What exactly does calibrating a battery do?

Discussion in 'iPad' started by silverblack, Dec 19, 2010.

  1. silverblack macrumors 68030

    silverblack

    Joined:
    Nov 27, 2007
    #1
    To perform the so called battery calibration, one would completely discharge and then fully recharge a battery. When exactly is the purpose? My understand is...

    It makes the battery meter reads more accurately. That's it.
    It does not increase the charge availble per cycle.
    It does not recondition the battery to extend its lifetime.

    Any corrections?

    If the above is true, it won't bother with it. It's not worth the hassle.
     
  2. Stealthipad macrumors 68040

    Stealthipad

    Joined:
    Apr 30, 2010
    #2
    If you are not having any problems, I would just use your iPad and enjoy it!:eek:

    Charge it when you want and use it like there is no tomorrow!:)
     
  3. silverblack thread starter macrumors 68030

    silverblack

    Joined:
    Nov 27, 2007
    #3
    That's what I have been doing, but still want to know the answer.
     
  4. MaxBurn macrumors 65816

    MaxBurn

    Joined:
    Nov 25, 2010
    #4
    It just shows the software how much battery there really is, that's it. It's rather interesting when it is wrong and bounces around 15-20% for a pretty long time. It is rather nice to have an accurate battery meter so you can know if you have another half hour or if you need to stop now before it dies.
     
  5. yamabushi, Dec 19, 2010
    Last edited: Dec 19, 2010

    yamabushi macrumors 65816

    yamabushi

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    Oct 6, 2003
    #5
    Some battery designs can develop a "memory" at less than their full potential capacity. Conditioning helps to prevent this. Battery capacity will often very slowly degrade over time and many charge/discharge cycles. Some new batteries are more susceptible to developing a "memory" and thus losing much of their capacity prematurely. Better battery management software has reduced the threat of this occurring somewhat but it is still a good idea to fully discharge and fully charge your battery when it is brand new. Also, if you tend to use full recharges instead of quick partial charges over time as you use the product you will help to prolong the life of the battery. Much of this depends on the particular type of battery.
     
  6. miles01110 macrumors Core

    miles01110

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    Location:
    The Ivory Tower (I'm not coming down)
    #6
    Mostly it's just something the battery fanatics tell you to do so they sound important. In reality, batteries are all over the place in terms of cycle count/capacity remaining. I've had batteries last years with ~50 cycles and batteries that last years with over 500 cycles. On the other end of the spectrum, I've had batteries that die within 6 months "calibrating" regularly and batteries that follow a "normal" lifetime of degrading steadily over time.
     
  7. Dr McKay macrumors 68040

    Dr McKay

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    Aug 11, 2010
    Location:
    Kirkland
    #7
    Batteries suffer from something called 'battery memory'. This is caused by charging a device when it hasn't been fully depleted first. As a result the battery 'forgets' its own storage capacity, and this leads to shorter battery life between charges.

    To remedy this, on an iPad for example. Let it reach 0% battery, or just the point where it turns itself off. And then turn it back on again, you might get a few minutes out of it, before it shuts down again, when it does, turn it back on again. Keep doing this until the device refuses to show any signs of life when you are trying to turn it on.

    At this point, charge it fully and if your device was suffering from 'battery memory' you will notice an increase of lifetime between charges, as the device lasts as long as it was supposed to from manufacture.
     
  8. silverblack thread starter macrumors 68030

    silverblack

    Joined:
    Nov 27, 2007
    #8
    I thought this memory effect no longer applies to the iPad lithium polymer battery. Why are we bringing it up here?
     
  9. bbhegedus macrumors regular

    bbhegedus

    Joined:
    Aug 22, 2010
    #9
    The iPad uses a lithium-ion battery. In order to keep its battery life at its maximum capability you should charge it completely, then completely drain it down. This is to keep all the ions within the battery moving, when they arent used, they stop moving and decrease battery life.
     
  10. yamabushi, Dec 19, 2010
    Last edited: Dec 19, 2010

    yamabushi macrumors 65816

    yamabushi

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    Oct 6, 2003
    #10
    It is a lithium polymer battery in the iPad. They supposedly do not develop memory internal to the battery (some have noticed a memory effect of some kind if the battery is not conditioned). However, some battery management software can create a similar effect anyways. I do not know if the iPad has this flaw or not. Regardless, you should be aware that lithium polymer batteries have relatively fewer useful charge cycles in their lifespan. Also, they tend to lose maximum capacity faster over their lifespan compared to some other common designs. This means that it may be prudent to try to maximize the battery lifespan as much as possible unless you would rather just replace it sooner than be bothered to worry about it. If you plan to replace the iPad within a year or two it probably isn't worth worrying about.
     
  11. miles01110 macrumors Core

    miles01110

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    Location:
    The Ivory Tower (I'm not coming down)
    #11
    "Keeping the ions moving" is possibly the most idiotic justification for cycling a battery ever. Ions never stop moving. It's impossible. Unless Apple has found a way to violate several laws of physics (or more likely, they've just convinced their fanatics that they have).
     
  12. bbhegedus macrumors regular

    bbhegedus

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    Aug 22, 2010
    #12
    im sorry i meant the electrons *******. and this is straight from Apple's website
     
  13. silverblack thread starter macrumors 68030

    silverblack

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    Nov 27, 2007
    #13
    I don't know where on the website you quoted Apple from. But I found the following referring to iPad specifically:
    http://www.apple.com/batteries/ipad.html

    For proper reporting of the battery’s state of charge, be sure to go through at least one charge cycle per month (charging the battery to 100% and then completely running it down).

    Again, this is strictly for the battery meter, and none of the nonsense about keeping whatever moving for conditioning of the battery.
     

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