[gregfripp]

I am intending to buy a new macbook pro with the latest batteries.
But I use it as a home based machine.
I would expect it to be normally connected to the mains.
Will that be good or bad for these new batteries?
How should I use/charge these?
Your help/advice appreciated.
Greg

[Big Mac]

See this thread

[gregfripp]

Thanks for suggesting that thread, but it concerns lithium something( -not-polymer) batteries.
I need to know what existing 17{" macbook pro users do with their NEW lithium polymer
batteries when used in a normal desk (plugged in) type situation.
Do they just let them discharge themselves, and then recharge?
Using up a charge cycle?
Or is there a better way?
Hopefully,
Greg

[kylef]

The best way to keep battery life is to run it up to 100%, and then don't charge it until you have about 5 minutes left on that charge.

[gregfripp]

Sorry I also forgot to mention
what is the replacement cost of these new ones?
Greg

[Simon]

Originally Posted by kylef 

The best way to keep battery life is to run it up to 100%, and then don't charge it until you have about 5 minutes left on that charge.

That would mean essentially constantly cycling the battery. I'm pretty sure that's not what you want to do.

[SpaceMonkey]

Originally Posted by gregfripp 

Sorry I also forgot to mention
what is the replacement cost of these new ones?
Greg

It's on their website here: Apple - Support - Replacing the Battery in your MacBook Pro (2009 models with built-in batteries)

[gregfripp]

Originally Posted by SpaceMonkey 

It's on their website here: Apple - Support - Replacing the Battery in your MacBook Pro (2009 models with built-in batteries)

thanks for answering that part of my questions
Greg

[mduell]

Keep it plugged in all the time. Run it through one net cycle (could be two half cycles, 70% discharge and 30% discharge, or whatever) a month.

[CharlesS]

Originally Posted by kylef 

The best way to keep battery life is to run it up to 100%, and then don't charge it until you have about 5 minutes left on that charge.

No, don't do this. These instructions are appropriate for a NiCd or NiMH battery, but will cause a decrease in overall battery life if you do it with a Li-Ion or Li-Po battery, such as the ones in pretty much all laptops made after 1996.

[gregfripp]

Thank you all for your (confusing) answers.
It seems that none of you really can give me full information, and that only Apple can.
Who/where do I ask?
Greg

[Wiskedjak]

The best answer is that there is no best answer. Regard laptop batteries, there is a lot of misinformation out there, most notably from those who make money off of batteries. What they won't tell you is that current laptop batteries start to experience a drop in capacity after a certain number of charge cycles, but they won't tell you *how many* charge cycles though the rule of thumb is about after a year of regular use.

I bought my MacBook about 2.5 years ago, use it *a lot* and I currently get about 20 minutes out of it's original battery. (incidentally, the Toshiba Tecra I bought over 10 years ago still gets about 30 minutes out of it's original battery)

[ghporter]

Don't leave it plugged in all the time. Don't constantly cycle the battery from full to empty. Don't run the battery down to where the computer shuts itself down except rarely (like when it needs to be calibrated).

In other words, the BEST thing to do is to act like the battery is a finite resource and treat it gently. Authoritative? Maybe not. But this advice should maximize your ability to use the battery.

By the way, I've followed these guidelines on my late-2006 MBP, and the battery still has something over 90% of its rated capacity. So empirically it does work.

[kylef]

Looking at it from a different perspective, yes you're probably right to not cycle it 100%. But occasional cycles are important to maintain full functionaility (neologism ftw)

[JKT]

Go to the source to end your confusion:

Apple - Batteries - Notebooks

[JKT]

Also, an invaluable piece of freeware for any laptop owner:

coconut-flavour.com - [coconutBattery 2.6.5]

[JKT]

Originally Posted by Wiskedjak 

What they won't tell you is that current laptop batteries start to experience a drop in capacity after a certain number of charge cycles, but they won't tell you *how many* charge cycles though the rule of thumb is about after a year of regular use.

Um, yes they will: around 300 full charge cycles for a standard Li battery will leave you with approx. 80% of its original capacity. From that point on, it'll start losing charge capacity much more quickly.

