01-14-2010, 05:11 PM

If i'm sitting at my desk, can I use the MacBook plugged in? I know the video for the battery says it is okay to plug it in anytime, the tech who set our Mac's up said it is prolly better to let them drain...so who is right here?

01-14-2010, 05:16 PM

plug it in, charge it up, un-plug it let it drain, rinse and repeat.

01-14-2010, 05:21 PM

I keep mine plugged in when I'm using it. When I leave the house or am at school I use it on batteries.

Drain the battery at least once a month is pretty much the regiment that I have been doing for my MB. It's been a little over a year and my battery health is at 95% @ 158 Cycles.

01-14-2010, 05:33 PM

here is what apple has to say on the issue:
Apple - Batteries - Notebooks

Hope this helps
Clay

01-14-2010, 10:46 PM

I've gotta say, when apple said battery lasts for 7 hours, was that a ballpark figure or what? I got my MB the other day and the battery doesn't last longer than 3 hours, maybe 4.

01-14-2010, 10:59 PM

Originally Posted by smackwarm

I've gotta say, when apple said battery lasts for 7 hours, was that a ballpark figure or what? I got my MB the other day and the battery doesn't last longer than 3 hours, maybe 4.

I second that. Its not really a big deal for me because I never have my Mac away from my charger long enough for it to matter, but my Mac last id say for about 4 n half hours until low battery msg appears.

01-14-2010, 11:04 PM

It depends. When I dim the screen to a reasonable level, mine lasts about 7 hours indeed. If Airport is off too, it is even longer. With wireless on and screen at full brightness, it says about 4 hours or 5.

01-15-2010, 10:28 AM

Originally Posted by smackwarm

I've gotta say, when apple said battery lasts for 7 hours, was that a ballpark figure or what? I got my MB the other day and the battery doesn't last longer than 3 hours, maybe 4.

That would be 7 hours idling. If you use it, it will be less. Same with any other computer

Same conversation here Macbook Battery Charging

01-15-2010, 10:42 AM

Ah okay. 7 hours idle makes much more sense. Thanks

01-22-2010, 04:40 PM

So my question is does the MBP still use the battery even when its plugged in?
Does using the MBP while plugged in count as a charge cycle because I think it does with the iPod. Even when it is plugged in it goes through the battery. Does that happen with the MBP too?

Thanks

01-22-2010, 05:04 PM

Originally Posted by emon878

So my question is does the MBP still use the battery even when its plugged in?
Does using the MBP while plugged in count as a charge cycle because I think it does with the iPod. Even when it is plugged in it goes through the battery. Does that happen with the MBP too?

Thanks

Yes, it still uses the battery depending on what you are doing.

No, it does not count charge cycles that way.

My wife has never used her MB (now 2 1/2 years old) on battery alone. It is always plugged in except when I borrow it. It currently has 14 cycles, Coconut battery indicates battery health at 104% and it has been calibrated exactly "one" time. The last time I used it, 3 months ago or so, the thing lasted over 4 hours.

I take care of my battery as recommended, including calibrating once a month. 1st battery lasted me 18 months before it failed to keep me up and running longer than an hour. 2nd one is now down under 2 hours in about the same 18 month period. $100/18 months is <$6 a month. I say pretty darn cheap when you consider what it is we do with these batteries.

I also say, quit freaking worrying about the darn batteries and use your computer the way you want to.

We need to make one battery thread and dump every single one of these things into the bottomless pit.

01-22-2010, 05:32 PM

Leave it plugged in. Calibrate it monthly or bimonthly. Your tech who set it up is wrong.

Sucks for you, Bob. I'm at 110 battery cycles after 10 months, and still get 3 and a half hours with brightness half way on my aluminum macbook, surfing the web with itunes and adium up and running. If I turn down my brightness and run just a browser, i can pull 5 or 6.

01-22-2010, 07:29 PM

NiCad and NiMH batteries needed that cycling periodically to avoid buildup of crystals in the battery that shortened the capacity (the so-called "memory" effect). However, LiIon and other Lithium based batteries don't like the deep cycles the NiCad needs. In fact, LiIon batteries like to be topped up! See this website for more information: Battery University. Note that the recalibration needs to be done every thirty cycles, not thirty days. And also note that even well-cared for Li batteries start to decay 2 years after manufacture.

01-22-2010, 09:26 PM

Personally, I did the "calibration" rather unintentionally after first getting my BlackBook 2.16GHz -- charged it all the way up, ran it all the way down, charged it all the way up again (ie a first "full cycle").

Since then, I do not calibrate it at all, I rarely take it off the power, it rarely gets below 50% battery on those few occasions where its on battery at all. It is still giving me exactly the same capacity and performance I got from it 2.5 years ago.

So despite what Apple says, my experience is that calibration does not have to be done religiously, though I'm sure it's a good idea to do it periodically. What's much more important, in my view, is the number of cycles. In my experience as a former tech, batteries that are cycled a lot tend to die sooner, suggesting that there is some kind of cycle limit to the LiOn batteries so many of us have in our slightly older notebooks.

Apple's own video on their new sealed batteries suggests they can be cycled up to 1000 times before losing serious capacity, and that this is up to 3x more than older (meaning most of ours) LiOn batteries. For the sake of argument, let's say that its really only 2x more -- that still means that someone who runs the battery mostly to empty each day and charges it up each night (say a student for example) should expect to be replacing batteries more often than I do.

Just my experience on this topic.

Cheers
chas_m

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01-23-2010, 10:33 AM

I wish I had known all this when I first got mine a yr and half ago. Didn't find out about calibrating the battery until 6 or 9 months into ownership. And even then I didn't know that keeping it plugged in all the time would help. I'd just charge it to 100%, then use it until I got the low battery warning.
Oh well, my battery probably lasts about 2 hrs now so I just plug it in all the time. I'll break down and order a new one after I get my tax rebate next month. *sigh*