Power Adapter Question

Discussion in 'MacBook Air' started by Eric5273, Apr 13, 2009.

  1. Eric5273 macrumors 6502

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    Apr 12, 2009
    Location:
    New Jersey
    #1
    I was wondering if the different power adapters for the different Macbooks are compatible with eachother even though they are different sizes.

    Specifically, I just purchased a Macbook Air. About once a month I visit family for the weekend, and they have a Macbook Pro. Can I leave my Macbook Air power adapter at home and simply use their Macbook Pro power adapter to charge my Air?

    I am aware about the difference in the end of the magsafe plug, but if I boost my Air up on a book I could easily use the Macbook Pro adapter to charge my Air. I just want to know if its compatible or if it will cause any damage.
     
  2. IgnatiusTheKing macrumors 68040

    IgnatiusTheKing

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    #2
    I've used the MBA plug on a regular MacBook and a MacBook Pro with no issues.
     
  3. aaquib macrumors 65816

    aaquib

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    Sep 11, 2007
    Location:
    Toronto, Canada
    #3
    Yep, you can use the MacBook or MacBook Pro adapters just fine with the MacBook Air. Just know, that because of the way the MacBook Air is designed, the Magsafe's for the other notebooks will be on a very steep angle, making it near impossible to have the MBA lying flat, connected to the Magsafe.
     
  4. SnowLeopard2008 macrumors 604

    SnowLeopard2008

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    Silicon Valley
    #4
    You can cross-use power adaptors but if you use a higher-watt adaptor on a lower-watt receiving end, things might be a little warmer near the power port.
     
  5. Eric5273 thread starter macrumors 6502

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    Apr 12, 2009
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    New Jersey
    #5
    Will this "little warmer" issue cause any sort of problems?

    I don't plan to use the computer while it's plugged into the Macbook Pro adapter. I only plan to use the Macbook Pro adapter to recharge the Air when it's turned off. Does this make a difference?

    While it would certainly be a convenience, I don't want to do anything that will cause any issues for my Air. Just from reading this forum, it seems as if the Air has enough issues to contend with on its own.
     
  6. dvdhsu macrumors 6502a

    dvdhsu

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    Mar 28, 2008
    Location:
    Palo Alto, CA
    #6
    It will not cause any issues.
    However, using a MacBook Air adapter with a MacBook (Pro) will cause problems, as there isn't enough power to support the computer.
    Same with using a MacBook adapter with a MacBook Pro.
     
  7. IgnatiusTheKing macrumors 68040

    IgnatiusTheKing

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    #7
    Can you clarify "issues" please? I've used my MBA's adapter with an older model MBP with a bad battery (that wouldn't hold a charge) and it kept it awake and working for about 45 minutes. When not plugged in, said MBP dies within five minutes.
     
  8. rhyx macrumors 6502

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    Jan 15, 2008
    #8
    I've heard using a MacBook power brick with a MacBook Pro will keep it running but not charge the battery.
     
  9. stoconnell macrumors 6502

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    Mar 22, 2009
    Location:
    Rockville (Despite REM's plea.)
    #9
    I just helped one of my co-workers discover that he was given a 60W power supply for his MacBook Pro rather than an 85W PS. He was complaining about needing a new battery because it wasn't charging; however, the battery was still in good health. When he'd plug in the laptop it would give ridiculously long times until the battery would be charged and then fail and say "battery not charging".
     
  10. dudeitsjay macrumors regular

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    Mar 26, 2009
    #10
    Then in theory, can upgrading the stock MBA 45w powersquare to say the 60w make the battery charge faster? :D
     
  11. stoconnell macrumors 6502

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    Mar 22, 2009
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    Rockville (Despite REM's plea.)
    #11
    Well, unless there is a input regulator. In my co-workers case, he was trying to run a laptop and charge a battery with 60W where 85W was the design supply. I dunno. I have an 85W PS here from my MBP, I could see if it changes the time to charge.
     
  12. LeeTom macrumors 68000

    LeeTom

    Joined:
    May 31, 2004
    #12
    An older MacBook Pro requires more power than a MacBook Air's power adapter will give it. If you've only had a bad battery since you started using a MBA power adapter, you may find the battery mysteriously recovers when plugged in using a MacBook Pro power adapter. It will give it enough power to both run AND charge.
     
  13. IgnatiusTheKing macrumors 68040

    IgnatiusTheKing

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    #13
    Interesting. The battery was never properly calibrated and hasn't held a charge for a long, long time. That being said, however, the MBA adapter did work well enough to power the machine on the couple of occasions I needed it to. Since the battery wasn't working correctly anyway, I'll take your word for it on the charging issues. We never tried to charge the MBP with the MBA adapter anyway (since it was pointless to try to charge a dead battery), just used it for power. Regardless, that MBP has since been replaced by a new model.
     
  14. aleksandra. macrumors 6502a

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  15. macuser154 macrumors 6502

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    Jan 17, 2009
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    UK
    #15
    It is worth noting that the Air's power adapter is 45W, and the Pro's adapter is 85W. I don't know if this makes a difference or not though.

    EDIT: Oh sorry, I didn't realise that someone has already said that.
     
  16. macuser154 macrumors 6502

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    Jan 17, 2009
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    UK
    #16
    What is the problem with bringing your adapter to your parents home anyway?
     
  17. Eric5273 thread starter macrumors 6502

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    Apr 12, 2009
    Location:
    New Jersey
    #17
    It's no huge problem. I was just being lazy and didn't want to bring it if I didn't have to. But it looks like there are potential issues if I use the Pro adapter on the Air, so I will bring my adapter with me. :)
     
  18. marina330 macrumors newbie

    Joined:
    May 11, 2009
    #18
    Just look at the volts and amps on your laptop(on the bottom) and look at the same on the power supply if they are within 10% then it's OK.
     

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