rMBP late '13 battery charging issue

Discussion in 'MacBook Pro' started by mTECx, Feb 14, 2014.

  1. mTECx macrumors newbie

    Feb 14, 2014
    Hi guys,

    I have an issue with my rMBP late 2013 battery. Basically after a couple hours of charging the charging cable light changes from orange to green (as one would expect) and on the top right it shows 100% and says "charged". However, when I go to System Information I can see that it hasn't reached the Full Charge Capacity and it says "charging". If I wait another 40 min. it will reach the full charge and say Fully charged. So that's more than half an hour after the light already turned green and after the battery indicator in the menu bar said it had been 100% charged.

    I already got my battery replaced when they replaced the whole top case of the laptop for another issue, and I'm still having the issue so it can't be the battery. I have reset the SMC as well to no avail.

    I'm assuming this isn't normal.. could anyone just confirm this isn't happening with their rMBP's? I really don't want to send it back to repair again since I need to use my laptop for work but I guess I will have no other choice.

    Thanks for your help :)
  2. durkkin macrumors regular

    Sep 23, 2013
    It actually is normal. The light will turn green around 99% and the menu bar will show it is fully charged and at 100%. The last stage of charging (from about 80% onward) is a trickle charge, and that last little bit takes exceptionally long.

    For the sake of argument, think about your battery like a bike tire. When the tire is flat it's very easy to pump air into it (similar to putting electricity into the battery). But as it gets closer to full and there is a significant amount of pressure in the tire, it's hard to squeeze more air into the tire. It gets to a point where it could store more air, but for all intents and purposes it's full. Same with your battery. Your computer tells you that it's fully charged, but really there is a bit more you could squeeze into it. It just takes an exceptionally long time, and if you're trying to go, it's not worth it to stick around for another 30 min.

    Ignore what the system report says. It is correct, but it's more useful to just go off of the light indicator.
  3. mTECx thread starter macrumors newbie

    Feb 14, 2014
    Thanks a lot for the explanation! Really glad I don't have to send it back :)
  4. GGJstudios macrumors Westmere


    May 16, 2008
    There's nothing wrong with your battery.Apple notebook batteries charge faster until they get closer to fully charged. Then the charging rate decreases and it charges more slowly until completely full. A full charge may be indicated as 98-99%, rather than 100%, and a less than 100% charge may be indicated as 100% because the battery readings are estimates, and not completely accurate. It's nothing to worry about.

    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.
  5. mTECx thread starter macrumors newbie

    Feb 14, 2014
    Just one more thing: you said it turns green at 99%, however my battery at that point has only charged about 6000 mAh of the 6428 mAh. Also I notice how it first says 40 min. left when charging and then it suddenly jumps to "Charged".

    Just want to be sure that this is the trickle charge and not an issue :)
  6. mTECx thread starter macrumors newbie

    Feb 14, 2014
    Not sure if I phrased my last post right, basically I wanted to ask how much of the full capacity mAh (6401 for me) is charged for other rMBP owners when the light turns green.

    For me that's only 92% charged when turning green, so that's a less than the 99% I'm reading about. This is also a brand new battery with only 4 cycles.

    So is this the trickle charge, or an actual issue with my battery? How much of your batteries are charged when the light turns green?

    Thanks a lot for your help again
  7. GGJstudios macrumors Westmere


    May 16, 2008
    There's not a fixed percentage at which the trickle charge starts. I wouldn't obsess about when the light turns green, as long as your battery is charging and holding sufficient charge to meet your needs.

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