12 ms·

The De-evolution of My Laptop Battery

245 points by brendan_gill 13y ago

andrewflnr 13y ago
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.
uptown 13y ago
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. 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 Anyone have any advice to stretch its life longer, or is this pretty typical?
- ballard 13y ago
  mid 2010 5020/5770 (87%) and 393. I'll have to starting track this also.
Silhouette 13y ago
Interesting experiment, but watch out for the vertical scale on the charts showing capacity against time.
- saidajigumi 13y ago
  Yeah, not pegging the axes at zero makes for a much more dramatic graph -- a classic way to lie with data viz. Sometimes it's fine to do that (e.g. because without scaling it's impossible to visually understand some of the data), but the context should be made clear. That said, the plot of the Macbook Air's battery performance vs. the Macbook Pro's is really interesting. I haven't done the tracking, but this agrees with my anecdotal sense is that my 2011 MBP (likewise a main work+personal system) has had really excellent battery longevity relative to prior Mac/other laptops I've used.
nakedrobot2 13y ago
Wow, this is an excellent article! Nice visualization of the battery life. 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. The thinness of my laptop is amazing, but I would rather have a battery that is not GLUED inside the machine.
- rayiner 13y ago
  Its really NBD. My 2010 MBA still holds a solid 5-6 hours, down from maybe 7.
- jradavenport 13y ago
  >Wow, this is an excellent article! Nice visualization of the battery life. Thanks!
- glhaynes 13y ago
  I believe Apple charges $199 for a battery replacement, which is definitely not cheap, but might be worth it if you were still happy with the rest of the machine. I'm not sure how long it takes them to do it, though. I'd expect they'd continue to offer that service for quite a few years to come. As other posters have mentioned, it seems to me like the glued-in batteries don't rapidly decline like the old ones did. I don't have any numbers, though, just impressions.
  - gz5 13y ago
    imo very conscious decision on part of Apple (and PC makers) to provide short battery half lives, rather than spending more money to deal with the size and heat/cooling constraints of laptops, especially the thin lightweight variety. not only saves them money short term, but helps push users to new versions before they really need to jump...
    - 13y ago
YooLi 13y ago
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.
- aeturnum 13y ago
  I had my first macbook's battery replaced. I took it into the apple store for an unrelated problem, the tech noted the awful battery life and asked me how old the laptop was, said, "that's not right...," and grabbed another battery. Nice and easy.
  - untothebreach 13y ago
    If I remember correctly, with the Macbook Air it will have to be '"that's not right...", and grabbed another Macbook Air, and started migrating my data, etc, etc...'
    - mikeevans 13y ago
      They recently replaced the battery on my Macbook Air. They didn't replace the whole computer, just the battery. Took about 15-20 minutes.
      - untothebreach 13y ago
        Ah, I thought the battery was permanently attached to the body.
        pseudonym 13y ago
        The RAM is the thing with Macbook Air's that permanently soldered to the system board. Everything else is difficult to replace due to the form factor, but still replaceable.
    - jaggederest 13y ago
      They're just held in with torx screws, from what I could see of my old 'unibody' mac when I took it apart. Current gen may be different though.
nwh 13y ago
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". The OPs MacBook air sounds defective, or at least, under-performing.
voidlogic 13y ago
>letting the battery cycle* 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? *By cycle he means running it down and charging it up?
- phillmv 13y ago
  Yeah, can someone who knows how this shit works chime in? There's a lot of conjecture on the internet but few answers. Apple's advice seems to be "don't worry, be happy, don't let it be in a discharged state for a very long period of time, occasionally cycle through it". I'm on my third battery for this 2009 Macbook unibody (granted, the first one was water damaged but still…), and 300 cycles in it's starting to give me Service Battery warnings and I must be doing something wrong.
  - kalleboo 13y ago
