Always on power, is it harmful?

Discussion in 'MacBook Pro' started by Cue, Oct 17, 2006.

  1. Cue macrumors regular

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    #1
    Hi there,

    I finally got my macbook! :D
    This is actually my both my first mac and notebook :)

    Is it alright to have it always on power or should I use it on batteries and only when it gets on low I should connect it?

    Thanks!
     
  2. gauchogolfer macrumors 603

    gauchogolfer

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    #2
    You will strain the battery the least if you keep it plugged in as much as possible. Batteries only have so many charge/discharge cycles in them, so conserve where you can.
     
  3. brikeh macrumors 6502a

    brikeh

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    #3
    I have my pb on an iCurve connected to ext mouse, keyboard an monitor. Should I remove the battery when Im using the laptop like this? :confused:
     
  4. gauchogolfer macrumors 603

    gauchogolfer

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    #4
    There's no need to remove the battery. Once it's charged up, it doesn't continue to draw power. By leaving the battery in, you are protected in case of power-outages, etc.
     
  5. Cue thread starter macrumors regular

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    #5
    I was under the impression that Lithium batteries should be constantly charged as opposed to Ni-Cd and had not such problem.

    Anymore feedback on this please? :/
     
  6. Zic macrumors member

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  7. gauchogolfer macrumors 603

    gauchogolfer

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    #7
    I think we're saying the same thing here. By leaving it plugged in you are keeping it 'constantly charged', but not constantly charging. All batteries have a certain number of charge/discharge cycles, but Lithium batteries are nice in that if you discharge from 100% to 50%, then charge back to 100%, then discharge again to 50%, that counts as 1 cycle, since it went down a total of 100%. Some older batteries would count this as 2 cycles.
     
  8. Yannick macrumors member

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    #8
    exactly, couldn't have said it better
     
  9. Jiddick ExRex macrumors 65816

    Jiddick ExRex

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    #9
    Do make sure to calibrate it once a month though. Else it will not keep the cells in the battery moving...
     
  10. miles01110 macrumors Core

    miles01110

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    #10
    Just calibrate your battery once a month and it will last you for a good 2 years or more.
     
  11. Cue thread starter macrumors regular

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    #11

    Thanks for the links!
    I thought that once fully charged, the notebook would draw power directly from current.

    Apple's website though states that
    So that answers my question I guess.
    It feels kinda strange though, thinking that I have to have my notebook run on battery while at the office and plug the power every 4 hours to charge it back again...
     
  12. gauchogolfer macrumors 603

    gauchogolfer

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    #12
    The statement from Apple is meant to remind you to use the battery every once in awhile, not all the time. I certainly wouldn't recommend running on battery while at the office, then charging up. This will prematurely shorten your battery life. As the others have said, use wall power when you can, use battery when you can't, and every month or so do the calibration procedure. It's the best way to go.

    Note that the ratio of battery/wall power is probably 1/4 or 1/6 in a case like this.
     
  13. Mitthrawnuruodo Moderator emeritus

    Mitthrawnuruodo

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    #13
    Actually no... the best thing is to use the batteries all the time. Discharging/recharging once a month is just to make sure it doesn't just fade away, for those who don't use the battery all the time... :)

    [Link]
     
  14. gauchogolfer macrumors 603

    gauchogolfer

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    #14
    It's funny that we both quoted the same thing, yet interpreted it differently. I read that to mean "use your laptop on the train for an hour, then charge at work for 8 hours, then use for an hour on the way home". It seems to me that this would mean the laptop is being used mostly in a charged-up state, rather than constantly cycling the batteries.
     
  15. NJuul macrumors 6502

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    #15
    I believe this would be the correct interpretation, as all batteries no matter type have a limited number of charge/recharge cycles in them. If you constantly used your battery it would be dead in 6 months.
     
  16. Mitthrawnuruodo Moderator emeritus

    Mitthrawnuruodo

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    #16
    It's all in the bolding... ;)

    And I don't even think we disagree, I was just nitpicking on details... :)

    The main thing, with LI batteries is to use them. They don't have "memory" like earlier generation of rechargeable batteries had, so you don't have to fully discharge and recharge them all the time, but they need to be used to "keep the juices flowing" as Apple puts it.

    So, your advice "use wall power when you can, use battery when you can't" are sound, as long as you don't use it on wall power all the time... a variant of that advice, that might be even better is to "use the battery whenever you can, and wall power when you must**". It's better to use the battery a little bit every day, than just having it connected to wall power all the time and calibrate once a month... :)

    ** Not only for recharging, but also for heavy tasks when you need wall power for performance...

    Just note that I'm lazy and keep my MacBook connected to the wall power most of the time when I'm at home, myself. So I don't even follow my own advice... :eek: ;)

    Edit: And I don't mean you should use it without cord all the time and just connect it when you need charge (or performance), even if that is how you normally use a cellphone, just that, ideally, you should use your battery a bit as often as you can... :)

    Well, since all LI batteries are built to last for at least 500 full charging cycles (if used properly, as described above), it should last you a bit longer than that... let's say you perform a full charge cycle every other day, then the battery should last at least 3 years. Less if you mistreat it, of course... :)
     
  17. Cue thread starter macrumors regular

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    #17
    Wow, I'm utterly lost now! :)

    Imagine I'm in the office. What should I do?
    Use it on battery then charge it when I get the warning?
    Have it on power all the time?

