Battery fixed itself...?

Discussion in 'MacBook' started by pmontanarella, Nov 3, 2012.

  1. pmontanarella macrumors 6502

    Oct 12, 2012
    Vancouver, Canada
    Hi all,

    I have a Late 2008 Aluminum MacBook. About 2/3 weeks ago I got the "Service Battery" message and the battery lasted between 30 minutes to as low as 10 minutes (and the battery indicator seemed broken, like the Mac shut off when it said 50% and wouldn't boot up again...). Now it seems that everything is back in working order and the battery lasts again around 1 hour/1 hour and a half. Also the battery indicator seems to work and the "Service Battery" message is gone. I haven't changed anything to it. I didn't have it serviced by a Genius. It just seems like it fixed itself. Does anyone know if that is possible? Why it would happen? And do you think my battery is in good shape again (I can use it)?

    Thanks in advance,
  2. Brian Y macrumors 68040

    Oct 21, 2012
    Well if it lasts 1 and a half hours its not great!

    Batteries can fluctuate due to either software problems, or chemical instability.
  3. pmontanarella thread starter macrumors 6502

    Oct 12, 2012
    Vancouver, Canada
    Well, it's pretty good if it used to last 4/4.5 when new and it's 4 years old...
  4. soapsudz macrumors member

    May 14, 2011
    You can download iStat or CoconutBattery to find out the battery health percentage. I think the "Service battery" indicator only shows up when the battery can hold less than 80% of the original charge.

    The 2008 aluminium Macbook as a max cycle count of 500, according to this:

    You can also calibrate the battery so the system knows the total charge available: It doesn't get you more battery life, it just improves the accuracy of the battery life indicator.

    My mid-2010 white Macbook can hold 77% of the original charge after more than 2 years and 450 cycles. Not bad, but not great, and I don't know how much a replacement battery costs.
  5. Brian Y macrumors 68040

    Oct 21, 2012
    If it's under AppleCare - they'll replace that for you. Those are designed to hold 80% after 1000 cycles.
  6. GGJstudios macrumors Westmere


    May 16, 2008
    One reason for the "Service Battery" indicator is that your battery health has dropped below 75%. As battery health fluctuates up and down over time, it's possible that it's below 75% sometimes and above it others. If it moves above it, that would explain why your "Service Battery" indicator goes off.

    Use iStat Pro (free) or iStat Menus ($16) to get accurate readings of your battery health, temps, fan speeds and much more.

    Try resetting the SMC and calibrate your battery using the steps in the CALIBRATION section of the Battery FAQ, linked below.

    The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
    AppleCare only covers batteries if they are defective. It does not cover replacement for batteries that have been consumed through normal use. The OP's battery is designed to retain 80% health up to 500 cycles, not 1000.

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