Edit: Apple are claiming about 1000 charge cycles for their newest built-in battery design, fwiw.

[mduell]

Originally Posted by JKT 

Um, yes they will: around 300 full charge cycles for a standard Li battery will leave you with approx. 80% of its original capacity. From that point on, it'll start losing charge capacity much more quickly.

Marketing BS. Three people (poor sample size) in my office are down to half battery life after 100 cycles and 1 year.

[JKT]

Then you have a strong claim for faulty batteries don't you.

[Simon]

Apple will replace every battery that is
a) within its first 12 months (AC doesn't count)
b) has less than 300 cycles
c) has less than 80% of its original capacity
d) shows no signs of physical damage

So anybody with such a battery just needs to make one phone call. Problem solved. And everybody lived happily ever after.

[Wiskedjak]

Originally Posted by Simon 

Apple will replace every battery that is
a) within its first 12 months (AC doesn't count)
b) has less than 300 cycles
c) has less than 80% of its original capacity
d) shows no signs of physical damage

So anybody with such a battery just needs to make one phone call. Problem solved. And everybody lived happily ever after.

They wouldn't replace mine that matched that description.

[Simon]

Why not? Did you go to a store or did you call them? I've never had any problems when I called them.

[TribeLeader]

Originally Posted by JKT 

Go to the source to end your confusion:

Apple - Batteries - Notebooks

Thanks for the link. That will be helpful to me when I get my new Mac (my second ever) in a few weeks.

I've had my first Mac (a G4 PB), including the battery, for nearly 6 years. I've never really used the battery very much. According to the iStat Pro widget, I've had 62 cycles, and my battery health is down to 31% (down from 36% when I let the battery drain today for the first time in awhile).

Anyway, I'll try to do it better on my next one.

[Wiskedjak]

Originally Posted by TribeLeader 

Thanks for the link. That will be helpful to me when I get my new Mac (my second ever) in a few weeks.

I've had my first Mac (a G4 PB), including the battery, for nearly 6 years. I've never really used the battery very much. According to the iStat Pro widget, I've had 62 cycles, and my battery health is down to 31% (down from 36% when I let the battery drain today for the first time in awhile).

Anyway, I'll try to do it better on my next one.

62 cycles over 6 years? sounds like you barely use that laptop.

[TribeLeader]

Originally Posted by Wiskedjak 

62 cycles over 6 years? sounds like you barely use that laptop.

That's according to iStat, of course.

Actually, I use it heavily. It's just virtually always plugged in.

[discostu665]

mduell,

All those batteries sound defective. I've never had a battery reach 50% health before 4 years.

Anyways, my situation is at the opposite end of the spectrum. I'm pretty sure coconut battery is reading this wrong, but after 437 cycles and two years, my battery still at 99% capacity.

[Simon]

How to diagnose:
1) Open System Profiler > Hardware > Power
2) Read Full charge capacity (mAh) value

Compare that value to a new battery. On the pre-UB MB that's ~5600 mAh, on the pre-UB MB it's ~5000 mAh.

If the value you got is less than 80% of the original full charge capacity and you are below 300 cycles, you are eligible for free replacement if the battery is less than 12 months old. There's no need for any apps like Coconut Battery with their "health indication". The only thing that counts to Apple are those three pieces of information you get form Sys Profiler and the proof of purchase.

People will notice that when they go below 80% and are within 300 cycles the status given by Sys Profiler > Hardware > Power > Health Information > Condition will go from 'Good' to 'Check Battery'. It's usually a good idea to calibrate the battery first and confirm the numbers again. Then you call Apple.

In fact, that's what I'm doing right now for a MBP of mine. It has lost 30% within six months and 67 cycles. Clearly a lemon. I called Apple, gave them the information, and without further ado they sent a replacement (scheduled to arrive on Monday). Just like they always do.

[Simon]

Originally Posted by discostu665 

All those batteries sound defective. I've never had a battery reach 50% health before 4 years.

That's right. 50% in 100 cycles and a year means they are defective. A simple call to Apple would have been enough to solve the problem.

