yea. the second reason sounds right to me.

and why are you so insulting? i don't know why i keep looking at this stupid blog-- at least on weekends. if you're trying to be provocative, just stop. i'm 100% serious.

Various airliners provide power for laptops, often with the caveat that the wattage available is sufficient to run the laptop, or charge the battery, but not both at once. Travelers are told that if the power to their laptop switches off, it's because the combined operating and battery-charging load is too much for the system, and they should shut down, remove the battery, and reboot without it.

I don't know whether the Air (which I imagine to be pretty efficient) would be affected by this, but it's a possibility.

Well...maybe people decide to run on AC adapter when they use of their Mac at home with the hope that it could extend the overall life span of their Li-Ion battery and use it only when they are on the go. I guess it would just extend the battery life usage, so that it might give up charges at 4 years instead of 3. Interesting info though.

Old. This has been an issue since the Santa Rosa MacBook Pros. I used to be one of these .0001% of the population and realized after about one week that my MBP was quite slow. At that time I found out that Apple's argument to do so is the first of the reasons you mentioned, not the second.

What's with all the stupidity here? Let's set some facts straight.
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• This has always been the case. Even the iB G3 and PB G4 throttled down the processor to half the clock if you removed the battery.
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• It's put in place to prevent your Mac from shutting down unexpectedly when the system (under high peak load) suddenly draws more power than the adapter can deliver (45W for the MBA, 65W for the MB, 85W for the MBP).
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• There's no reason to remove your battery. Even if it's totally toast as a *battery* you don't have to remove it. Just leave it in there and use AC power. No harm done.
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• Also Li ion or Li polymere batteries don't need to be removed to extend their lifetime. The only maintenance required is running them down every month or so. Removing and storing batteries to preserve battery health is completely outdated advice (dates far back to NiMh batteries).
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What Apple is doing is smart and as usual they gave this a lot more thought than 99% of the Mac rumor site readers.
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Now read this entire post again. Memorize it. Heed the advice. And don't forget to say thanks to me for offering you dimwits a clue. It was direly needed. ;)

you get a lot more life out of a battery if you charge it to 75% and then store it, and only top it off when you need it. That's why many people (more than your fictitious statistic of .0001) remove their laptop batteries when not in use-- it actually does increase longevity.

Yes of course, I can see somebody buying a MB or MBP and be concerned about spending more money for a new battery after a couple of years HAH! yeah....

C'mon how much more life will you get from the battery anyways ...... maybe you should be more mindful about the life of the cpu and the other components LOL!

I mean while you're at it, it might be a good idea to charge and store the battery in the freezer this way you get more power and more life!

normal pc laptops becomes totally unusable within 3 years. for mac, even if it's just a battery replacement, i suppose it's still a better deal after all.

my batery on my MBP C2D 2.16 died on me after a year and few months of use...

I DID run it copmletely out of power every month or 3 weeks [i have that iStat widget and was monitoring the cycles left, it had 200 plus cycles to go when i started having problems]

It is my first laptop and i used it mostly connected, very few times on batery, and some of those few where to empty the batery... what up with dat???

I would really like to know what happen there... so i can take care of my next batery... my Superdrive died on me too... sort of

When I bought my previous generation MBP last month (I got a great deal because the new ones had just been announced) the sales girl suggested I use it without the battery if I'm going to be plugged in for an extended period, like a week or more according to her. While I have had some extended desk time, I have yet to follow her advice. This was an official reseller, but not a best buy type of place; it was a small Apple-only retailer with staff who seemed to know their Macs quite well.

I hadn't really bothered to develop an opinion on the advice yet; this was my first notebook since my 1998 Wallstreet Powerbook, so I have some knowledge to update. I've been on a desktop powermac since 02.

Well Kev, you know, I actually work for Germany's biggest Apple Retailer and since Germany totally lacks official Apple Stores (one is to open in Munich... but just ONE) we are like THE Apple Store over here.

And while I do think that I got my share of Apple-Knowledge, I'd say that about 50% of my colleagues have no clue what they are talking about in the first place and are either repeating some stuff they heard somewhere else or are just - plain and simply - inventing the things they say.

So either way I highly recommend to ask more than just one person in more than just one place if you wanna make sure the advice given is correct.

As far as you are concerned with your battery life:
Leave it in your MBP even if you work AC powered 24/7.
Just calibrate it every say 4-6 weeks i.e. completely drain the battery and completely recharge it.

This way my MacBook's Battery is still kicking after ~2.5 years !!! (1st Gen MacBooks early 2006)

I rarely use it w/o AC so I only got like 50 load-cycles. The Battery's Health however is STILL at about 98%-94% (iStat Pro's results vary a bit). And according to my very own experience this seems to be 100% correct as I got virtually the SAME time I can use my MacBook on it's battery as I got 2.5yrs ago.

If you should EVER encounter any problems (which can happen) try resetting the PRAM (Boot your Mac holding down CMD+Shift+P+R (keep holding it down until you hear the third startup-chime)) and after that calibrate your battery and you're good to go...

edit: The PRAM reset is CMD+ALT+P+R and NOT (!!!) CMD+SHIFT+P+R !!!

Screw me. I need some coffee!

I have several laptops...and batteries are one of those costs that I don't understand why people are too cheap to pay out for. The second are top quality cases. I love people who buy a $2,000 laptop, and put it in a $60 case, or a $35 sleeve, but that's for a different discussion.

Here's the way I see it:

You go out and spend anywere between $1,200 to >$3,000 on a laptop. And every couple of years, you can't fathom to spend an extra $120-$150 on it? that's between 5-10% of the original purchase price! That's nothing. Give me a break.

I STILL have the original TiBook G4/400, chuggin' right along running 10.4. And in the 7.5 years that I have owned I have needed to purchase ONE extra battery, just ONE. And I bought it on eBay for $60. And that was for a $2,500 laptop.

These machines are designed to be portable, and the bottom line is they don't have the power supply circuitry that the desktop class machines do. So please, just buy a new battery every couple of years, which is the max you should need to buy one anyway. Otherwise, you probably have a problem with your machine, or are doing something wrong.

Oh, and be smart, and use the power management features of the system, they are there for a reason, and in the long run, extend the life of your battery.

And just be happy that Macs run as well as they do on battery power. My f---ing ThinkPad Z61 (4 months old)running XP gets 1.5 hours of battery life with the standard battery. My 7 year-old TiBook with its original battery beats it any day of the week.

I removed the battery to prevent the laptop from heating up , its gotten more comfortable that way and certainly extended the life of the battery (though that wasnt my primary concern).

Why you need to remove it anyway?

I overheard Best Buy associates recommending to customers to remove the battery when using AC power.