Extremely high battery consumption rate

Discussion in 'MacBook Pro' started by pavenger, Mar 11, 2010.

  1. pavenger macrumors regular

    Joined:
    Oct 13, 2008
    Location:
    Spokane, WA USA
    #1
    So I have a late 2008 MBP and the battery is draining WAY faster than it should. Coconut battery says that my battery capacity is at 93% and it only has 73 cycles... but the battery has only been lasting 3 hours at best with a full charge, but most typically, it only lasts 2 hours while using the 9400m GPU and at idle. I have reset the battery per apple's instructions 2 times now and I have reset the SMC multiple times. this is what the system profiler says about my power capacity and consumption:

    Model Information:
    Serial Number: 6N839TV313EB
    Manufacturer: SMP
    Device name: bq20z951
    Pack Lot Code: 0000
    PCB Lot Code: 0000
    Firmware Version: 002a
    Hardware Revision: 000a
    Cell Revision: 0100
    Charge Information:
    Charge remaining (mAh): 3522
    Fully charged: No
    Charging: No
    Full charge capacity (mAh): 4226
    Health Information:
    Cycle count: 72
    Condition: Normal
    Battery Installed: Yes
    Amperage (mA): -1449
    Voltage (mV): 11830

    Any suggestions on what to do? this all happened out of nowhere one day, I used to get a solid 5 hours on each charge a month ago and now this... any input is more than welcome. Thanks!
     
  2. miles01110 macrumors Core

    miles01110

    Joined:
    Jul 24, 2006
    Location:
    The Ivory Tower (I'm not coming down)
    #2
    Most of the time these threads are about user habits and not bad batteries. Are you doing something that's taking up a lot of CPU that you weren't doing a few months ago? Youtube? Flash? Something else?
     
  3. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #3
    Is there any history of higher than normal CPU usage?
     
  4. pavenger thread starter macrumors regular

    Joined:
    Oct 13, 2008
    Location:
    Spokane, WA USA
    #4
    No, not at all, i'm getting bad battery when it is idling with no applications running. and the activity monitor says that nothing is taking up CPU usage at all... Im pretty good about diagnosing these things, but I can't see a single thing that is taking up any of the CPU's resources
     
  5. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #5
    This is from the usual script but are you viewing All Processes?
     
  6. pavenger thread starter macrumors regular

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    Oct 13, 2008
    Location:
    Spokane, WA USA
    #6
    Yeah and everything is in the LOW single digits and occasionally the system UI server hits 10%, but thats very occasional. as in a couple times a minute.
     
  7. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #7
    You mention the SMC. Have you reset the PRAM as well?
     
  8. pavenger thread starter macrumors regular

    Joined:
    Oct 13, 2008
    Location:
    Spokane, WA USA
    #8
    I can't say for certain that I have reset the PRAM. I'll look into how apple says to do that. by any chance do you know what all that does to the computer?
     
  9. pavenger thread starter macrumors regular

    Joined:
    Oct 13, 2008
    Location:
    Spokane, WA USA
    #9
    Just reset the PRAM and it did nothing to the battery life. Im still getting an estimated 1:50 with 75% battery left.
     
  10. pavenger thread starter macrumors regular

    Joined:
    Oct 13, 2008
    Location:
    Spokane, WA USA
    #10
    Since my 1 year apple care has expired and i did not buy the 3 year, will apple just tell me to screw off if i call them?
     
  11. Eidorian macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #11
    The battery's have an independent one year warranty apart from the computer itself. They've been kind enough to replace the battery regardless if you have AppleCare in some cases.
     
  12. pavenger thread starter macrumors regular

    Joined:
    Oct 13, 2008
    Location:
    Spokane, WA USA
    #12
    Well if the batteries have a separate ONE year warranty then im still out of luck since my computer and battery is still almost a year and half old. I hate that im 300 miles from the nearest apple store so i'll just give apple care a call and see what they can do if anything after I get out of class
     
  13. Pax macrumors 6502a

    Joined:
    Dec 12, 2003
    #13
    I don't think there is anything wrong with your battery. The problem simply looks like the Mac is drawing too much power from the battery. -1449 mA is very high. and you're right, with a 4200 mAh battery you'll get 2.5-3 hours out of it.

    (sorry I'm not diagnosing your problem here - simply telling other readers so they can help)

    You've got a 15" I guess, I've got a 13" and the current draw is of mine -1100 in the following configuration
    - brightness at max
    - WiFi on
    - CPUs idle (5-10% according to Activity Monitor)

    You don't need much CPU load to increase the consumption. Fully loading 1 CPU (ie taking total load to 50-60%) gets me to -2100 mA. I would guess that a CPU load of even 20% would get your consumption up to -1449 mA.

    Sorry to go through the same things again
    - rogue processes (only taking up say 20% of your CPU every now and then)?
    - could it be using the discrete graphics card without you knowing it?
    - have you changed habits eg screen brightness?

    And 2 questions:-
    - what are your CPU temps? (it looks like your CPU is consuming say 300 mA or 3-4W more than it should, that's got to turn into heat)
    - what System Profiler figures do you get if you turn brightness down to 1 notch above minimum, turn off WiFi bluetooth and keyboard lighting, and run on the 9400? You should get down to -700-900 mA

    You definitely have a problem, but I don't think it's a battery or power supply problem. There's plenty of juice in your battery, something is stealing it too fast.
     

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