MacBook battery life...

Discussion in 'MacBook Pro' started by dex22, Jun 22, 2007.

  1. dex22 macrumors regular

    Joined:
    Jun 17, 2003
    Location:
    Round Rock, TX
    #1
    I've seen lots of MacBook battery life questions, and I came into possession of one recently, so I kept a log, which I'm publishing now for your amusement.

    iBook 2GHz C2D with 4GB (3.3GB available) and 160GB HD. All usage was general wireless surfing and IMing... All figures were running the battery down to shut-off point.

    15 cycles:

    Default:
    3h 22m
    4h 12m
    4h 08m
    Turned off bluetooth, switched from 1GB to 4GB:
    4h 30m
    4h 19m
    Made custom profile for screensaving and powersaving (basically, never shut off, make screen go dark in one hour) Also, at this time, I calibrated the battery, by letting it run flat, then leaving the macbook until the battery was COMPLETELY dead (took 16 hours) then gave it a full charge and left it for 8 hours trickle charging once completely full.
    4h 55m
    5h 12m
    4h 48m
    5h 01m
    Then I started dimming the screen. I often use my laptop in low light or well shaded areas, so I would set the screen to a comfortable medium setting.
    5h 46m
    5h 35m
    5h 37m
    5h 26m
    Then on the dimmest setting (2nd lowest)
    6h 52m
    6h 59m

    This is not using iTunes, or any DVDs, but may have included watching 1 or 2 youtube videos.

    In summary, turning devices off that you do not use does help, but the greatest saving comes from the double-whammy of dimming your screen and not doing anything processor intensive.

    I'm currently on battery for 2h 10m and have 4:10 remaining (66%)

    I hope the above figures are useful to anyone else curious about battery life on the current MacBooks.
     
  2. Sanderr macrumors regular

    Joined:
    Jun 14, 2007
    #2
    nice to see it can get up to 7 hours of battery live! Can't wait to get mine this week:) Is the screen readable well at lowest backlighting setting?
     
  3. mattscott306 macrumors 68040

    mattscott306

    Joined:
    Jan 16, 2007
    #3
    Um... how did you upgrade to four gigs? Macbooks only support up to 2 gigs of memory...
     
  4. flopticalcube macrumors G4

    flopticalcube

    Joined:
    Sep 7, 2006
    Location:
    In the velcro closure of America's Hat
    #4
    Only officially. Unofficially they can fully support 3GB and can even take 4GB but only use 3.3GB
     
  5. mattscott306 macrumors 68040

    mattscott306

    Joined:
    Jan 16, 2007
    #5
    I haven't heard anything about that, will you mind posting an about this mac screencapture?
     
  6. dex22 thread starter macrumors regular

    Joined:
    Jun 17, 2003
    Location:
    Round Rock, TX
    #6
    MacBook C2Ds all support 3GBs of memory. Apple only claims 2GBs. I went for 2x2GB SODIMMS instead of 1x1GB and 1x2GB so they would still be a matched pair. In "About this computer" it says 3.3GB.

    On the lowest setting for screen brightness, the screen is unreadable outdoors, and quite unpleasant indoors if you're near window light. If, however, you're in lower artificial light, or good shade, after a minute or two, your eyes adjust and it becomes quite comfortable. At night, it's quite usable.
     
  7. Sanderr macrumors regular

    Joined:
    Jun 14, 2007
    #7
    ok, then battery life will be well above my expectations..

    I read somewhere that running 4 gigs of ram enables 128 bit memory mode or something. And of course you're running in dual channel. I think on barefeats they did a test with C2D MB's with all kinds of memory configurations.
     
  8. flopticalcube macrumors G4

    flopticalcube

    Joined:
    Sep 7, 2006
    Location:
    In the velcro closure of America's Hat
  9. segfaultdotorg macrumors regular

    Joined:
    Jan 25, 2007
    #9
    Just a heads-up--you know that habitually deep-cycling the battery will reduce its lifespan, right? I'd only intentionally run it down completely every few months (or 30 cycles) to recalibrate it.

    Batteryuniversity has a great primer on lithium-ion batteries.
     
  10. dex22 thread starter macrumors regular

    Joined:
    Jun 17, 2003
    Location:
    Round Rock, TX
    #10
    Yep. I worried about that a little bit. However, I just followed this usage pattern to examine the battery life and see how it would be after a couple of charge cycles - it just went from there.

    Normally, I buy a new battery every 18 months and keep the old one as a backup for extended road trips or location filming.
     
  11. CalBoy macrumors 604

    CalBoy

    Joined:
    May 21, 2007
    #11
    Forgive my ignorance, but what exactly is this, and what does it do?
     
  12. flopticalcube macrumors G4

    flopticalcube

    Joined:
    Sep 7, 2006
    Location:
    In the velcro closure of America's Hat
    #12
    http://en.wikipedia.org/wiki/Dual-channel_memory

    Particularly effective with the GMA950 GPU which shares the RAM with the CPU.
     

Share This Page