Battery Failure/Health Disappointment - What should we do?

Discussion in 'MacBook Air' started by prominence, Feb 12, 2008.

  1. macrumors regular

    Joined:
    Jan 31, 2008
    #1
    This is not a complaint about the AMOUNT of battery life. This is more so a complaint about the HEALTH of the battery within my MacBook Air.

    I bought my MBA on Sunday. Started out at 98% health. Charged to full and left on power for 2-3 hours as suggested by Apple manual on first startup. Then proceeded to drain it with normal use down to 3%, then plugged it in.

    It took about 5-6 hours to charge, which I hear is normal for the first time re-charge anyways.

    My issue is, I just did the SMU reset last night to be safe. My battery keeps fluctuating between 2:50 and 3:40 and 4:15. Is this normal?

    Also, the health dropped from 98% to 97%.

    Though I am a little disappointed about the battery health and battery life (my old 15 inch 1.8duo 2gig Vista Dell laptop got 6 hours last year and still gets around 4.5-5 now), I just want a healthy battery! I don't care about "time" per say, just a healthy battery!

    What all do you think I should do? It takes 2 hours or so to even get to speak with a Genius at the apple store around here, and I don't want to wait that long to hear him do an SMU reset then say "hold tight, apple has a solution coming in the future."

    I know I accepted this issue as an early adopter, but it's still frustrating.
     
  2. macrumors 65816

    ob81

    Joined:
    Jun 11, 2007
    Location:
    Virginia Beach
    #2
    If it gets dramatic, you can easily return it for a replacement battery. There are a lot of methods that Air users have come up with to condition their batteries on this forums as well.
     
  3. macrumors 6502

    Joined:
    Nov 29, 2007
    #3
    First of all, avoid draining your battery. Every time you completely drain it, it has a small but permanent impact on battery life. So always charge at the earliest convenience.

    But 98% or 97% is within tolerance for a brand-new battery. The software doesn't know your battery's original capacity, it just uses an average.

    And the fluctuation of battery life is absolutely normal as well. What you do on your computer directly influences power consumption, and thus longevity.

    Wait a few weeks. If your battery shows unusual wear by then, you should be able to get it replaced for free.
     
  4. macrumors regular

    dahcheet

    Joined:
    Feb 7, 2008
    Location:
    Harrisburg, PA
    #4
    When you say "completely drain" the batter do you mean taking it to under 10% when the "you're running on reserve" message appears or do you mean draining till it goes into "deep sleep"? I usually take my batter down to reserve power and then plug it back in because I have this paranoid fear of old batteries and their capacity memories. Am I hurting my battery?
     
  5. thread starter macrumors regular

    Joined:
    Jan 31, 2008
    #5
    This is completely contrary to what I've read everywhere else, where they say it is best to drain a battery to below 10% and then charge it, they say that if you plug it in whenever possible and don't drain it then you will ruin the lifespan and health of the battery.
     
  6. macrumors regular

    squaremon

    Joined:
    Jan 18, 2008
    #6
    mine mba battery health started at 97%. I've only unplug and use 2 times and the health is now 95%:( Does that mean my battery has a problem?
     
  7. thread starter macrumors regular

    Joined:
    Jan 31, 2008
    #7
    :-( I feel this will be the fate for all of us MBA users.
     
  8. macrumors 68040

    Cybergypsy

    Joined:
    May 16, 2006
    Location:
    Central Florida!
    #8
    The MBP are even worse....give it time.......
     
  9. macrumors 603

    NC MacGuy

    Joined:
    Feb 9, 2005
    Location:
    The good side of the grass.
    #9
    After 19 cycles mine was down to 93% health - but the usage time is good @ 3:45 - 4:30 hrs:mins. All in all, not really disappointing but worrisome nonetheless. My Air never topped the one time health of 97%. I've tried lots of stuff, lots. I've resigned myself to using it as is and if it goes south in a year or less taking it in for repair/replacement. I'm not convinced the software is doing a good job of reading mAh or charging times/health because of the fluctuations. Example; had battery at 96% health this a.m. and after working all day & battery going dry plugged in and health stated 90%!! Now it's reading 94%.... Go figure?? Noticed too that it charges to 75% rather quickly at 2 - 2.5 hrs then goes into trickle mode and that takes just as long to go the extra 25% as it did to go to 75%. There have been battery updates before and am hoping for one for the Air. My local geniuses aren't too geniusy and I try to fix things myself before going through one of their fiasco's.
     
