Magsafe 60W vs 85W question

Discussion in 'MacBook Pro' started by jjmaximum, Mar 12, 2008.

  1. jjmaximum macrumors member

    Joined:
    Apr 8, 2004
    Location:
    Gainesville, FL
    #1
    I just got my new MBP with the 85W magsafe adapter. I am considering getting my daughter a MB off the refurb site but it comes with a 60W adapter.

    My question is will these adapters work (safely) on either computer or is there a real difference between them.

    I need to know because the MB is $999 and a spare adapter for my MBP is $79. If the adapters are not compatible, it would probably make more sense to buy a refurb MBP for $1299.

    TIA
     
  2. virtuatony macrumors regular

    Joined:
    Mar 9, 2008
    Location:
    Canada
    #2
    From what I understand the MB can use either one to charge, but it is not recommended to use the 60W with the MBP because it's not powerful enough.
     
  3. TEG macrumors 604

    TEG

    Joined:
    Jan 21, 2002
    Location:
    Langley, Washington
    #3
    I believe that you can use a higher wattage power supply on a lower wattage system, as the power supply can throttle down to the lower level. However, you cannot get full power from a lower wattage power supply on a higher wattage system. You may be able to run directly off of power, but I doubt that the battery will charge.

    TEG
     
  4. creator2456 macrumors 68000

    creator2456

    Joined:
    Jul 10, 2007
    Location:
    Chicago
    #4
    Ditto.

    I would get the MB and an extra 85W power supply so it can be used with either system.
     
  5. TBi macrumors 68030

    TBi

    Joined:
    Jul 26, 2005
    Location:
    Ireland
    #5
    You're right but the higher wattage supply doesn't throttle itself. It just delivers as much power as needed. 85W is just the max power it can output. The power supplied is determined by the laptop and how much current it needs at any one time.
     
  6. jjmaximum thread starter macrumors member

    Joined:
    Apr 8, 2004
    Location:
    Gainesville, FL
    #6
    Thanks for the responses.

    So if I understand correctly, the 60W would work on a MBP, but it would just charge the battery slower if it was plugged in and off, and wouldn't charge it at all if it was plugged in and on?
     
  7. pacmania1982 macrumors 6502a

    pacmania1982

    Joined:
    Nov 19, 2006
    Location:
    Birmingham, UK
    #7
    Yup - MacBook Pro works with either 60W or 85W power cords. My sister and I had to share one when my power cord died. I would say the charging speeds are marginally slower, but nothing really to moan about.

    Also - the MacBook works with the 85W and 60W, so its kinda handy having two :D

    pac
     
  8. jjmaximum thread starter macrumors member

    Joined:
    Apr 8, 2004
    Location:
    Gainesville, FL
    #8
    OK guys, thanks again. I just ordered the MB 2.2 for $999.
     

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