    Same applies for home.

    So thinking that my day trip is home to office and vice versa, how often should I run it on battery? :confused:
     
  18. Mitthrawnuruodo Moderator emeritus

    Mitthrawnuruodo

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    #18
    He-he... don't worry.

    If you use the battery to (or from) work, then just plug it in again when you arrive. There's no need - on a day-to-day basis** - to fully discharge the battery before you recharge. Same thing if you need to use it on battery before the battery is fully charged: Just unplug it, use it and recharge it later when you can or must.

    If you only use it at the office and at home, you can always keep it plugged in**, but I suggest you use the battery a bit a couple of times a week (not necessarily every day, and it don't have to be a full calibration).

    An example:

    As long as I took my old iBook to and from University at least 3 to 4 times a week, and used it for at least 2 hours each time, the battery held it's charge excellently. It was well over 90% of original charge, even after a couple of years. Then I graduated, and just kept it plugged in all the time (I might even have skipped the monthly calibration once or twice), and shortly after the battery was down to just over 60% capacity. Then I started unplugging it for various time periods a couple of times a week, in addition to the monthly calibration (of which I'm reminded by Apple's iCal reminder) and when I returned the iBook battery some weeks ago, it still held over 60% of the original charge.

    ** as long as you remember to do a full calibration every once in a while, at least once a month, as Apple recommends.
     
  19. NJuul macrumors 6502

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    #19
    Well, of course 6 months was an exaggeration in most cases, however Apple states that a properly maintained notebook should retain 80% capacity after 300 cycles. Thus, as my battery life is about 2.5 h, I would go through 2-3 battery cycles per day if I were only to use battery as suggested, and thus 300 cycles would not be far into the future.
     
  20. bearbo macrumors 68000

    bearbo

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    Jul 20, 2006
    #20
    i believe sony is the maker of the battery?

    anyhow, a few yrs back i had a sony laptop, i misinformedly left the battery in the computer and left the computer plugged in all the time, 2 yrs later, the battery holds about half of the charge... then i was told i wasn't supposed to do that. it's a Li-ion battery

    i was told that the computer, once become fully charged, start using the battery until it gets down to 99% and then start charging again... which is what hurted the battery

    perhaps right now macbook/pros don't go the same route, perhaps right now once it's fully charged, it just leaves the battery there, but i, when i plug it in the wall, i take out the battery

    i have a thinkpad that i leave out the battery when i plugged in, it's been...3 yrs or so, it still holds 7 hrs of charge at reg. use
     
  21. YS2003 macrumors 68020

    YS2003

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    #21
    My Ti is over 4 years old now. It is still with the original battery. It charges up to 95 to 98 % and I can sustain the battery live even with the plug out of the power outlet. It has been a desk top queen most of the time and occasional "battery agitation" by un-plugging from the power source once very 2 months or so. When there is the power outlet, I always plug in for my portables.
     
  22. Mitthrawnuruodo Moderator emeritus

    Mitthrawnuruodo

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    #22
    I'm hoping Apple, as usual, is just playing it safe... ;)

    It should last at least a bit longer in most cases, and much longer in some cases, as long as you use it and don't store it.

    If you need to store the battery, discharge it to ~40% and put in the refrigerator. Do not store it in room temperature or higher. (And remember if you keep your Laptop plugged in all the time, you are - essentially - storing the battery at room temperature and 100% charge. This is the worst thing you can do to a LI battery.)
     
  23. NJuul macrumors 6502

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    Boston
    #23
    The battery in both MacBook and MacBook Pro wont charge unless it's below 95% total charge, so this shouldn't be an issue.

    I know this is true for normal liquid lithium batteries, but how about the lithium polymers? I remember reading they are much more resistant to loss of capacity, but I really can't remember where.
     
  24. joebells macrumors 6502

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    #24
    I'd take the battery out of my macbook but the macbook will only run at 1 gigahertz if the battery is removed so thats not an option.
     
  25. JloR macrumors newbie

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    Oct 18, 2006
    Location:
    Denmark
    #25
    I really just reply to say a big thank you.

    I read the apple notes on battery usage, but had no idea how it really was in real life - as opposed to theory.
    I appreciate all the input here, especially the live experience of Mitthrawnuruodo (Hi neighbour).

    At the moment I'm waiting for the store to receive my MB Black ed. and then I'd probably have to setup iCal to remind me not to destroy the battery ;) The x86 laptop I have at the moment has less than 30% battery life left. It's around 1½ years old. I have special powers :)


    Hopefully it will be okay if I leave it on power here at home whenever I'm not at university, and then just take it with me on standby/hibernation for those 4-8 hours a day. And possibly with me at work as well. So it will be turned on and left on power from the wall here at home the rest of the day.
    I keep my laptop turned on 24 hours a day.. A bad habbit.

    Would this still be ok - as long as it runs on battery at work/university and I calibrate every month or more?
     

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