  10. macrumors regular

    squaremon

    Joined:
    Jan 18, 2008
    #10
    It happened to me once that istat shows my battery health at 96% but went back up 97% after charged. But still, I got this air less than a week and health drop like that. just kinda worry:(
     
  11. macrumors 68000

    ctt1wbw

    Joined:
    Jan 17, 2008
    Location:
    Seaford VA
    #11
    I've had mine for a week and I've done three cycles on the battery. I let it drain completely empty the other night and plugged it in the next morning. It took about 3 hours to charge, and now my battery is registering 100%. When I first got it, it was registering 97 to 98%. I have not done the smu or pmu thingy yet.
     
  12. macrumors regular

    Joined:
    Feb 2, 2008
    #12

    I did the same. Mine would only last about two and a half hours when I got it, and eight hours to charge. I used the unit off the battery until it went to sleep , zero power, then left it alone unplugged for five hours, then charged it up. It now charges fully in two hours, forty five minutes, and lasts for four and a half hours.
     
  13. macrumors 68000

    ctt1wbw

    Joined:
    Jan 17, 2008
    Location:
    Seaford VA
    #13
    So far I'm so happy with my purchase. This is probably the nicest laptop I've ever owned. I loooove the fact that it's three pounds. That is so nice, and so easy on my shoulders.
     
  14. macrumors 6502

    Joined:
    Apr 24, 2006
    #14
    This is true for NiCd and NiMH rechargeable batteries like the ones you can buy in a store, or the ones that typically come with cheap consumer electronics.

    IT IS NOT TRUE for LiIon batteries like the ones in our laptops.

    LiIon batteries don't like deep discharge cycles. They'd rather be kept around half capacity. Obviously that's not practical in real world usage. The best way to treat your LiIon battery in the real world is to keep it mostly charged most of the time.

    Once a month or so you should still deep discharge your battery to ensure it stays properly calibrated, but frequent and unnecessary deep discharge cycles will reduce the life of your battery.
     
  15. macrumors 6502

    duffyanneal

    Joined:
    Feb 5, 2008
    Location:
    NYC
    #15
    The battery is warranted for a year so if you notice that run time has really dropped thru the floor you can get a replacement. Right now it is really hard to tell if the battery health meter is accurate. It seems to go up and down which if you think about it does not inspire one to trust the software/hardware reporting the health status. As far as run time fluctuating that is par for the course. The battery capacity is so low on the MBA that anything that requires moderate to heavy power will really cause a significant hit on the run time. So if you are just surfing the web using relatively little CPU the battery run time will look good. But if you venture to a heavy flash site that causes the CPU to go to 50% utilization or higher your run time will take a nose dive. You don't notice it as much on say a MB or MBP, because the battery capacity is so much higher. As soon as you leave the flash heavy site the CPU utilization will go down and your battery run time will go up. It's like a really bad roller coaster.
     
  16. macrumors regular

    Joined:
    Jun 9, 2007
    Location:
    Seattle, WA
    #16
    Until someone can really tell me what "battery health" even means, especially the change of a few percent, i wouldnt be too quick to point any blame here. I would guess that it would be related to non-linear voltage changes during charge or discharge. I dont believe it has the accuracy to really display anything better than 10% accuracy, but i could be wrong. Like any other battery, there is an operating range of voltage from 4.2VDC to 2.6VDC, and it drops as battery capacity is used. the drop between 4.2VDC and 3.99VDC is very rapid, and again the drop off past 3.5VDC is quite significant, and it normally flatens out around 3.7 volts on a gradual decent, depending on load.

    LiPoly is probably the most forgiving battery technologies, you can practically do whatever you want to it, without damage to its over all capacity. Anything you could potentially do to damage it is limited in hardware.

    What will damage a Li+/LiPo:

    1) discharge rates above specification (LiPo is usually limited to 2C discharge unless its a specialty battery. 2C = 2x total capacity discharge rate, which would be almost 10 amps!)