    There seems to be no exact science with Li-ion battery life. Even defining "life" is difficult, since some people say the batteries "life" ends at 80-50%. Of all the things I've heard about Li-ion batteries, the only ones that haven't been refuted are: - Li-ion batteries like living at around 70%. More or less will decrease their life - Li-ion batteries will always lose 30-50% capacity in 3 years even if they're just lying on a shelf due to their chemistry - Li-ion batteries dislike heat. More heat reduced battery life. Coldness will temporarily reduce capacity, but has no long-term effect on lifespan.
- nakedrobot2 13y ago
  Li-ion batteries do have a memory effect also, but it is apparently quite negligible. Li-ion batteries should NOT be topped up for extended periods; this will shorten their lifespan considerably. When storing a li-ion battery for an extended period, it is best if the battery has around 30% charge. However I am not a real expert on this kind of stuff, please don't take this as gospel, if there is a qualified battery expert who can chime in here, please do :)
- Arjuna 13y ago
netcraft 13y ago
anyone know how to do something similar on a windows laptop?
- jbert 13y ago
  I'd guess: - write a little code to drive this API: http://stackoverflow.com/questions/7785096/read-laptop-battery-status-in-float-double http://stackoverflow.com/questions/7785096/read-laptop-batte... - and either use a task scheduler to run your code every minute, or startup a long-lived process which just does this and sleeps - output in whatever format you like. CSV is obviously good, but given richer APIs on windows you could dump it straight into an excel sheet I guess.
  - Scaevolus 13y ago
    RRDTool is great for storing these sorts of time-series archives, and it will generate pretty graphs as well. You could cobble together an app starting from these StackOverflow postings: Task Scheduling: http://stackoverflow.com/a/2725908 http://stackoverflow.com/a/2725908 RRD interface: https://pypi.python.org/pypi/PyRRD https://pypi.python.org/pypi/PyRRD Battery reading: http://stackoverflow.com/a/6156606 http://stackoverflow.com/a/6156606
- jradavenport 13y ago
  I have no experience with this kind of stuff for Windows, but I really hope somebody wiser than I can do it easily. I assume there must be an equivalent to cron in win8?
- voltagex_ 13y ago
  http://www.techrepublic.com/blog/windows-and-office/check-out-the-health-of-your-device-with-the-windows-8-battery-report/ http://www.techrepublic.com/blog/windows-and-office/check-ou... This one will also output in XML. The APIs should be there in Windows 7, too.
Axsuul 13y ago
My 2012 MacBook Air on a full charge only lasts 2-2.5 hours during an intense coding session. Am I the only one?
- jlgreco 13y ago
  That probably depends wildly on what an "intense coding session" entails. Do you have an IDE that is keeping your CPU pegged by constantly rebuilding everything every time you enter a character? Or do you code in Vim and build every few minutes at the absolute most?
- rsynnott 13y ago
  That seems abnormal, though possibly bad IDE behaviour? What is CPU usage like at this point? Also, might be worth giving this a go: http://software.intel.com/en-us/articles/intel-power-gadget-20 http://software.intel.com/en-us/articles/intel-power-gadget-... Some badly behaved software (notably Netflix's Silverlight thing) will seemingly peg the CPU at maximum turbo-boost frequency for no good reason, which hits power usage hard.
- driverdan 13y ago
  Sounds reasonable if you have your brightness way up and have CPU intensive apps running like VMs.
deleted 13y ago
[deleted]
bradjohnson 13y ago
Link is dead for me, mirror?
sixothree 13y ago
Is this guy really a developer? I can't imagine using a single 15" monitor to accomplish anything at a productive pace.
- fsckin 13y ago
  Single tasking is the new multitasking.
- ryanpetrich 13y ago
  No true Scotsman would do such a thing.
- driverdan 13y ago
  I used 2+ monitors from 2000 to 2010ish. After switching to only laptops I gave up secondary displays and never went back. The only times I miss it is when I want to have docs open. I don't know why you'd need it otherwise.
  - rocky1138 13y ago
    Same. I made the switch when KDE started supporting the Ctrl+Alt+Arrow Keys to spin my desktop around on a six-sided cube. So much handier to flip between sides. I really miss that in Windows.
  - sixothree 13y ago
    That's the thing. I always have multiple docs open - tasks lists, TDS, specifications (I deal with a lot of specifications). As of this typing I have 22 open windows among 3 monitors. Virtual machines, specs, time clock, web browsers, visual studio, skype, SSMS, iTunes, etc. Call me crazy but I cannot imagine having to do all of that on one machine and still be productive.
- cocoflunchy 13y ago
  It's actually a 13" monitor... I guess it helps you focus.
- aerolite 13y ago
rednukleus 13y ago
This is why I prefer replaceable batteries. Ultrabooks look nice, but ultraportables are more practical in my opinion.
rsynnott 13y ago
