MB and MBP power supplies?

Discussion in 'PowerPC Macs' started by Transeau, Jun 21, 2006.

  1. Transeau macrumors 6502a

    Transeau

    Joined:
    Jan 18, 2005
    Location:
    Alta Loma, CA
    #1
    Does anyone have any idea if there would be an adverse effect if you used the MB's power supply with a MBP?

    I use both my 13" and my 17" when I'm onsite and I don't really want to carry the extra weight.

    Thanks
     
  2. emw macrumors G4

    emw

    Joined:
    Aug 2, 2004
    #2
    Well, the MB's power supply is only 60W, vs 85W, so a potential issue would be that it wouldn't provide enough power to run or charge the system.

    I doubt the MBP would actually be damaged in any way (I wouldn't suggest using the MBP adapter for the MB).
     
  3. bbrosemer macrumors 6502a

    bbrosemer

    Joined:
    Jan 28, 2006
    #3
    Apple talked about this at some point I dont remeber when or where, but what they said is that it will run the computer however it wont charge the battery.
     
  4. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #4
    Why not? The power rating is the maximum sustained draw. It's not a constant. So the MBP adaptor should be fine on a MB as it will happily supply the 60W required (at most). The other way round is probably not a good idea as the MBP will probably atempt to draw more power than the MB adaptor can supply potentially damaging the adaptor.
     
  5. emw macrumors G4

    emw

    Joined:
    Aug 2, 2004
    #5
    Duh. :eek: I was thinking the other way around - that the adapter would provide more power than required and cause a problem. I should know better.
     
  6. bbrosemer macrumors 6502a

    bbrosemer

    Joined:
    Jan 28, 2006
    #6
    http://www.macworld.com/2006/05/firstlooks/macbookfaq/index.php that is the link and here is the part of the story: I already own a MacBook Pro—can I use the power supply that came with it on a MacBook?
    If you hold the two power supplies side by side, you’ll notice that the MacBook Pro’s is larger. That’s because the MacBook Pro uses an 85-watt power supply, while the MacBook uses a 60-watt power supply. Apple says you can use the more powerful, 85-watt power supply with a MacBook without any problems, and that in 80 percent to 90 percent of situations, you can use the MacBook’s power supply with the more-demanding MacBook Pro as well. If you’re really taxing the MacBook Pro’s processor with some heavy-duty work, the MacBook’s adapter will still be able to power the MacBook Pro—but it may not have any power left over to charge its battery. There that says it all.
     
  7. pinetec macrumors member

    pinetec

    Joined:
    Mar 21, 2006
    Location:
    Red Sox Nation
    #7
    The MBP adapter works fine with the MB. I lost my MB adapter in the airport less than a week after I purchased it. When I went to replace it they were not yet available. The reps at the store said the MBP would work fine because it would automatically drop down to the 60 that was need for the MB. I bought it and it works fine. I have since purchased a true MB adapter since it is much smaller.
     
  8. Makosuke macrumors 603

    Joined:
    Aug 15, 2001
    Location:
    The Cool Part of CA, USA
    #8
    Small computer on a large adapter is of course not a problem.

    But I've measured my MPB (17", admittedly) drawing over 70W when it wasn't even charging the battery. If there's a limiter in the MB 65W adapter, then it's ok--if the MPB tries to draw too much, it'll just cut out. If not, it could very well overheat and damage itself.

    I, personally, wouldn't try it. Even the proper 85W adapter gets darn toasty at those loads.
     

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