How to calibrate your MacBook battery

I have the same problem with the documentation, Henk. If anybody happens upon this month-and-a-half-too-late comment and knows the answer, drop me a line kyle.dobbsATgmail.com

I wanted some advice. I bought a 13 inch Mac Book in July. I recently ran off the battery until the computer shut down. Now, the battery doesn't appear to charge, though the laptop will run off the power adapter. The green light is on, but no charging. What gives?

I'm just doing the very first calibration of the battery on my new MB. What amazes me is how poorly the Apple documentation is written after the "low battery warning dialog on the screen" (Step 3).

We are first instructed in Step 4 "to keep your computer turned on until it goes to sleep." Only then are we told "[s]ave your work [....] before the system goes to sleep." That could be too late for the busy reader...

Step 5 says to "[t]urn off the computer or allow it to sleep for five hours or longer." Not sure what is meant here: wait the five hours minimum only in the case of letting it sleep?
Or also when the computer is turned off? In the latter case a strategically placed comma would have been helpful...

Just my €0.02 worth.

How long can your battery last with wireless on?
Mine lasted about 3 hours 15 mins, is this too short?

Just for us, Macbook & MacbookPro owners, one damn important information : There is a bug with the Intel Core duo, if you take the battery out and leave the computer plugged, the Proc will run at 1 Ghz ! I used to do it with all my previous laptops. Of course the mac does not charge the battery when it is full, BUT, what harms the battery is to get charged when it is 95% full. If you can, always wait for the battery to be empty before charging. I use batteries for a lot of things (I'm cameraman for French TV) and i noticed that doing so makes my (Phone, Comp, Cameras etc) batteries last a little longer.
Anyway, so we have a problem with the Intel Proc. We can't do that anymore :
http://www.increw.com/the_news/latest_news/dont_run_your_macbook_without_batteries.html
I hope there will be some kind of update to fix this !!
Thx a lot for your site, i just discovered it and am impressed by the great work!
:)

Hi fellas,

i just got my now macbook pro (in germany). The information "how to calibrate..." is slightly different to the one mentioned in the link. The German User Book says, that first) I have to use my book until it turns to sleep mode and Secondly) just wait for five or more hours until re-plugging it so that the battery is absolutely empty. So this is a little different, but I guess it makes good sence to get an correct battery information. best wishes from Germany....
P.S. I still love my G4....

P.S. to answers your question Brian: The first G3/G4 books didn´t have a battery to contain the date settings, like PCs still have for many years. but the problem seems to be solved with the new models

"When the battery reaches "empty", the computer is forced into sleep mode. The battery actually keeps back a reserve beyond "empty", to maintain the computer in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, any open files could be lost."

And, in a last dying gasp, it will drain the PRAM battery as well, causing your computer to think it's 1969 the next time you turn it on. At least, that's what my 12" 800 MHz G3 iBook does. Do the new MB/MBPs do that as well?

I don't think any of you know what the hell you're talking about.

If you use your (Mac/Power/i)Book(Pro) computer at home or at the office just don't always plug it in! Use the battery until the low battery warning then plug it in to charge - after a full charge, unplug it and use the battery... And so on :) Calibrate the battery every few months.

Like muscles, li-ion batteries need to be used or they become weaker - of course using them wears them out too, but less than not using them. Basically, li-ion batteries become weaker from the day they are manufactured - that's why it's not a good idea to buy batteries that are sealed in the box without checking the manufacturing date.

"It details the process of 'calibrating' your MacBook's battery, which is very important to the overall lifetime of the battery."

This is misinformation. Calibration *only* affects the battery information displayed in the menu bar and other places in the system. The system needs to know the exact total capacity of the battery in order to provide an accurate percentage remaining. Calibration simply allows the computer to measure it. It helps if you want an accurate battery display, but is *not* something you have to do to avoid damaging your battery.

Removing the battery with the computer plugged in is also unnecessary. The circuitry in Macs is not stupid and will not continue charging the battery after it is full. It won't even begin charging the battery again until the charge drops below 95% to protect it.