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.
outworlder 13y ago
As far as I understand, there are two major factors that will shorten the battery life considerably. 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. Another is leaving the computer plugged in all the time, which will top the battery - and apparently lithium batteries hate that. 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?
- ddeck 13y ago
  >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? My laptop (X1 carbon) does this, I assumed most did. The Lenovo power manager let's you choose when to start charging and when to stop. I start below 40% and stop at 85%.
  - outworlder 13y ago
    That's nice. I wasn't aware of notebooks which let you do that.
- GuiA 13y ago
  >Another is leaving the computer plugged in all the time, which will top the battery - and apparently lithium batteries hate that. I thought modern batteries had mechanisms in place to prevent that?
  - outworlder 13y ago
    I'd think that they will actually recharge to somewhat less than 100%. But Apple still recommends unplugging the computer from time to time, so I'm assuming they get to very near full capacity. My laptop is plugged in to a Thunderbolt Display almost all the time, so the battery gets topped off. It says that it is "charged", but I have no idea how much absolute capacity is that. If I'm not going to unplug the notebook anytime soon (not travelling, not weekend), then I should be able to tell to leave it half charged (half, since discharging completely is even worse).
arxpoetica 13y ago
Hilarious that I thought to post this on HN, and there it was, at the top...
sengstrom 13y ago
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? 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?
- cliveowen 13y ago
  Mac OS X makes the stats available directly from the battery.
  - sengstrom 13y ago
    Yes, but how does it arrive at the number it reports?
    - rocky1138 13y ago
      One assumes by the mAh.
cinquemb 13y ago
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).
- nekopa 13y ago
  How did you fix your charger? I have always thought that we (users) shouldn't have to worry about charging, over-charging, stretching the battery (I have honestly heard people talking about this) and so on. We have the tech to make smart chargers, why aren't they here yet? {OT: has anyone else thought why we don't have a full bay size laptop battery that can be put inside a desktop for those times the power goes out, but we don't want/need a UPS?}
  - cinquemb 13y ago
    One of the wires broke inside of the magsafe. So with some pliers I opened it up, then cut the broken part, strip the tip to expose the connection, reconnected it (tested it and put some electric tape around it to be sure), and assembled it back together with tiny amounts of hot glue on the edges. I wish they designed things so they can be taken apart easier. I'm not sure if this is really "fixing the charger" but some people decided to solder off the tips connection to the board, cutting the bad part, and soldering it back (I didn't want to do that much work). I think for most users, they shouldn't have to worry about it, but I feel like there should be the ability in the hardware/software for users to have the ability to maintain/mod their own systems if they please.
thehme 13y ago
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.
JimmaDaRustla 13y ago
WHOA!! 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! 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. 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. Disclaimer: Spent 3 years in the battery field. http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries http://batteryuniversity.com/learn/article/how_to_prolong_li... 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!
- thehme 13y ago
  I believe you are correct on the "cycling the battery", which I believe you want to avoid, so that you battery will be able to charge fully for longer. "A charge cycle means using all of the battery’s power, but that doesn’t necessarily mean a single charge. For instance, you could listen to your iPod for a few hours one day, using half its power, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two, so you may take several days to complete a cycle. Each time you complete a charge cycle, it diminishes battery capacity slightly, but you can put notebook, iPod, and iPhone batteries through many charge cycles before they will only hold 80% of original battery capacity." - http://www.apple.com/batteries/ http://www.apple.com/batteries/ http://support.apple.com/kb/HT1519 http://support.apple.com/kb/HT1519
  - JimmaDaRustla 13y ago
    There are mixed meanings in the definition of "cycle", but both make sense, just depends on the context. Thanks for the blurb! He does state "letting the battery" cycle, so I'm assuming he is implying the battery is being allowed to be discharged near fully.