Of course once you're past that one year you have lost entitlement to a free replacement. IOW when your battery has reached about 11 months make sure to check it's ok. If it's bad and you don't notice till later you'll be paying.

[Simon]

Originally Posted by discostu665 

Anyways, my situation is at the opposite end of the spectrum. I'm pretty sure coconut battery is reading this wrong, but after 437 cycles and two years, my battery still at 99% capacity.

Forget about what Coconut Battery says. After 437 cycles what is your full charge capacity in mAh according to System Profiler?

[Simon]

Originally Posted by Wiskedjak 

62 cycles over 6 years? sounds like you barely use that laptop.

Originally Posted by TribeLeader 

That's according to iStat, of course.
Actually, I use it heavily. It's just virtually always plugged in.

Nothing wrong with iStat there. One cycle is reached after charging/discharging corresponding to 100% capacity. If you never unplug your Mac you could end up with basically zero cycles after several years.

A cycle is a measure of battery usage, not age. Apple knows how long you've had the battery. They want to be able to gauge how heavily it was being used in that time.

[JKT]

Originally Posted by Simon 

Forget about what Coconut Battery says. After 437 cycles what is your full charge capacity in mAh according to System Profiler?

I would guess that it is going to be the same thing as Coconut Battery is just an UI to the same information as is displayed in System Profiler.

(Btw, its utility for me is that you can easily keep a record of your values over time to see if your battery is degrading rapidly or not).

[JKT]

Originally Posted by Simon 

Nothing wrong with iStat there. One cycle is reached after charging/discharging corresponding to 100% capacity. If you never unplug your Mac you could end up with basically zero cycles after several years.

A cycle is a measure of battery usage, not age. App;e knows how long you've had the battery. They want to be able to gauge how heavily it was being used in that time.

Fwiw, Apple's recommendations for this situation (where you do use your laptop on the mains like this the vast majority of the time) are that you should perform a full discharge/charge cycle once per month. I started doing this after about 7 months of owning my Powerbook and it is still at 75% capacity after approx. 5 years and 3 months since its production.

[Wiskedjak]

Apple really should build their battery use recommendations into the OS rather than bury them on some tech support page that very few will read. It wouldn't be difficult at all for the system to say "It looks like you're charging your laptop more than you need to. To make your battery last longer, we recommend ... "

[ghporter]

Originally Posted by Wiskedjak 

Apple really should build their battery use recommendations into the OS rather than bury them on some tech support page that very few will read. It wouldn't be difficult at all for the system to say "It looks like you're charging your laptop more than you need to. To make your battery last longer, we recommend ... "

That sounds like the silly hand holding Windows provides-only on an actually functional subject. Frankly, isn't the use of the computer the user's responsibility? If the user is curious about how to maximize battery life (rather than battery run time, which seems to be what most notebook users are more concerned about), then the user is probably also smart enough to use that "Internet" thing to look it up. Sarcasm aside, your suggestion is way too nanny-like for most users. "It's bad enough they make me use their file system, now I have to unplug the computer because they say it'll make the battery last longer? <roll eyes WAY back> Come ON!" They'd get way more complaints about that than issues with batteries dieing early.

[Simon]

Originally Posted by JKT 

I would guess that it is going to be the same thing as Coconut Battery is just an UI to the same information as is displayed in System Profiler. .

Not entirely. Here's the deal. The full charge capacity CB reads back is of course the same as what Sys Profiler tells you. But then CB gives people a percentage as some kind of indicator of battery health. And that's where it goes beyond reading back system parameters. If the CB people got the original full charge capacity estimate wrong the app will give people false information about the state of their battery.

In this case that's exactly what I suspect happened. That's why I'm asking what that battery's full charge capacity is after 437 cycles and two years rather than relying on CB's bogus 99% figure.

