Battery calibration: trying to kill it?

Discussion in 'MacBook Air' started by Mhaddy, Mar 17, 2008.

  1. Mhaddy macrumors 6502

    Mhaddy

    Joined:
    Oct 26, 2005
    Location:
    Canada
    #1
    I'm in the midst of following the calibration how-to on Apple's website, and I'm curious: on step 3 when it says to use battery power and drain the battery, are we supposed to try to prolong the life of the battery (e.g., dim screen, turn off keyboard backlighting, use minimal apps, etc.) so that the battery "remembers" that it was alive for a long time, or should we turn on full brightness, use lots of apps, watch movies, etc. to kill it quickly so as to move onto steps 4-6?

    Thanks!
     
  2. Alkiera macrumors regular

    Joined:
    Mar 11, 2008
    #2
    I don't think the speed at which you drain the battery matters. All those things adjust the power usage, which it takes into account when calculating time-to-charge/time-to-die. MiniBatteryLogger will display the current draw on the battery if on battery, and the current being pushed from the charger, when charging. You should be able to see the change in current draw with the screen/kb backlights on full and CPUs cranked up vs. with the screen dim and CPUs idling.
     
  3. kockgunner macrumors 68000

    kockgunner

    Joined:
    Sep 24, 2007
    Location:
    Vancouver, Canada
    #3
    i think ur supposed to use it how you would use it normally.
     
  4. NC MacGuy macrumors 603

    NC MacGuy

    Joined:
    Feb 9, 2005
    Location:
    The good side of the grass.
    #4
    It depends on what time of night it is:D I've done it both ways and I don't think it matters. The idea is to find zero.

    I do think you are supposed to let it rest for at least five hours from shutdown before recharging to full.
     
  5. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #5
    The battery doesn't remember anything. If I were you just speed up the depletion as much as you can.
     
  6. Mhaddy thread starter macrumors 6502

    Mhaddy

    Joined:
    Oct 26, 2005
    Location:
    Canada
    #6
    Hmmm... now I'm concerned. I followed Apple's instructions, and on step 5 I let it sleep for more than 5 hours and now on step 6, it's been plugged in for more than 8 hours and when I awoke it from sleep this morning, the amber charge light was still on! I opened the lid and the battery charge meter said ~2 hours to full charge.

    This probably the 3rd or 4th battery charge on a week 10 MBA, though it's only the second from a full "dead" battery state. I know the first few charges are supposed to take a while, but I think ~10 hours is a little ridiculous. Has anyone else tried the battery calibration and ran into this problem?
     
  7. Alkiera macrumors regular

    Joined:
    Mar 11, 2008
    #7
    My first charge after calibration also took FOREVER. The 10-12 hours isn't out of the realm of possibility. Since then, it's much faster; 2-4 hours, depending on just how deep I drained it. And the last 25% or so is always slower, since it switches to trickle-charge.

    I have a week 7 MBA.
     
  8. NC MacGuy macrumors 603

    NC MacGuy

    Joined:
    Feb 9, 2005
    Location:
    The good side of the grass.
    #8
    Just let it charge all the way before unplugging. Mine was a bit spastic too it seems like the first week. The first charges seemed to take forever (8-11hr.)

    Now after 51 cycles it takes 2 hrs. to charge from 0-80% and another 2 hrs. from 80-100%. Been that way for last month.
     
  9. ayeying macrumors 601

    ayeying

    Joined:
    Dec 5, 2007
    Location:
    Yay Area, CA
    #9
    I never did a calibration and my battery charges from 5%-80% in about 2 hours, then another 1.5-2 hours for the last 80% - 100%.
     

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