post_break 13y ago
I have 378 cycles, 90% capacity. Original capacity, 4680mAh, current capacity 4228mAh. Same laptop as him. Mac is 18 months old. His must be flawed.
D9u 13y ago
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. 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... I'm expecting the present battery to last somewhere between one and two years, but I'm not taking that expectation to the bank.
- Sheepshow 13y ago
  To confirm or disprove your idea, you could look at the output of the battery charger rather than the input to it. In general, AC-DC converters are pretty insensitive to the harmonic content of the AC input because their role is to remove any harmonic content they do find. They do this with huge low-pass filters with corner frequencies well under 1Hz, whether the charger is either linear (unlikely) or switching (much more likely). When AC becomes distorted, you start seeing harmonics (i.e. contributions at higher frequencies). Low pass filters are progressively more effective at higher frequencies. This is to say, I wouldn't be at all surprised if the efficiency of the charger itself suffered, but the output voltage was unaffected, meaning the laptop was unaffected.
  - D9u 13y ago
    Interesting, but does using a DC to AC inverter change anything? I've noticed that cell phone batteries also failed prematurely when I had the modified sine inverter. Do you mean that if my charger was operating with less efficiency due to modified sine wave input then my batteries were not likely to be affected?
    - XorNot 13y ago
      It's more likely that you were simply cycling the batteries more aggressively due to the circumstances which led to you using a DC-AC inverter.
tokenadult 13y ago
This discussion is very interesting. I'm puzzled about how to keep batteries working longer, so I looked around for some sources, http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries http://batteryuniversity.com/learn/article/how_to_prolong_li... http://lifehacker.com/5875162/how-often-should-i-charge-my-gadgets-battery-to-prolong-its-lifespan http://lifehacker.com/5875162/how-often-should-i-charge-my-g... http://www.latimes.com/business/technology/la-fi-tn-five-free-smartphone-battery-apps-20130809,0,2552192.story http://www.latimes.com/business/technology/la-fi-tn-five-fre... http://gigaom.com/2013/06/06/new-ti-chips-speed-charge-times-and-extend-battery-life-for-smartphones-tablets/ http://gigaom.com/2013/06/06/new-ti-chips-speed-charge-times... 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.
kingsofwildcat 13y ago
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? [1] http://support.apple.com/kb/HT1519 http://support.apple.com/kb/HT1519
Cyph0n 13y ago
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.
spiritplumber 13y ago
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. 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.
ballard 13y ago
2010 MBP MC374LL/A :: Cycles: 393 Health: %87
rcthompson 13y ago
Hmm. I've already hit 100 cycles after only 3 months of owning my Macbook Retina 13-inch... I guess that makes me a ... power user? ;)
jlgaddis 13y ago
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). 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.
Zoomla 13y ago
where are those fuel-cell powered laptops? http://techland.time.com/2011/12/23/apple-posits-fuel-cell-powered-laptops/ http://techland.time.com/2011/12/23/apple-posits-fuel-cell-p...
enscr 13y ago
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.
ahoge 13y ago
http://en.wikipedia.org/wiki/Lithium-ion_battery#Battery_life http://en.wikipedia.org/wiki/Lithium-ion_battery#Battery_lif... > The rate of degradation of lithium-ion batteries is strongly temperature-dependent; they degrade much faster if stored or used at higher temperatures. That might be related. MacBook Airs get really hot even if you aren't doing anything too taxing.
OMBUG 13y ago
Nice article, might start tracking this too! My mid-2011 MBA is at 203 cycles and 99.5% capacity. Seems to be holding up remarkably well.
mchanson 13y ago
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.
aroman 13y ago
I have exactly the same laptop, purchased from an Apple store ~14 months ago. I have more than double his cycle count at 569. My battery is at 85% capacity. I'd say your battery is defective, or you were doing something to it that caused it to degrade more rapidly. It's also a little unnerving that the 2009 MBP has an apparently far superior battery, despite Apple's explicit claims to the contrary.
mikegrb 13y ago
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 https://github.com/mikegrb/Battery-Logger https://github.com/mikegrb/Battery-Logger

