WHOA!!<p>Huge mistake here - he says he cycles his battery! DO NOT DO THIS TO LITHIUM ION BATTERIES! Lithium Ion will last longer by NOT allowing the cells to be fully discharged!<p>This is the opposite of Nickel Metal Hydride and Nickel Cadmium - these types of batteries DO require a full discharge and full recharge in order to provide a longer life.<p>In addition, the number of discharges, the temperature, etc all come into play with lithium ion. These thinner laptops are actually lithium ion polymer, where the materials are folded into packs...much more susceptible to the elements, like heat.<p>Disclaimer: Spent 3 years in the battery field. <a href="http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries" rel="nofollow">http://batteryuniversity.com/learn/article/how_to_prolong_li...</a><p>Edit: Just want to point out that charging a laptop while using it could potentially create more heat, degrading the battery. I'm not sure what is more damaging - letting the li-ion battery drop below 70%, or charge it while the laptop is being used. So many variables!
If your cycle count is 223 and you are nearing 80%, then your battery is defective, plain and simple. Apple will replace it. It's happened to me a couple times and Apple took care of it with no hassles.
Wow, this is an excellent article! Nice visualization of the battery life.<p>I am quite nervous about the battery sealed inside my own new Macbook. Is it better to attempt to use the battery as much as possible in order to get a new one before the 3 year Applecare Warranty expires? Or to maniacally keep the machine plugged in if at all possible? Or simply not to care? The price of a replacement will be high, and I wonder how many years it will even be possible to replace these batteries.<p>The thinness of my laptop is amazing, but I would rather have a battery that is not GLUED inside the machine.
Not an Apple consumer here, but my netbook battery only lasted about one year, and I attribute this rapid failure to my use of a cheap, (I live off-grid) modified sine wave, voltage inverter, but I have no valid proof of my assumption. As likely a cause for the battery failing to take a charge is the fact that I often ran the netbook until the battery charge depleted to the point of shutting the PC down.<p>When I bought my current, pure sine, inverter I noticed that my new battery lasted nearly twice as long, but since switching to FreeBSD last year my second battery quickly bit the dust...<p>I'm expecting the present battery to last somewhere between one and two years, but I'm not taking that expectation to the bank.
>letting the battery cycle*<p>Wait- I thought that was for NiCd batteries and Li-ion batteries where suppose to always be topped off? Furthermore going below 15-20% charge hurts their max charge level?<p>*By cycle he means running it down and charging it up?
I've only recently started collecting data for my Early 2011 MBP, but I'm starting to see a pretty steep decline. From 72% capacity down to 58% in a little over a month feels like I might be nearing the end of life for my battery.<p><pre><code> date | capacity | loadcycles
------------------------------------
2013-07-08 | 4964 (72%) | 527
2013-07-25 | 4566 (66%) | 534
2013-08-05 | 4432 (64%) | 537
2013-08-16 | 4016 (58%) | 542
</code></pre>
Anyone have any advice to stretch its life longer, or is this pretty typical?
As far as I understand, there are two major factors that will shorten the battery life considerably.<p>One is heat. This may not be avoidable depending on the computer usage. My mom "plays" Second Life (for english lessons) and her battery barely lasted two years - expanding to the point that the trackpad on her Macbook Pro was sticking out.<p>Another is leaving the computer plugged in all the time, which will top the battery - and apparently lithium batteries hate that.<p>Some electric cars have the option to only recharge the battery up to 80%, to increase the lifespan. Would it be possible to do the same with laptop batteries? Perhaps by patching the SMC?
One other possibility; does the "battery health" metric actually mean the same thing it did four years ago? My 2012 MBA is showing 92% capacity, and seems to last about as long as it did when new. My 2007 MBP shows ~70% capacity, and lasts about an hour; it lasted about four hours when new. I'm not convinced it's that meaningful a metric.
This discussion is very interesting. I'm puzzled about how to keep batteries working longer, so I looked around for some sources,<p><a href="http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries" rel="nofollow">http://batteryuniversity.com/learn/article/how_to_prolong_li...</a><p><a href="http://lifehacker.com/5875162/how-often-should-i-charge-my-gadgets-battery-to-prolong-its-lifespan" rel="nofollow">http://lifehacker.com/5875162/how-often-should-i-charge-my-g...</a><p><a href="http://www.latimes.com/business/technology/la-fi-tn-five-free-smartphone-battery-apps-20130809,0,2552192.story" rel="nofollow">http://www.latimes.com/business/technology/la-fi-tn-five-fre...</a><p><a href="http://gigaom.com/2013/06/06/new-ti-chips-speed-charge-times-and-extend-battery-life-for-smartphones-tablets/" rel="nofollow">http://gigaom.com/2013/06/06/new-ti-chips-speed-charge-times...</a><p>with background information about batteries. It would be great to hear comments about what these sources say. I need a reality check on how to take better care of batteries in rechargeable devices.
