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TMO Quick Tip - Calibrating Your Laptop Battery

by , 7:30 AM EDT, May 12th, 2006

When you buy a brand new PowerBook, iBook, or MacBook Pro, it comes with a fresh battery ready to be charged. If you don't properly calibrate your battery, however, you won't get the maximum run time that it offers. Apple and many third party batteries include a built-in microprocessor that tracks the battery charge. Until you run your new battery through the calibration process, the microprocessor has to guess how much of a charge it can actually hold.

Here's how to calibrate your battery:
PowerBook G4 and iBook

  • Fully charge your battery. If your power adapter light is green instead of orange, and the charge indicator lights on the battery are off, your battery is completely charged.
  • Disconnect the power adapter and use your 'Book until the battery is drained and your computer goes into its forced sleep mode. I usually play a DVD on my PowerBook to drain the battery.
  • Reconnect the power adapter and fully charge your battery again.

15-inch PowerBook G4 (Double-layer SuperDrive) and MacBook Pro

  • Fully charge your battery. If your power adapter light is green, and the menu bar battery indicator shows a full charge, your battery is fully charged.
  • Run your 'Book for at least two more hours with the power adapter connected.
  • Disconnect the power adapter and use your laptop until it goes into forced sleep mode.
  • Let your laptop sleep for at least five hours.
  • Reconnect the power adapter and let your 'Book fully charge again.

A properly calibrated battery will have a longer life span and give you more usable time between charges. Be sure to calibrate your battery when you buy a new Mac, and also if you purchase one new.

if you have ideas for Mac related tips that you think other TMO readers might find helpful.

Observer Comments

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Close Name:Guest
Fri May 12, 2006 7:54 am Subject: iPod?

Will one of these work for iPods as well?


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Close Name:Biff Posts: 1479 Joined: 08 Apr 2004
Fri May 12, 2006 10:30 am Subject:

Is there something Mac specific here? Like its allowing the power management circuitry to get in the right state?

Or is this basically just saying that new batteries in general should be fully charged and then fully discharged once when you first get them?

Either way, definitely good advice for those getting a new laptop. Guest I think it would definitely not hurt if you were to do something similar with a new iPod.


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Close Name:Small White Car Posts: 1960 Joined: 02 Jul 2004
Fri May 12, 2006 11:42 am Subject: Yes

Yes, follow this advice with any battery device you buy. (Well, lithium-ion devices anyway, but that's most of them as far as I know.)

You can learn a LOT more than you care about:
http://www.batteryuniversity.com/parttwo-34.htm


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Close Name:gslusher Posts: 2088 Joined: 13 Nov 2002
Fri May 12, 2006 2:45 pm Subject: PDAs

Quote
Small White Car wrote:
Yes, follow this advice with any battery device you buy. (Well, lithium-ion devices anyway, but that's most of them as far as I know.)


Be careful with some devices. Some PDAs will lose everything in their RAM if you run the battery too low. A few (e.g., Palm TX) don't. Be sure to check the user's guide, first. If you do this with a PDA, do a full sync, first. Discharge the PDA, then fully charge it and do another sync.


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Close Name:WaltFrench Posts: 1 Joined: 27 May 2003
Fri May 12, 2006 4:02 pm Subject: Voodoo?

What's with the "Use it at least 2 hrs" and "sleep at least 5 hours" specs on the MBP?

What supporting documentation / insights do you have? How well-differentiated is this from an old wives' tale or urban legend?

If I'm in a hurry (WTF?!? 5 hours w/o my brand new book?)how much of a difference does this make? And why?

"Inquiring Minds Want to Know!" (R)


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Close Name:Guest
Fri May 12, 2006 4:51 pm Subject: Re: Voodoo

I was thinking the same thing, but the source turns out to be Apple:

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

Daveed


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Close Name:Spider Posts: 2997 Joined: 12 Aug 2001
Sat May 13, 2006 5:40 am Subject:

Yes, the source of these is Apple. I started printing out (albeit with a nicer look) these same exact knowledgebase articles and putting them on every new laptop that goes out the door.

I have had more thanks given because of this than people complaining that I "ruined the look" of the box. Less battery issues seem to be coming in from new users as well.

This advice is very much something to be followed, especially by those who are just getting a Mac or are getting a MacBook Pro. The MacBook Pro and PB 15" SD-DL have quite different batteries than the rest of the portable line.

As well, Apple defines a dead battery as not being able to over 50% of the normal charge time. If calibrated properly Apple is quicker to replace the battery under warranty.


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Close Name:Guest
Sat May 13, 2006 7:45 am Subject: Apple Documentation

The process of calibrating the battery is actually in the manual that ships with the MackBook Pro. It is also in Help. It's also in the PDF version of the MBP manual that's on every new MBP. It's on the Apple site in various guises (support) and also

http://www.apple.com/batteries/

and

http://www.apple.com/batteries/notebooks.html

and

http://docs.info.apple.com/article.html?artnum=18241

and last but not least, the daddy of battery references

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

So I think this will answer most, if not all questions about whether its an old wives' tale or not...


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Close Name:Guest
Sun May 14, 2006 2:06 pm Subject: Calibrate an old Battery?

Does anyone know if there is any value to performing the calibration procedure with an older battery to ensure it's doing the best it can do?

Thanks!


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Close Name:Spider Posts: 2997 Joined: 12 Aug 2001
Sun May 14, 2006 3:03 pm Subject:

It is best to do the calibration right when the battery is new. You can perform it on an older battery, but the results will most likely be nil.


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Close Name:ILYTaZ Posts: 3 Joined: 16 May 2006
Tue May 16, 2006 1:52 pm Subject:

Quote
Spider wrote:
It is best to do the calibration right when the battery is new. You can perform it on an older battery, but the results will most likely be nil.


How's this for a "new battery" 10 days old?

The booklet said that it's best to do it within a week. right now my battery's up to 3 hours. Somewhere I saw that the battery that's been calibrated "withina week" is upto 5-6 hours...

thanks


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Close Name:Guest
Tue May 16, 2006 1:59 pm Subject:

Older is, in my terms, over a month. Ten days and you should be fine.

No guarantees, but I don't see an extra three days hurting it too much.


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Close Name:Guest
Tue May 16, 2006 2:00 pm Subject:

above is me, Spider. I am at work and not signed in.


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Close Name:ILYTaZ Posts: 3 Joined: 16 May 2006
Tue May 16, 2006 2:59 pm Subject:

Quote
Anonymous wrote:
Older is, in my terms, over a month. Ten days and you should be fine.

No guarantees, but I don't see an extra three days hurting it too much.



So you're saying that after I calibrate my battery, then it'll change the hours from 3 hours to 5-6?


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Close Name:ILYTaZ Posts: 3 Joined: 16 May 2006
Thu May 18, 2006 3:11 am Subject: Re: Kiev

after I calibrate my battery.. should I just leave it recharged just until I need to take it out of the house, or what should I let it run on its own, or what?

Thanks


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Close Name:Guest
Fri May 19, 2006 7:50 am Subject: Battery Charging

Another ridiculously complicated thing to remember. Why in the world doesn't the battery charger do any draining automatically? You should be able to plug it in overnight and have it ready in the morning. Better yet, how about a battery that doesn't need this nonsense? Appple has been endlessly inventive, but sometimes they are oblivious to basic problems like this.


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Close Name:Intruder -   TMO Mac Specialist Posts: 3149 Joined: 07 Jul 2004
Fri May 19, 2006 9:46 am Subject:

Please show us a reference to any laptop that does battery conditioning only when needed.


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