245 points by brendan_gill 13y ago

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.

uptown 13y ago

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. 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 Anyone have any advice to stretch its life longer, or is this pretty typical?

ballard 13y ago
mid 2010 5020/5770 (87%) and 393. I'll have to starting track this also.

Silhouette 13y ago

Interesting experiment, but watch out for the vertical scale on the charts showing capacity against time.

saidajigumi 13y ago
Yeah, not pegging the axes at zero makes for a much more dramatic graph -- a classic way to lie with data viz. Sometimes it's fine to do that (e.g. because without scaling it's impossible to visually understand some of the data), but the context should be made clear. That said, the plot of the Macbook Air's battery performance vs. the Macbook Pro's is really interesting. I haven't done the tracking, but this agrees with my anecdotal sense is that my 2011 MBP (likewise a main work+personal system) has had really excellent battery longevity relative to prior Mac/other laptops I've used.

nakedrobot2 13y ago

Wow, this is an excellent article! Nice visualization of the battery life. 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. The thinness of my laptop is amazing, but I would rather have a battery that is not GLUED inside the machine.

rayiner 13y ago
Its really NBD. My 2010 MBA still holds a solid 5-6 hours, down from maybe 7.
jradavenport 13y ago
>Wow, this is an excellent article! Nice visualization of the battery life. Thanks!
glhaynes 13y ago
I believe Apple charges $199 for a battery replacement, which is definitely not cheap, but might be worth it if you were still happy with the rest of the machine. I'm not sure how long it takes them to do it, though. I'd expect they'd continue to offer that service for quite a few years to come. As other posters have mentioned, it seems to me like the glued-in batteries don't rapidly decline like the old ones did. I don't have any numbers, though, just impressions.
- gz5 13y ago
  imo very conscious decision on part of Apple (and PC makers) to provide short battery half lives, rather than spending more money to deal with the size and heat/cooling constraints of laptops, especially the thin lightweight variety. not only saves them money short term, but helps push users to new versions before they really need to jump...
  - 13y ago

YooLi 13y ago

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.

aeturnum 13y ago
I had my first macbook's battery replaced. I took it into the apple store for an unrelated problem, the tech noted the awful battery life and asked me how old the laptop was, said, "that's not right...," and grabbed another battery. Nice and easy.
- untothebreach 13y ago
  If I remember correctly, with the Macbook Air it will have to be '"that's not right...", and grabbed another Macbook Air, and started migrating my data, etc, etc...'
  - mikeevans 13y ago
    They recently replaced the battery on my Macbook Air. They didn't replace the whole computer, just the battery. Took about 15-20 minutes.
    - untothebreach 13y ago
      Ah, I thought the battery was permanently attached to the body.
      - pseudonym 13y ago
        The RAM is the thing with Macbook Air's that permanently soldered to the system board. Everything else is difficult to replace due to the form factor, but still replaceable.
  - jaggederest 13y ago
    They're just held in with torx screws, from what I could see of my old 'unibody' mac when I took it apart. Current gen may be different though.

nwh 13y ago

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". The OPs MacBook air sounds defective, or at least, under-performing.

voidlogic 13y ago

>letting the battery cycle* 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? *By cycle he means running it down and charging it up?

phillmv 13y ago
Yeah, can someone who knows how this shit works chime in? There's a lot of conjecture on the internet but few answers. Apple's advice seems to be "don't worry, be happy, don't let it be in a discharged state for a very long period of time, occasionally cycle through it". I'm on my third battery for this 2009 Macbook unibody (granted, the first one was water damaged but still…), and 300 cycles in it's starting to give me Service Battery warnings and I must be doing something wrong.
- kalleboo 13y ago
  There seems to be no exact science with Li-ion battery life. Even defining "life" is difficult, since some people say the batteries "life" ends at 80-50%. Of all the things I've heard about Li-ion batteries, the only ones that haven't been refuted are: - Li-ion batteries like living at around 70%. More or less will decrease their life - Li-ion batteries will always lose 30-50% capacity in 3 years even if they're just lying on a shelf due to their chemistry - Li-ion batteries dislike heat. More heat reduced battery life. Coldness will temporarily reduce capacity, but has no long-term effect on lifespan.
nakedrobot2 13y ago
Li-ion batteries do have a memory effect also, but it is apparently quite negligible. Li-ion batteries should NOT be topped up for extended periods; this will shorten their lifespan considerably. When storing a li-ion battery for an extended period, it is best if the battery has around 30% charge. However I am not a real expert on this kind of stuff, please don't take this as gospel, if there is a qualified battery expert who can chime in here, please do :)
Arjuna 13y ago