    2) overcharge above 4.2VDC volts or undercharge of 2.5VDC per cell (i think the MBA has two cells, divide the voltage). Apple seems to have their numbers down, as the low voltage cut off is about 3.4 volts per cell (this is where voltage drops off so rapidly that its almost unusable at that point).

    3) physical puncture (aka, boom!)

    4) overly excessive temperature (usually over 80C in temp)

    The type of charge cycle does not matter. A cycle is one complete discharge, or an aggregate of discharge. (aka, two discharges to two 50%'s, four to 25%)

    Leaving the battery on the charger forever and not discharging it fully every blue moon can effect the chemistry of the battery over time. It can never overcharge it, but the chemistry will become static. you really want to keep those electrons flowing.
     
  17. macrumors 603

    NC MacGuy

    Joined:
    Feb 9, 2005
    Location:
    The good side of the grass.
    #17
    In short, battery health is the amount of mAh's the battery will charge related to its 'new condition'. If a battery is rated at say 5000mAh and its health is 90% it would mean the battery can only recharge to 4500mAh's. The health declines over time and cycles.
     
  18. macrumors 6502

    Joined:
    Apr 23, 2006
    Location:
    Wales, UK
    #18
    My MBA battery health was at 96% yesterday, and today it is at 95%. Should I condition it? If so, how would I do the 'condition'?
     
  19. macrumors regular

    dahcheet

    Joined:
    Feb 7, 2008
    Location:
    Harrisburg, PA
    #19
    To condition your battery all you have to do is run it until it is out of juice. When the battery gets to 10% you'll get a warning saying you're on "reserve" power. Keep going until the computer puts itself into "deep sleep" (I think it's around 3% or less). Let the computer sit in "deep sleep" mode for 5 hours (as recommended by Apple). Best bet is to do this before you go to bed, obviously, so you don't need it while it's discharging those last electrons of power. After that, plug it in and let it charge.

    Of note, when doing this make sure that nothing important is open before it goes into "deep sleep". Your computer will make a backup of what was open and on the screen before it goes into "deep sleep" and SHOULD startup to that when you turn it back on, but it's always better to be safe than sorry.

    I did half of this process and but forgot to let it sit for 5 hours so I'm going to try this again tonight or this weekend. My current battery health is 96% after 11 cycles per iStat.
     
  20. macrumors 6502

    Joined:
    Apr 23, 2006
    Location:
    Wales, UK
    #20
    Cool, thanks for the reply. Should conditioning solve my problem?
     
  21. macrumors regular

    dahcheet

    Joined:
    Feb 7, 2008
    Location:
    Harrisburg, PA
    #21
    That's unknown. There have been a lot of "solutions" posted but nothing that solves specific things or works 100% of the time. It's really a case by case solution. Just give it a look when you've done the conditioning and see what the health looks like and go from there.
     
  22. macrumors 603

    NC MacGuy

    Joined:
    Feb 9, 2005
    Location:
    The good side of the grass.
    #22
    Just keep using it and cycle through standard charge cycles. I think that resetting PMU is being done way too much. Mines on 21 cycles now and I went crazy resetting, conditioning, obsessing for about 13 cycles. Finally just gave up and used it like normal and battery has been up to 97% for past 3 cycles and seems to keep getting a wee bit better as I use it.
     
  23. macrumors regular

    Joined:
    Jun 17, 2004
    #23
    ..

    I'm at 4832 for a max charge. Not great but not horrible, I suppose. The thing that bothers me is that I can't seem to get more than 3 hours of battery life. Sure, dimming it to 20% and not using it will get me 4 or 5 hours.

    However, normal websurfing, no music, no video, no bluetooth...and I'm struggling to get get 3 hours. What gives?!
     
  24. macrumors regular

    Joined:
    Jan 25, 2008
    #24
    where does one check this "battery life health"?
     
  25. macrumors newbie

    Joined:
    Feb 9, 2008
    #25
    ViperrepiV,

    I dowloaded a widget called Istat Pro. This widget will give you all sorts of info about your Mac including battery health.

    Good luck
    Rob
     

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