5 Replies Latest reply: Apr 11, 2011 8:12 PM by kostby
hopedog Level 1 Level 1 (0 points)
Battery Information:

Battery Installed: Yes
First low level warning: No
Full Charge Capacity (mAh): 5003
Remaining Capacity (mAh): 2279
Amperage (mA): -1290
Voltage (mV): 12237
Cycle Count: 5

I got this info from the sys profiler, and it looks like I should have enough mAh for a full charge capability but the battery is consistently charging less and less. Now the green light comes on the charger but the battery is only charged to 47%. When I first charged the new battery it went to 99%. But since then it continues to drop. Please help if you can.

macbook 13.3, Mac OS X (10.4.11)
  • kostby Level 4 Level 4 (2,615 points)
    Welcome to Apple Discussions.

    First, calibrate the battery:
    http://support.apple.com/kb/ht1490

    Then, reset the SMC:
    http://support.apple.com/kb/ht3964

    From the low cycle count, it appears that you have kept it plugged in most of the time. For optimum battery performance, the battery should be discharged periodically and then recharged.

    There is a lot of basic information on batteries including an iCal reminder available here: http://www.apple.com/batteries/
  • hopedog Level 1 Level 1 (0 points)
    Thanks. I tried the reset on the smc. I have used it plugged in most of the time because after the first charge after a complete discharge it only charged to 87% then it got progressively worse till now it will only charge to 47%.
    Thanks for the help and I hope this works.
  • kostby Level 4 Level 4 (2,615 points)
    The "% charge" or "runtime remaining" indicators in the menubar vary with system load, and are not always the best indicators of overall battery health.

    Specifics for notebook batteries: http://www.apple.com/batteries/notebooks.html

    Lithium ion batteries require multiple charge/discharge cycles to get the maximum capacity of your battery when it is new.

    You need to discharge the battery fully at least monthly, calibrate occasionally (especially if the computer quits unexpectedly while running on batteries), and reset the SMC occasionally.

    And, if the battery is more than 3 years old, you're probably due for a new battery anyway.
  • hopedog Level 1 Level 1 (0 points)
    Okay, just got done letting the battery charge for two days (after a full discharge). Green light came on, and it only show 46% charged. The battery is new.
    I already reset the smc prior to this discharge.
    Any help would be appreciated.
  • kostby Level 4 Level 4 (2,615 points)
    Have you tried running the full Apple Diagnostics from the discs that came with your computer?
    This might uncover a problem with the logic board.

    I'd say the next step would be an Apple Store or authorized service provider.

    There is likely some problem or combination of problems with
    1) the battery - bad cell or connector
    2) battery connector inside the computer
    3) charging circuitry inside the computer
    4) the external power supply or MagSafe connector