netcraft 13y ago

anyone know how to do something similar on a windows laptop?

jbert 13y ago
I'd guess: - write a little code to drive this API: http://stackoverflow.com/questions/7785096/read-laptop-battery-status-in-float-double http://stackoverflow.com/questions/7785096/read-laptop-batte... - and either use a task scheduler to run your code every minute, or startup a long-lived process which just does this and sleeps - output in whatever format you like. CSV is obviously good, but given richer APIs on windows you could dump it straight into an excel sheet I guess.
- Scaevolus 13y ago
  RRDTool is great for storing these sorts of time-series archives, and it will generate pretty graphs as well. You could cobble together an app starting from these StackOverflow postings: Task Scheduling: http://stackoverflow.com/a/2725908 http://stackoverflow.com/a/2725908 RRD interface: https://pypi.python.org/pypi/PyRRD https://pypi.python.org/pypi/PyRRD Battery reading: http://stackoverflow.com/a/6156606 http://stackoverflow.com/a/6156606
jradavenport 13y ago
I have no experience with this kind of stuff for Windows, but I really hope somebody wiser than I can do it easily. I assume there must be an equivalent to cron in win8?
voltagex_ 13y ago
http://www.techrepublic.com/blog/windows-and-office/check-out-the-health-of-your-device-with-the-windows-8-battery-report/ http://www.techrepublic.com/blog/windows-and-office/check-ou... This one will also output in XML. The APIs should be there in Windows 7, too.

Axsuul 13y ago

My 2012 MacBook Air on a full charge only lasts 2-2.5 hours during an intense coding session. Am I the only one?

jlgreco 13y ago
That probably depends wildly on what an "intense coding session" entails. Do you have an IDE that is keeping your CPU pegged by constantly rebuilding everything every time you enter a character? Or do you code in Vim and build every few minutes at the absolute most?
rsynnott 13y ago
That seems abnormal, though possibly bad IDE behaviour? What is CPU usage like at this point? Also, might be worth giving this a go: http://software.intel.com/en-us/articles/intel-power-gadget-20 http://software.intel.com/en-us/articles/intel-power-gadget-... Some badly behaved software (notably Netflix's Silverlight thing) will seemingly peg the CPU at maximum turbo-boost frequency for no good reason, which hits power usage hard.
driverdan 13y ago
Sounds reasonable if you have your brightness way up and have CPU intensive apps running like VMs.

deleted 13y ago

[deleted]

bradjohnson 13y ago

Link is dead for me, mirror?

sixothree 13y ago

Is this guy really a developer? I can't imagine using a single 15" monitor to accomplish anything at a productive pace.

fsckin 13y ago
Single tasking is the new multitasking.
ryanpetrich 13y ago
No true Scotsman would do such a thing.
driverdan 13y ago
I used 2+ monitors from 2000 to 2010ish. After switching to only laptops I gave up secondary displays and never went back. The only times I miss it is when I want to have docs open. I don't know why you'd need it otherwise.
- rocky1138 13y ago
  Same. I made the switch when KDE started supporting the Ctrl+Alt+Arrow Keys to spin my desktop around on a six-sided cube. So much handier to flip between sides. I really miss that in Windows.
- sixothree 13y ago
  That's the thing. I always have multiple docs open - tasks lists, TDS, specifications (I deal with a lot of specifications). As of this typing I have 22 open windows among 3 monitors. Virtual machines, specs, time clock, web browsers, visual studio, skype, SSMS, iTunes, etc. Call me crazy but I cannot imagine having to do all of that on one machine and still be productive.
cocoflunchy 13y ago
It's actually a 13" monitor... I guess it helps you focus.
aerolite 13y ago

rednukleus 13y ago

This is why I prefer replaceable batteries. Ultrabooks look nice, but ultraportables are more practical in my opinion.