[CharlesS]

Originally Posted by Wiskedjak 

Apple really should build their battery use recommendations into the OS rather than bury them on some tech support page that very few will read. It wouldn't be difficult at all for the system to say "It looks like you're charging your laptop more than you need to. To make your battery last longer, we recommend ... "

The "discharge once a month" recommendation isn't to make the battery last longer, it's to keep the battery readout calibrated. The lithium-polymer batteries that the MBPs use are fine with being kept mostly charged, but charging a battery from almost empty will allow the computer to figure out how much energy the battery will hold. If you don't do this, the only negative effect will be that the battery readout may not be completely accurate in telling you how much time left you have on the battery, you might get inaccurate information when checking on the battery's health, etc., which is kind of annoying but not mission-critical, and unless you leave your computer hooked up to AC power every time you use it, chances are you'll probably end up running the battery down every once in a while anyway.

[JKT]

Originally Posted by Simon 

Not entirely. Here's the deal. The full charge capacity CB reads back is of course the same as what Sys Profiler tells you. But then CB gives people a percentage as some kind of indicator of battery health. And that's where it goes beyond reading back system parameters. If the CB people got the original full charge capacity estimate wrong the app will give people false information about the state of their battery.

In this case that's exactly what I suspect happened. That's why I'm asking what that battery's full charge capacity is after 437 cycles and two years rather than relying on CB's bogus 99% figure.

My understanding is that it is just getting the values from ioreg which is the same as how System Profiler obtains them, which on a relatively recent Mac will also include the original capacity of the battery. E.g.:

Code:
$ ioreg -l | grep Capacity
    | | |   "IOBatteryInfo" = ({"Capacity"=3971,"Amperage"=0,
            "Cycle Count"=43,"Current"=3962,"Voltage"=12493,
            "Flags"=838860805,"AbsoluteMaxCapacity"=4200})
    | |   |   |     "IOBatteryInfo" = ({"Capacity"=3971,
                    "Amperage"=0,"Cycle Count"=43,"Current"=3962,
                    "Voltage"=12493,"Flags"=838860805,
                    "AbsoluteMaxCapacity"=4200})

However, your point is certainly valid - it is the mAh values that are important (which Coconut battery does provide at the same time, btw).

[JKT]

Originally Posted by CharlesS 

The "discharge once a month" recommendation isn't to make the battery last longer, it's to keep the battery readout calibrated. <snip>

That isn't the way Apple describe it:

Standard Maintenance
For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month. Need a reminder? Add an event to your desktop’s iCal.

[mduell]

Originally Posted by Simon 

Apple will replace every battery that is
a) within its first 12 months (AC doesn't count)
b) has less than 300 cycles
c) has less than 80% of its original capacity
d) shows no signs of physical damage

So anybody with such a battery just needs to make one phone call. Problem solved. And everybody lived happily ever after.

Originally Posted by Simon 

That's right. 50% in 100 cycles and a year means they are defective. A simple call to Apple would have been enough to solve the problem.

Of course once you're past that one year you have lost entitlement to a free replacement. IOW when your battery has reached about 11 months make sure to check it's ok. If it's bad and you don't notice till later you'll be paying.

Cycle count: 93
Serial number indicates manufactured 2008 week 11 (March); was a stock model we purchased in approximately May.
Full charge capacity (mAh): 2914 [5556 mAh original => 52%]
So a hundred cycles, a year, half battery life, but no replacement eligibility from Apple.

It's our fault for not checking battery capacity on the 364th day. But the batteries are coming up well short of Apple's marketing claims.

[Simon]

Originally Posted by mduell 

It's our fault for not checking battery capacity on the 364th day.

Exactly.

[ghporter]

Originally Posted by CharlesS 

The "discharge once a month" recommendation isn't to make the battery last longer, it's to keep the battery readout calibrated. The lithium-polymer batteries that the MBPs use are fine with being kept mostly charged, but charging a battery from almost empty will allow the computer to figure out how much energy the battery will hold. If you don't do this, the only negative effect will be that the battery readout may not be completely accurate in telling you how much time left you have on the battery, you might get inaccurate information when checking on the battery's health, etc., which is kind of annoying but not mission-critical, and unless you leave your computer hooked up to AC power every time you use it, chances are you'll probably end up running the battery down every once in a while anyway.

