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When the battery on my Macbook Pro is fully charged, should i unplug the power cord?

I know my $2800 (at the time) Dell M1710 XPS laptop that was purchased in 2006 -- stayed plugged in 98% of the time and its battery was dead within a year.

With my MBP, it's plugged in most of the time also, but I'm adhering to the once a month calibration just to make sure. I'm sure the build quality on the MBP is better than that of my Dell XPS, but the XPS in back 2006 was a top of the line gaming PC and its battery was lifeless in a year. Dell wouldn't cover it because it was just outside the 1 yr warranty on batteries. I still wonder that if I let it drain to empty then recharged more often like I do now w/the MBP, if it would've extended the life of the battery.
 
My experience, I have a Late 2008 MBP with removable battery. Purchased in Feb. 2009 and used mostly plugged in constantly (unplugging to go to and from work) until September or so, and then the battery reported problems. Took it to a Genius to replace and they did so without question.

I suggest charging it fully and discharging it fully as often as possible.
 
tekchic said:
I know my $2800 (at the time) Dell M1710 XPS laptop that was purchased in 2006 -- stayed plugged in 98% of the time and its battery was dead within a year.
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If you follow the link I provided in post #2 in this thread, you would read:
GGJstudios said:
A/C POWER
Apple does not recommend leaving your portable plugged in all the time.
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AppleCare support recommends that if you leave your Mac plugged in most of the time, unplug it every 2 or 3 days and run on battery down to somewhere around 50%, then plug it back in. That keeps the electrons moving.

As long as you're running it on battery at least every few days and calibrate every month or two, you'll be fine.
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Some good posts on here, cheers guys.

I don't understand about the whole battery warranty deal, if it dies it will effect functionality (same effect as having the battery removed, yes?), plus it's not user replaceable, imagine if they did the same for RAM, HDD etc.
 
runebinder said:
Some good posts on here, cheers guys.

I don't understand about the whole battery warranty deal, if it dies it will effect functionality (same effect as having the battery removed, yes?), plus it's not user replaceable, imagine if they did the same for RAM, HDD etc.
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Read the link in post #2. That will answer a LOT of your questions.
 
Thanks for the tip. I didn't know about it in 2006. :p

I actually take the MBP to bed several nights a week to code extra late, so I think I'm keeping the electrons flowing pretty well now. :)
 
Thanks for the info guys... very helpful indeed.

I frequently run my MBP on battery and so the cycles are clocking up but today I charged it fully from about 80% but this didn't add to the cycle count.
So my question (and without starting a new thread) is when fully charging, at roughly what initial % charge does the battery have to be to constitute a 'cycle'?
 
bigjobby said:
Thanks for the info guys... very helpful indeed.

I frequently run my MBP on battery and so the cycles are clocking up but today I charged it fully from about 80% but this didn't add to the cycle count.
So my question (and without starting a new thread) is when fully charging, at roughly what initial % charge does the battery have to be to constitute a 'cycle'?
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This is getting redundant. Read the link in post #2, paying attention to the section called, WHAT IS A CYCLE?
 
GGJstudios said:
If you read the information in the link I provided in the 2nd post in this thread, you would know that your statement is not correct.

From: MacBook and MacBook Pro: Mac reduces processor speed when battery is removed while operating from an A/C adaptor


I think you meant to say "only on AC power, with the battery removed". Other than that, your statements are correct.
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That is most likely a legal/safety/user precaution, not an actual usage limitation.

My old macbook pro ran without a battery for almost 2 months while fighting with warranties and failed chinese battery replacements, and even when using very cpu intensive programs, and gaming, I never had a single shut down or restart.

While it may be true the processor is tuned down without a battery, I really doubt any charge is regularly drawn from the battery during normal operation.

It's perfectly safe to leave the computer plugged in, and follow the recommended calibration procedure. My wife's macbook is almost 4 years old, has about 30 cycles on the battery (she leaves it near the couch and never takes it out of the house) and the battery health from coconut is like 98%
 
Guys!

If you have the laptop ON with the charger connected and you unplug the charger the laptop keep working. So youre always charging and draining.
Otherwise if the laptop is bypassing the battery it will turn OFF inmediatly.

:eek: ;)
 
iamrawr said:
Very helpful thank you. So is it still possible to overcharge a computer/device? If so, what happens to it?
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Overcharging a battery will just overheat it and damage its cells, thereby reducing charge capacity and reducing battery life.

But again, in this day and age, unless there are huge bold letters telling you not to leave it plugged in after being fully charged, then you have nothing to worry about.
 
paying 2000+ bucks for something should come with tons of quality. i would sure be pissed if something simple as leaving in a battery charger while the battery is filled as a possible way of damaging my mbp......
 
Not 100% sure what is being said here but here is my take:

If you have the battery and charger plugged in, you can disconnect it and it will still be working, but the battery will drain. But if the battery is being bypassed by the charger, disconnecting the charger will turn off the computer.

Which isn't right, but the 'eek' and 'wink' at the end of this is confusing.

But as I was misquoted above (what is up with that?), if you have a charger, use it.

djlutzker said:
If you have the laptop ON with the charger connected and you unplug the charger the laptop keep working. So youre always charging and draining.
Otherwise if the laptop is bypassing the battery it will turn OFF inmediatly.
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sammich said:
Not 100% sure what is being said here but here is my take:

If you have the battery and charger plugged in, you can disconnect it and it will still be working, but the battery will drain. But if the battery is being bypassed by the charger, disconnecting the charger will turn off the computer.

Which isn't right, but the 'eek' and 'wink' at the end of this is confusing.

