Will letting my battery die shorten it's lifespan?

Discussion in 'MacBook Pro' started by Luzzio, Feb 23, 2008.

  1. Luzzio macrumors regular

    Luzzio

    Joined:
    Feb 12, 2008
    Location:
    Malaysia
    #1
    That's such an ironic thread title.

    Anyway, your humble newbie would like to ask, when I decide to calibrate my MB, or actually bring it outside to use where there's no way to recharge, would letting it's battery fully drain till the MB shuts down shorten it's lifespan?

    Or is it better to fully drain before recharging?

    I went through some threads here, and though it seems to be recommended that we allow the MB to run on it's battery once in awhile to 'caibrate', I'm not sure how far we have to drain it...

    Thanks in advance.
     
  2. MrT8064 macrumors 6502a

    MrT8064

    Joined:
    Jun 7, 2006
    Location:
    UK
    #2
    i dont think it should matter, it am pretty sure they say 300 cycles before you loose 20% of battery,

    a cycle could be 100%-50% -100%-50% or 100%-0% if you see what i mean,

    it is advisable to remove the battery when your at home and its not being used at all.
     
  3. Much Ado macrumors 68000

    Much Ado

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    Sep 7, 2006
    Location:
    UK
    #3
    ^ I thought that 50-0% was 'worse' for the battery than 100-50% :confused:
     
  4. netdog macrumors 603

    netdog

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    Feb 6, 2006
    Location:
    London
    #4
    You ought to drain it to 0% about once a month and then give it a long deep charge. It is actually very good for the battery.
     
  5. Aranince macrumors 65816

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    Apr 18, 2007
    Location:
    California
    #5
    That isn't advisable because it slows down the CPU.
     
  6. cupofjoe macrumors regular

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    Feb 23, 2008
    Location:
    Los Angeles, CA
    #6
    Where are hearing this information? I've heard it's actually pretty horrible for your computer to do that.
     
  7. MacDann macrumors 6502a

    MacDann

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    Can see the end of the Earth from here
    #7
    So many myths, so much misunderstanding...

    RTFM, folks, right here.

    :rolleyes:

    MacDann
     
  8. Luzzio thread starter macrumors regular

    Luzzio

    Joined:
    Feb 12, 2008
    Location:
    Malaysia
    #8
    I've already looked at that before but it didn't really answer my question, but the above posts did, so thanks again MR members.

    I'm obsessive about battery life, becoming sad when I notice a drop in battery capacity over the months from my ipod, hp, etc.
     
  9. motulist macrumors 601

    motulist

    Joined:
    Dec 2, 2003
    #9
    Bottom line: The more time your computer is being powered by the battery, the less capacity the battery will hold in the future.

    It doesn't really matter how long the intervals of time are before being reconnected to the power supply, all that matters is the total amount of time your battery has been powering your computer since you bought it.

    More battery time used = less amount of battery power that can be stored in the future.



    Technical detail: It's not really the amount of battery time used over its lifetime, it's really about the amount of battery *power* that's supplied over its lifetime. So if you run your machine off battery the battery for 200 one-hour intervals with the power settings on high energy, then your battery will be able to store much less capacity than if you used low energy settings over the same 200 one-hour periods.

    EDIT 1) All you could ever want to know about lithium ion batteries is right here:
    http://en.wikipedia.org/wiki/Lithium_ion_battery

    And especially see this section:
    http://en.wikipedia.org/wiki/Lithium_ion_battery#Guidelines_for_prolonging_Li-ion_battery_life


    EDIT 2) Calibrating your battery has nothing to do with its ability to retain good storage capacity. The Calibration process is only to calibrate the battery power METER. Meaning you need to calibrate so that your Mac tells you the correct battery time remaining. However, this will actually LESSEN the storage capacity of your battery because as I said before, the more electrons your battery send out to your Mac, the fewer of them it can hold in the future.
     
  10. Luzzio thread starter macrumors regular

    Luzzio

    Joined:
    Feb 12, 2008
    Location:
    Malaysia
    #10
    Much appreciated, Motulist :)

    Though the removing battery and stuffing into a fridge part is kind of... weird. Oh well.
     
  11. motulist macrumors 601

    motulist

    Joined:
    Dec 2, 2003
    #11
    You're welcome, glad to help.
     

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