rsynnott 13y ago

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.

outworlder 13y ago

As far as I understand, there are two major factors that will shorten the battery life considerably. 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. Another is leaving the computer plugged in all the time, which will top the battery - and apparently lithium batteries hate that. 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?

ddeck 13y ago
>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? My laptop (X1 carbon) does this, I assumed most did. The Lenovo power manager let's you choose when to start charging and when to stop. I start below 40% and stop at 85%.
- outworlder 13y ago
  That's nice. I wasn't aware of notebooks which let you do that.
GuiA 13y ago
>Another is leaving the computer plugged in all the time, which will top the battery - and apparently lithium batteries hate that. I thought modern batteries had mechanisms in place to prevent that?
- outworlder 13y ago
  I'd think that they will actually recharge to somewhat less than 100%. But Apple still recommends unplugging the computer from time to time, so I'm assuming they get to very near full capacity. My laptop is plugged in to a Thunderbolt Display almost all the time, so the battery gets topped off. It says that it is "charged", but I have no idea how much absolute capacity is that. If I'm not going to unplug the notebook anytime soon (not travelling, not weekend), then I should be able to tell to leave it half charged (half, since discharging completely is even worse).

arxpoetica 13y ago

Hilarious that I thought to post this on HN, and there it was, at the top...

sengstrom 13y ago

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? 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?

cliveowen 13y ago
Mac OS X makes the stats available directly from the battery.
- sengstrom 13y ago
  Yes, but how does it arrive at the number it reports?
  - rocky1138 13y ago
    One assumes by the mAh.

cinquemb 13y ago

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).

nekopa 13y ago
How did you fix your charger? I have always thought that we (users) shouldn't have to worry about charging, over-charging, stretching the battery (I have honestly heard people talking about this) and so on. We have the tech to make smart chargers, why aren't they here yet? {OT: has anyone else thought why we don't have a full bay size laptop battery that can be put inside a desktop for those times the power goes out, but we don't want/need a UPS?}
- cinquemb 13y ago
  One of the wires broke inside of the magsafe. So with some pliers I opened it up, then cut the broken part, strip the tip to expose the connection, reconnected it (tested it and put some electric tape around it to be sure), and assembled it back together with tiny amounts of hot glue on the edges. I wish they designed things so they can be taken apart easier. I'm not sure if this is really "fixing the charger" but some people decided to solder off the tips connection to the board, cutting the bad part, and soldering it back (I didn't want to do that much work). I think for most users, they shouldn't have to worry about it, but I feel like there should be the ability in the hardware/software for users to have the ability to maintain/mod their own systems if they please.

thehme 13y ago

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.

JimmaDaRustla 13y ago

WHOA!! 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! 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. 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. Disclaimer: Spent 3 years in the battery field. http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries http://batteryuniversity.com/learn/article/how_to_prolong_li... 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!

thehme 13y ago
I believe you are correct on the "cycling the battery", which I believe you want to avoid, so that you battery will be able to charge fully for longer. "A charge cycle means using all of the battery’s power, but that doesn’t necessarily mean a single charge. For instance, you could listen to your iPod for a few hours one day, using half its power, and then recharge it fully. If you did the same thing the next day, it would count as one charge cycle, not two, so you may take several days to complete a cycle. Each time you complete a charge cycle, it diminishes battery capacity slightly, but you can put notebook, iPod, and iPhone batteries through many charge cycles before they will only hold 80% of original battery capacity." - http://www.apple.com/batteries/ http://www.apple.com/batteries/ http://support.apple.com/kb/HT1519 http://support.apple.com/kb/HT1519
- JimmaDaRustla 13y ago
  There are mixed meanings in the definition of "cycle", but both make sense, just depends on the context. Thanks for the blurb! He does state "letting the battery" cycle, so I'm assuming he is implying the battery is being allowed to be discharged near fully.

post_break 13y ago

I have 378 cycles, 90% capacity. Original capacity, 4680mAh, current capacity 4228mAh. Same laptop as him. Mac is 18 months old. His must be flawed.