Originally Posted by JKT 

That isn't the way Apple describe it:

Standard Maintenance
For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month. Need a reminder? Add an event to your desktop’s iCal.

JKT, you really didn't contradict CharlesS' post at all. He didn't go in to detail, but his last sentence and specifically the clause: "unless you leave your computer hooked up to AC power every time you use it," shows that he meant pretty much exactly what Apple says in your quote. He WAS saying where the "monthly drain the battery" bit came from. I don't really care if my remaining capacity display is off by 10 minutes because I almost always have my power supply with me and seldom use my MBP anywhere I can't find an outlet to use.

I repeat my previous battery rules:

Originally Posted by ghporter

Don't leave it plugged in all the time. Don't constantly cycle the battery from full to empty. Don't run the battery down to where the computer shuts itself down except rarely (like when it needs to be calibrated).

These simple rules handle the vast majority of usage situations, and are simple ways to keep your battery as healthy as possible while still using the computer like the notebook it is.

[Wiskedjak]

Originally Posted by ghporter 

That sounds like the silly hand holding Windows provides-only on an actually functional subject. Frankly, isn't the use of the computer the user's responsibility? If the user is curious about how to maximize battery life (rather than battery run time, which seems to be what most notebook users are more concerned about), then the user is probably also smart enough to use that "Internet" thing to look it up. Sarcasm aside, your suggestion is way too nanny-like for most users. "It's bad enough they make me use their file system, now I have to unplug the computer because they say it'll make the battery last longer? <roll eyes WAY back> Come ON!" They'd get way more complaints about that than issues with batteries dieing early.

Perhaps, but there's so much mystique and misinformation regarding battery care that it's difficult to know who to believe in the course of a web-search. One only has to look as far as this thread to see a variety of understandings on maximizing laptop battery life. I wouldn't mind my OS making battery usage recommendations that might save me a few hundred dollars over the life of my laptop, especially since the MacOS is intended to be easily used by less savvy users and if such a service were easily disabled.

[ghporter]

Originally Posted by Wiskedjak 

Perhaps, but there's so much mystique and misinformation regarding battery care that it's difficult to know who to believe in the course of a web-search. One only has to look as far as this thread to see a variety of understandings on maximizing laptop battery life. I wouldn't mind my OS making battery usage recommendations that might save me a few hundred dollars over the life of my laptop, especially since the MacOS is intended to be easily used by less savvy users and if such a service were easily disabled.

Going to Apple's knowledge base shouldn't be the "web search challenge" that is seems to be for some people. From Apple's support site, just typing "battery" in the search box gets you to the Apple battery page, which provides links for battery support for notebooks, iPods and iPhones. My biggest question about having problems getting "good information" would be "why don't you just ask Apple." But it does seem that some rather smart people just don't think of this for some reason...

I don't dispute that battery management advice would be helpful-not at all! I think it would be a challenge for Apple to find a good "middle ground" between "hands off" and "mother hen," but the potential for ticking off customers seems kind of high.

[discostu665]

Originally Posted by Simon 

Forget about what Coconut Battery says. After 437 cycles what is your full charge capacity in mAh according to System Profiler?

Simon,
For my white macbook, 2 years old (original battery):

Charge Information:
Charge remaining (mAh): 5241
Fully charged: Yes
Charging: No
Full charge capacity (mAh): 5243
Health Information:
Cycle count: 437
Condition: Good
Battery Installed: Yes

I think there must be an error...

[Simon]

The interesting thing here is that your full charge capacity is 5243 mAh which is more than a MB battery usually comes with (that would be about ~5Ah, but it can be as much as 5.1 in some cases).

How much battery time do you get?

[discostu665]

With just safari, word, and system profiler on, and the display on the lowest brightness setting, the battery meter bounces between 4:50 to 5:46 with 99% left. I've never paid attention to see if it's correct.

[Simon]

Forget about the indicator. If your battery is fubar or the calibration is bad that reading will be just as misleading.

What I'm asking is how long you can actually run off of one charge? 1 hour or 4 hours?