Calibration kills Clock and Wireless

Discussion in 'MacBook Pro' started by Melodeath, Nov 26, 2011.

  1. Melodeath macrumors 6502a

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    Dec 9, 2009
    #1
    Last night I calibrated my battery (mid-2010 15" MBP) because I wanted to see the battery health. I had a bunch of programs open and working and an external hard drive plugged in to drain the battery. After an hour like this, the warning came up that the computer was running on reserve battery, I unplugged everything and closed all programs. The computer shut itself off (it looked off, not asleep) about 20 mins after that.

    When I plug the computer back in about 8 hours later, the computer automatically started up, but I get a warning that the clock is set prior to January 2008 so some programs may act erratically. In fact, the clock is set to December 31, 2000. And, my wi-fi password was forgotten. I put the wifi password back in and the clock was updated with the Apple server.

    The same thing happened before when I accidentally let my computer die, so I know this is a recurring issue. If the battery drains all the way, the system forgets the wifi passwords and the system clock is forgotten. Why is this happening? Is anyone else having this issue?

    Furthermore, my battery health is 89% with only 84 cycles. Seems bad to me.
     
  2. GGJstudios macrumors Westmere

    GGJstudios

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    #2
    First, your MBP comes pre-calibrated and does not require regular calibration. Second, your battery health will fluctuate up and down over time, so don't worry about it unless it drops below 80% before 1000 cycles. As for the clock reset issue, it's a common issue, which also happens if you reset NVRAM. You just have to reset your clock.

    This should answer most, if not all, of your battery questions:
     
  3. iThinkergoiMac macrumors 68030

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    #3
    Almost sounds like your PRAM battery is dead, but that should never happen in a computer about a year old.

    Also, running your computer down and charging it back up doesn't calibrate the battery. Apple has specific guidelines on how to do this.
     
  4. calderone macrumors 68040

    calderone

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    #4
    It actually all stems back to the clock and this isn't an issue.

    To keep time, you need power (like a watch and everything else). Most computers have a backup battery (typically a CR2032), Apple doesn't use a secondary battery in their portables namely because it has a battery and an external power source. They use to, but stopped with the unibody models.

    If you drain your battery completely, the computer has no power source to keep time thus things get reset.

    It isn't forgetting the passwords, but the modified dates on the keychain entries are in the future (there are probably other explanations as well, funny things happen with computers and time).

    The best way to handle this is to fix your time (even if you can't sync with Apple, set it manually). Then turn your Airport off and back on. Things should work as they did before.
     
  5. Melodeath thread starter macrumors 6502a

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    #5
    Hey guys, I know the battery doesn't need to be calibrated, and I don't do it often. I did it because I haven't done it in a year and I wanted an accurate reading of the "health," which before calibration said it was 97% healthy.

    I also didn't just run it down and re-charge it. I followed the guidelines outlined in this post: http://forums.macrumors.com/showpost.php?p=9875442&postcount=23

    Anyway, how is this clock issue acceptable? Forgetting the wifi passwords is quite annoying. Why wouldn't the computer keep enough power in reserve to make sure the clock stays correct? It seems it would be designed that way.

    How would I check if the PRAM is dead?
     
  6. iThinkergoiMac macrumors 68030

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    #6
    Looks like you posted while calderone was also posting. In case you're getting alerts, calerone's post should answer all those questions.

    And thanks to calderone, I didn't realize these computers didn't have a PRAM battery. Now that I think about it, I never saw one when I took apart mine to replace the LCD screen.
     
  7. GGJstudios macrumors Westmere

    GGJstudios

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    #7
    The NVRAM isn't dead. If it were, you wouldn't be able to set a date and time. By the way, it's not called PRAM. On Intel-based Macs it's NVRAM.
     
  8. Melodeath thread starter macrumors 6502a

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    #8
    So this is a common issue for anyone with an intel-based mac notebook? I'm surprised

    I'm going to want to calibrate every so often to get a more accurate reading on the battery health, but it makes me nervous when doing so messes with the system clock
     
  9. GGJstudios macrumors Westmere

    GGJstudios

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    #9
    As I already said, newer built-in batteries like yours don't require regular calibration. There is no need to frequently calibrate them.
     