<a href="http://en.wikipedia.org/wiki/Lithium-ion_battery#Battery_life" rel="nofollow">http://en.wikipedia.org/wiki/Lithium-ion_battery#Battery_lif...</a><p>> <i>The rate of degradation of lithium-ion batteries is strongly temperature-dependent; they degrade much faster if stored or used at higher temperatures.</i><p>That might be related. MacBook Airs get <i>really</i> hot even if you aren't doing anything too taxing.
So, this inspired me to collect similar data on my laptop. I'm collecting a few more data points, internal battery temp, individual cell voltage, etc. I'm estimating 30-60 MB/year at 1 minute intervals. My script is available on GitHub here <a href="https://github.com/mikegrb/Battery-Logger" rel="nofollow">https://github.com/mikegrb/Battery-Logger</a>
I've set my thinkpad to 'start charging' when below 40% & 'stop charging' when it reaches 60%. I use it with AC power plugged in while the battery floats ~40-60% charge level. Once a month I power cycle it to re-calibrate the battery. It's been going good for the past 3 years. Shows 500 cycle count with 80-90 hrs/week usage & ~80% capacity.
I have exactly the same laptop, purchased from an Apple store ~14 months ago.<p>I have more than double his cycle count at 569. My battery is at 85% capacity.<p>I'd say your battery is defective, or you were doing something to it that caused it to degrade more rapidly.<p>It's also a little unnerving that the 2009 MBP has an apparently far superior battery, despite Apple's explicit claims to the contrary.
My laptops (two-year-old MacBookPro and three-month-old Thinkpad W530) are plugged in probably 90% of the time I'm using them (8+ hours per day).<p>From reading some of the other comments here, it sounds like I shouldn't use them while they're plugged in. When they're being used 8-12 hours per day, however, it's impossible to avoid.
My 2011 MacBook Pro is doing a lot better than my 2007 one. With similar use, the older MacBook went through about a battery every year and a half, replacing once they could only hold up an hour or so of charge. I'm up to 750 cycles and holding high at 98% "health".<p>The OPs MacBook air sounds defective, or at least, under-performing.
How do you even measure max capacity of the battery? Is it by keeping track of the current balance or is there some other direct physical way to do it?<p>Measuring once per minute seems like massive overkill for a property that changes on a timescale of months, but the interesting question to me is - does it do anything to the life of the battery?
humm, I suppose I should not be too upset then about my Mac Book Pro's battery. It is now a little over 3 years old and I just hit the 500 battery cycles mark this week, about the same time that I noticed my trackpad is no longer working properly. I have had the computer for a while and have not used extensively for over 1 1/2 yrs (have work computer), so I am unsure what it could be, but think it may be the battery. This year we have had a hot weather in the East Coast and my laptop sit out in the changing weather (can't leave the AC on for it), so this may have impacted the battery's lifetime. In general, I can just add that for moderate average use, my Mac Book Pro's battery has lasted quite a bit, but would have liked it to last closer to the 100 cycles promised by Apple's system specs.
Replacing the cells isn't particularly hard if you are willing to take the time with a dremel -- if you're clever you can then close the battery without gluing it.<p>I still have a 4.1 macbook pro that I keep using specifically because it's the last one they made with a user-swappable battery.
I have a Mid 2011 MacBook Pro - so around 2 years old. According to iStat Pro, it's been through 430 cycles with 93% battery health. As far as I can see from the comments, I'm one of the lucky ones.
Although battery health and maintenance is interesting I have never bothered to nurse or baby my batteries on my equipment. If the battery gets to be too short lived its time to replace it.
Are they're people out there that replace their own MB(P|A)?
Is it possible? I know there are hacks out there to take apart and fix chargers (I did it myself).
I'd like to see the Air-vs-Pro graph in terms of mAh instead of percentage of factory capacity. Better yet, in terms of expected running time on a full charge.
I didn't realize battery replacement was such a thing. I have 1856 cycles on a 2008 aluminum macbook with 'normal' health and have never noticed problems. I gather from here [1] that I should be well into my fourth battery?<p>[1] <a href="http://support.apple.com/kb/HT1519" rel="nofollow">http://support.apple.com/kb/HT1519</a>
where are those fuel-cell powered laptops? <a href="http://techland.time.com/2011/12/23/apple-posits-fuel-cell-powered-laptops/" rel="nofollow">http://techland.time.com/2011/12/23/apple-posits-fuel-cell-p...</a>