 100%.
 
Just use the computer in a manner that suits you best..especially if you have Apple Care.

It isn't worth it being anal about something that really has no significant impact.
 
For one of my 15", after 2 years of heavy use, always plugged into the charger with battery in... Had 20 cycles on the battery, with about a 250mah capacity!

Apple replaced it at no charge :apple:


I know to take out the battery for now on, if its gonna be plugged in at all times!
 
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