But as I was misquoted above (what is up with that?), if you have a charger, use it.
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In my explanation I simplified things to make it easier to understand. All I said was that after the power cord enters the computer, the wiring splits into two, one to the battery and the other to the logic board. And yes, once the battery is fully charged, the power from the POWER CORD bypasses the battery and goes only to the logic board.

However, that's from the POWER CORD perspective. The BATTERY itself has its own connection to the logic board, which acts like a backup mode that's always in standby when the computer's on. Explaining further would get very technical and boring :p

But yeah, just take it from everyone, it's safe to leave the power cord plugged in all the time. And if you have your doubts, then DON'T leave it plugged in all the time. Simple as that.
 
just got my mbp 15 i5 yesterday and im scouring the boards for tips on the best way to use my expensive ass new toy...

so its clear that its safe to keep the laptop plugged in, but i think the better question that everyone wants to know is if its actually BETTER to have it plugged in all the time.

i was actually planning on charging it to 100% at home and leaving the charger at home and go on battery power only when i get to work, then charge it again when i get home kinda like a phone.


so again, is it actually better for the laptop and battery to leave it plugged in as much as possible???
 
mansanas said:
so again, is it actually better for the laptop and battery to leave it plugged in as much as possible???
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It's better in that the battery will go through fewer charge/discharge cycles, and so last longer.

Another thing for new MBP owners to be aware of is that if you unplug your MBP briefly and then plug it back in the battery will not start charging. It will only start to charge when the battery has 94% or less power.
 
Mark.W said:
This is the exact opposite of what a "genius" at the Apple Store told me. He said that even when the computer is plugged in and the battery is full, you are still running on battery power, which means that the battery is constantly draining and charging. In other words, there is no such thing as a "battery bypass" when the battery is full.

My personal experience with [admittedly non-apple] laptops seems to support this theory. I used to have a Sony Vaio which was basically a desktop replacement and was plugged in 98% of the time. A year later, the battery was pretty much worthless.
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I think the Genius just doesn't know. Maybe he's not a genius. What actually happens is that when the battery is full it will be turned off. You can see this actually because after a while the battery level will drop but very very slowly. After a few weeks you may only have 98-97% left - which is a normal discharge. As another poster said, once it reaches a certain level, it will recharge. That Sony Vaio (same happened to mine btw) probably killed its battery because it was constantly charging as soon as the battery was getting below 100% while the MBP only begins to charges when the battery is less (I thought it was 95% though). Overusing a battery is bad for a battery, it comes down to that. Excessively charging it, perhaps coupled in a hot notebook case, is also not good for the batteries. Just use them whenever you need them but don't use them when you can use a power socket. And once a month let them fully drain.
 
I think it is 94 or less percent. I have just unplugged my MBP from the power to check.

You were right and I was wrong, it will charge on 95%.
 
Tom71 said:
What actually happens is that when the battery is full it will be turned off.
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That's not true. The battery does not "turn off". When the battery is full, the MagSafe adapter will stop charging, but the battery is still in use. During periods of peak demand, your MBP can draw from both the AC adapter and the battery, which is why Apple recommends that you don't run on AC power without the battery. Under normal conditions, when running on AC power with a full battery, the battery is NOT being used and will not fall below its fully charged state, as long as the Mac is running on AC power.
 
GGJstudios said:
That's not true. The battery does not "turn off". When the battery is full, the MagSafe adapter will stop charging, but the battery is still in use. During periods of peak demand, your MBP can draw from both the AC adapter and the battery, which is why Apple recommends that you don't run on AC power without the battery. Under normal conditions, when running on AC power with a full battery, the battery is NOT being used and will not fall below its fully charged state, as long as the Mac is running on AC power.
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A little bit pedantic, are we. It is basically turned off in terms that it will not be charged and not used. If the MBP draws more power than the adaptor can handle it may be temporarily switched on to support the adaptor. Which in fact is a cool thing to do.
 
I used my late 2007 MacBook 95% of the time plugged, using it on battery once a week or every 15 days. I also calibrated it every 60 days.

26 months later it was on 118 cycles and 96% battery health.
 
USE YOUR BATTERY

Now that I have your attention...you can leave your MBP plugged in after charging, and I recommend it. But if this is going to be a laptop that doesn't leave your desk (aka a desktop), you're going to be in trouble. If you charge Li-Ion batteries and don't use them, you'll ruin them. Every couple days, take it off the charger and run it for a while; you don't have to do a full discharge cycle every time, just get the juices flowing.

A lot of people will tell you its alright to leave it plugged in all the time, and that with the technology these days, its all ok. Li-Ion batteries are still Li-Ion batteries, and if you don't use them, the degrade. Sure, they don't have the crystallization problems of the NiCd batteries did, but there is still degradation.

We're lucky having MBPs, since Apple's new battery tech is very smart. The battery has 8 cells or so, and the laptop draws from 1 cell at a time, until its near depletion, and it switches to another, rather than drawing a little from every cell. The battery as a whole lasts longer, as there are less partial charges. In addition, the built-in circuitry counts the charge cycles of each cell, and chooses the the cell with the least charge cycles on it, and draws power from it first. Its really ingenious.

But anyway. Use the battery, or lose the battery. Its not worth even the possibility of ruining the battery when you can easily prevent all of this by pulling 1 cord, twice a week
 
Tom71 said:
A little bit pedantic, are we. It is basically turned off in terms that it will not be charged and not used. If the MBP draws more power than the adaptor can handle it may be temporarily switched on to support the adaptor. Which in fact is a cool thing to do.
Click to expand...
Not pedantic; just accurate. There IS no on/off switch, physically or logically, on MBP batteries. It does NOT switch off and on.
 
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