Previous generation power supply with 2011 MBP?

Discussion in 'MacBook Pro' started by Tomb01, Mar 11, 2011.

  1. Tomb01 macrumors 6502

    Joined:
    Jan 6, 2009
    Location:
    Colleyville, TX
    #1
    Got my new 2011 17" 2.3 MBP yesterday. Spent the day setting it up and migrating from my 2009 (migration assistant seems to have worked, but a couple of differences have appeared). Now am using it with the power supply from my old system, the light stays on yellow and the MBP shows 'calculating' for the battery.... Is the new MBP not compatible with the older power supplies?
     
  2. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #2
    What 2009 MBP did you have? It should work but if you had a smaller one, then it may not be able to provide enough power which might cause this issue.
     
  3. seb-opp macrumors 6502

    Joined:
    Nov 16, 2008
    Location:
    London/Norwich
    #3
    if the power supply is from a 15 or 17" it should work, 13" power supplies wont charge the battery as they don't supply enough power (60 watts for 13" vs 85 watts for 15" & 17")
     
  4. tylerpenn macrumors newbie

    Joined:
    Jan 17, 2011
    #4
    I'm using my 2006 15" MBP power supply on my new 2011 15" with no issues
     
  5. Tomb01 thread starter macrumors 6502

    Joined:
    Jan 6, 2009
    Location:
    Colleyville, TX
    #5
    The 17" C2D. Both power supplies are labeled '85w Magsafe'. The old one has the straight end, the new one has the 90 degree connection (like my wife's Macbook Air). Just shifted to the new power supply, and it is showing a green light, but the battery display is going back and forth between 'calculating' and 'charged', and the light is going back and forth between green and amber.


    Sigh....
     
  6. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #6
    The 60 watt chargers will work on the 15" and 17" MBPs. They just take longer to charge.
    Why are you using the old adapter, when your new MBP came with its own? Since you just got the MBP, you should reset the SMC and calibrate your battery, using the adapter that came with it. This should answer most, if not all, of your battery questions:
     
  7. adnoh macrumors 6502a

    adnoh

    Joined:
    Nov 14, 2010
    #7
    Macs...they just work.
     
  8. Tomb01 thread starter macrumors 6502

    Joined:
    Jan 6, 2009
    Location:
    Colleyville, TX
    #8
    I am a frequent traveler, so the new power supply lives in my briefcase. I purchased a couple of extra 85w ones for my previous MBP, one of which lives next to my desk the other next to my easy chair. So I think what I am experiencing is documented in another thread, where the power supply is not actually adequate for the power needs of the system under any kind of stress. I have the BOINC utility running in the background, set at 75% of my cpu, which was fine with my previous MBP (though it did tend to get warm). When I needed something resource intensive, would kill it or sleep it. Migrating to the new machine, 75% is 6 of the 8 threads, so 6 BOINC processes fired up and the system could just barely keep up with that load on the 85w charger. Any time I did anything resource intensive (browsed to a site with any kind of streaming video, like CNN) the cpu cranked up and it started flickering back and forth between charged and charging as the system stopped charging and used the battery for heavy load processing. Have reduced the available cpu on the BOINC agent to 50%, and that has corrected the problem, though I am not certain I am happy with that answer.
     

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