rMBP Battery Indicator Issue

Discussion in 'MacBook Pro' started by reRESERVEDMD, Jun 27, 2012.

  1. reRESERVEDMD macrumors member

    Jun 27, 2012

    I got a 2.3Ghz Retina MacBook Pro and have noticed that the battery indicator tells me (currently) I have 75% charge remaining. However, when I look into iStat widget, it tells me it's 72%.

    I opened System Information under 'Power' tab and divided the total capacity of the battery by what was left and it came out to 72% indicating that the iStat is indeed correct.

    Does anyone else have a similar problem? I just find it quite weird. I had to exchange the laptop once for batch of bad pixels on the screen. I really don't want to go to the store again and deal with setting up a new device if it's just a software glitch and not a battery issue.


  2. IceAero macrumors newbie

    Jun 15, 2010
    Working as intended it would seem. It reports 100% when it gets to around 97%. Maybe because the last 3% take so long to charge?

    I imagine this is either what they wanted, or it will be fixed soon.
  3. Auzburner macrumors 65816


    Apr 11, 2008
    Syracuse, NY - USA
    Hmm, I don't have this issue, but have you drained the battery to zero to "calibrate" the scale of battery level yet? Give that a try.
  4. asdad123 macrumors regular

    Jun 16, 2010
    It is because the battery is holding a larger charge than it is designed for so Apple's built in percentage is off of the designed capacity while iStat is what the full charge is.
  5. reRESERVEDMD thread starter macrumors member

    Jun 27, 2012
    I've only killed it once and charged it all the way. This will be the second time. It takes a while to drain this thing :p Calibration will have to wait to about tomorrow or so.

    However, I did notice that the difference between the two went from ~6% to 3% now. I guess it should settle down after a while.

    On another note, I've also noticed that the rubber gasket running between the glass and the aluminum has a gap between it and the aluminum in the upper left corner. I don't think it should make any difference since this thing is glued to the glass so no dust issues there. Just a little annoying hah. I'm definitely not gonna risk getting another one for such a small issue. This is the 3rd rMBP I got... The other two had dead pixels, including one, where if we pressed them on the screen, they would disappear...
  6. korbearus10 macrumors member

    Jun 27, 2012
    I've actually had this in my old 13" MBP. It's not a big deal and it never became a problem for me. And if it ever does becomes a problem in the future, you know you can always go back to the Apple Store.

    Also, I think you're fine with the discrepancy between the iStat and the charge % reading on the OS. I've had this on my 13" MBP, too, though I have yet to test this on my rMBP. I very much doubt there's a problem with the batteries.

    In conclusion (ughh, I hate that phrase), I think your rMBP is just fine.
  7. Queen6 macrumors 604


    Dec 11, 2008
    Flying over the rainforest at dawn - Priceless
    There is no need to calibrate these batteries, all you are doing is consuming cycles. The system just needs to be used on the battery every 4-6 weeks to keep the electrons flowing and prevent premature failure, down to 20% is more than enough.

    Following the old calibration routine on a new machine only fools you into thinking that you are doing some good, as the battery takes several cycles to reach optimal performance from new.
  8. GGJstudios macrumors Westmere


    May 16, 2008
    It's nothing to worry about. Battery readings are estimates, and not 100% accurate.
    The built-in batteries in the newer Mac unibody notebooks come pre-calibrated and do not require regular calibration like the removable batteries.
    That's not true. The battery can't hold a charge more than it's designed for.

    This should answer most, if not all, of your battery questions:
  9. frozi macrumors member

    Apr 22, 2012

    Sometimes I unplug my gf's MacBook and she gets pissed. " you just wasted a cycle/charge". I've read a few places that you have so many charges or cycles. Do you know anything about this?
  10. GGJstudios macrumors Westmere


    May 16, 2008
    If you need to run on battery, do so, but don't cycle a battery simply for the sake of cycling it. Read the BATTERY LIFESPAN section of the Battery FAQ I posted.
  11. TheMacBookPro macrumors 68020


    May 9, 2008
    The more cycles you pile on, the lower the battery capacity gets. It depletes pretty slowly though.
  12. reRESERVEDMD thread starter macrumors member

    Jun 27, 2012

    I charged the laptop all the way up last night and unplugged it. I came to use it today and the battery says I have 100% charge. iStat however states I'm at 96% but at the bottom instead of telling me how much time I have left, it only says "charged". The OS indicator indicated between 7-9 hours just browsing the web.

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