D9u 13y ago

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. 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... I'm expecting the present battery to last somewhere between one and two years, but I'm not taking that expectation to the bank.

Sheepshow 13y ago
To confirm or disprove your idea, you could look at the output of the battery charger rather than the input to it. In general, AC-DC converters are pretty insensitive to the harmonic content of the AC input because their role is to remove any harmonic content they do find. They do this with huge low-pass filters with corner frequencies well under 1Hz, whether the charger is either linear (unlikely) or switching (much more likely). When AC becomes distorted, you start seeing harmonics (i.e. contributions at higher frequencies). Low pass filters are progressively more effective at higher frequencies. This is to say, I wouldn't be at all surprised if the efficiency of the charger itself suffered, but the output voltage was unaffected, meaning the laptop was unaffected.
- D9u 13y ago
  Interesting, but does using a DC to AC inverter change anything? I've noticed that cell phone batteries also failed prematurely when I had the modified sine inverter. Do you mean that if my charger was operating with less efficiency due to modified sine wave input then my batteries were not likely to be affected?
  - XorNot 13y ago
    It's more likely that you were simply cycling the batteries more aggressively due to the circumstances which led to you using a DC-AC inverter.

tokenadult 13y ago

This discussion is very interesting. I'm puzzled about how to keep batteries working longer, so I looked around for some sources, http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries http://batteryuniversity.com/learn/article/how_to_prolong_li... http://lifehacker.com/5875162/how-often-should-i-charge-my-gadgets-battery-to-prolong-its-lifespan http://lifehacker.com/5875162/how-often-should-i-charge-my-g... http://www.latimes.com/business/technology/la-fi-tn-five-free-smartphone-battery-apps-20130809,0,2552192.story http://www.latimes.com/business/technology/la-fi-tn-five-fre... http://gigaom.com/2013/06/06/new-ti-chips-speed-charge-times-and-extend-battery-life-for-smartphones-tablets/ http://gigaom.com/2013/06/06/new-ti-chips-speed-charge-times... 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.

kingsofwildcat 13y ago

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? [1] http://support.apple.com/kb/HT1519 http://support.apple.com/kb/HT1519

Cyph0n 13y ago

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.

spiritplumber 13y ago

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. 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.

ballard 13y ago

2010 MBP MC374LL/A :: Cycles: 393 Health: %87

rcthompson 13y ago

Hmm. I've already hit 100 cycles after only 3 months of owning my Macbook Retina 13-inch... I guess that makes me a ... power user? ;)

jlgaddis 13y ago

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). 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.

Zoomla 13y ago

where are those fuel-cell powered laptops? http://techland.time.com/2011/12/23/apple-posits-fuel-cell-powered-laptops/ http://techland.time.com/2011/12/23/apple-posits-fuel-cell-p...

enscr 13y ago

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.

ahoge 13y ago

http://en.wikipedia.org/wiki/Lithium-ion_battery#Battery_life http://en.wikipedia.org/wiki/Lithium-ion_battery#Battery_lif... > The rate of degradation of lithium-ion batteries is strongly temperature-dependent; they degrade much faster if stored or used at higher temperatures. That might be related. MacBook Airs get really hot even if you aren't doing anything too taxing.

OMBUG 13y ago

Nice article, might start tracking this too! My mid-2011 MBA is at 203 cycles and 99.5% capacity. Seems to be holding up remarkably well.

mchanson 13y ago

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.

aroman 13y ago

I have exactly the same laptop, purchased from an Apple store ~14 months ago. I have more than double his cycle count at 569. My battery is at 85% capacity. I'd say your battery is defective, or you were doing something to it that caused it to degrade more rapidly. It's also a little unnerving that the 2009 MBP has an apparently far superior battery, despite Apple's explicit claims to the contrary.

mikegrb 13y ago

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 https://github.com/mikegrb/Battery-Logger https://github.com/mikegrb/Battery-Logger