  10. calderone macrumors 68040

    calderone

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    #10
    This is an issue for anyone who has ever owned a modern computer.

    If you are going to "calibrate" then you can expect to have this issue.
     
  11. GTANJ macrumors member

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    #11
    Why is this so?
     
  12. Melodeath thread starter macrumors 6502a

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    #12
    In your own FAQ you say "[Calibrating] does make battery condition reporting more accurate, so when your battery reports 97% health, it's more accurate. Without calibration, your battery health could be 60% but still being reported as 95%, for example." This is the info I was following, and indeed the health went down by 10% after this calibration. I've seen the health fluctuate, but never by more than 3%, and now it's down by 10%, so I think the calibration did make things more accurate. I don't calibrate it regularly, I did it merely to get a more accurate reading of the health

    Calderon, I'm surprised modern computers have this issue. Isn't there normally a CMOS battery ont he motherboard that saves things like the time?
     
  13. calderone, Nov 26, 2011
    Last edited: Nov 26, 2011

    calderone macrumors 68040

    calderone

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    #13
    Of course they do and for the same reason. A loss of power. If the CMOS battery dies and there is no other power then those settings are gone. So of course modern computers have this issue. If the issue is: A loss of settings due to complete power loss.

    The distinction here is that Unibody MacBook Pros do not have a secondary battery and thus if they are not connected to a power source and the internal battery dies, those settings are gone.
     
  14. Melodeath thread starter macrumors 6502a

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  15. iThinkergoiMac macrumors 68030

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    #15
    What CMOS battery? You've been informed multiple times that your MBP doesn't have one.

    The non-removable batteries are far more advanced than normal Li-Ion batteries. I don't presume to know the technology behind them, but they don't need calibration.
     
  16. GGJstudios macrumors Westmere

    GGJstudios

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    #16
    That is true. However, the very first sentence of the CALIBRATION section of the Battery FAQ states:
    If you follow the link in that quote, you will find:
     
  17. GTANJ macrumors member

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    #17
    I understand this. My question was, why is this so?
     
  18. Melodeath thread starter macrumors 6502a

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    #18
    Yeah. I guess I'm just surprised theres no CMOS or CMOS-like battery on the motherboard in the MBP to save these small things even after the main battery dies.

    Also, if you don't calibrate these newer MBPs, how are you supposed to know if your battery health is under 80%? The health reported doesn't seem to be very accurate unless you calibrate
     
  19. iThinkergoiMac macrumors 68030

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    #19
    They're already calibrated...
     
  20. Melodeath thread starter macrumors 6502a

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    #20
    Yes, I see on the apple site it says they are pre-calibrated and don't need to be calibrated, but as in the FAQ, calibrating can give more accurate health readings, which is what I'm interested in.
     
  21. iThinkergoiMac macrumors 68030

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    #21
    Also as in the FAQ, calibrating isn't necessary (ie, won't give you any more accurate readings).
     
  22. Queen6 macrumors 603

    Queen6

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    #22
    You are do nothing more than consuming battery cycles, just run the battery down below 20% every 4-6 weeks to keep the battery healthy, if the notebook is mostly used on the mains supply.
     
  23. Melodeath thread starter macrumors 6502a

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    #23
    iThinkergoiMac,

    I'm not getting you. That's a contradiction haha

    If the FAQ is wrong, that's fine, but the FAQ clearly states calibration is not necessary, but that it WILL give you more accurate battery health readings. I have no clue if that's true, as I don't know how these batteries or health sensors work, but my health reading changed a significant amount after following the calibration procedure, so I'm inclined to believe it.

    You're saying the FAQ is incorrect?
     
  24. GGJstudios macrumors Westmere

    GGJstudios

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    #24
    It is true that calibration's purpose is to make your battery readings more accurate. It is also true that newer built-in batteries do not require regular calibration to stay accurate. Even with a properly calibrated battery, the readings are less than 100% accurate, as they are only estimates. It is possible that occasional calibration of a newer battery may yield more accurate readings, but it's not required as it was with earlier batteries.
     

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