8 Replies Latest reply: Dec 25, 2012 4:30 PM by Trane Francks
neesie192 Level 1 (0 points)

I  have noticed that my macbook wouldn't charge to it's full capacity anymore. It stops at 96% even when I charged it for ages, it still remains the same. It never used to happen like this before. I am running on mountain lion.

Anyone experience this?

MacBook, OS X Mountain Lion (10.8.2)
  • frederic1943 Level 6 (9,980 points)

    Go to the Apple in the upper left corner and select About This Mac, then click on More Info (and then System Report if you are running 10.7 Lion or 10.8 Mountain Lion), then select Power from the left hand column of the System Profiler. Copy and paste the Battery Information from the top of the page back here.

  • neesie192 Level 1 (0 points)

    Battery Information:


      Model Information:

      Serial Number:          W0020TR2UE1LA

      Manufacturer:          SMP

      Device Name:          bq20z451

      Pack Lot Code:          0

      PCB Lot Code:          0

      Firmware Version:          201

      Hardware Revision:          000a

      Cell Revision:          165

      Charge Information:

      Charge Remaining (mAh):          3832

      Fully Charged:          No

      Charging:          No

      Full Charge Capacity (mAh):          4989

      Health Information:

      Cycle Count:          147

      Condition:          Normal

      Battery Installed:          Yes

      Amperage (mA):          -1517

      Voltage (mV):          11563

  • Trane Francks Level 2 (230 points)

    If it occasionally doesn't go to 100%, that's normal behaviour. Batteries are constantly changing their state of operation and the circuitry that figures out how much charge it can take, etc. is sometimes just a bit off.




    If the battery never reaches 100% anymore, then you're a candidate for an SMC reset:




    After resetting the SMC, you might want to calibrate your battery again:



  • neesie192 Level 1 (0 points)

    I callibrated it and it charged to 99% now. Thanks for your help

  • LexSchellings Level 6 (8,774 points)

    neesie, it is explained somewhere in the Apple manuals.

    When you connect the charger when the battery shows 95% or higher, it will no further charge.

    When you put the charger in when, for example, the battery is at 85%, the charger will charger will not stop at 95% but continue charging till 100%.

  • neesie192 Level 1 (0 points)

    I noticed that the battery life is very bad. It doesn't last for long maybe 3 hours without the charger in :/

  • LexSchellings Level 6 (8,774 points)

    Your battery capacity is around 75% of the original capacity. So the lifetime of a charge is lower than when new. Your battery is still good according to your battery information ("condition; normal"). using it until it is around 50% and then charging is the best way to enjoy the battery as long as possible (this keeps "the electrons moving"). Do not do a complete "calibration" often: it resets only the electronics and not your battery, and subtracts a full cycle of the life of the battery.

  • Trane Francks Level 2 (230 points)

    The other aspect I'd add is that you want to use your battery at minimum of once per week. When it comes to batteries, "Use it or lose it."