65 watt power inverter to an 85 watt MagSafe?

Discussion in 'MacBook Pro' started by Kingsly, Jan 12, 2007.

  1. Kingsly
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    macrumors 68040

    Kingsly

    #1
    ... Will something blow up or will it simply deliver 65 watts (no battery charge) to my MBP? I am going to Japan and would love some movies on the plane. ;)
     
  2. iW00t
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    iW00t

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    #2
    I once connected a 65W adapter to my MBP and it worked fine.

    But long term usage... nobody knows :cool:

    Power inverter may overheat and catch fire, but that's the worst I can think of. Any engineers on this thread?
     
  3. Kingsly
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    thread starter macrumors 68040

    Kingsly

    #3
    Not sure if that would be good on a plane... :eek: :D
     
  4. ventro
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    macrumors 6502a

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    Sep 23, 2006
    #4
    Can you connect an 85W magsafe to a macbook (non-pro)?
     
  5. jeremy.king
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    jeremy.king

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    #5
    Yes.
     
  6. jsw
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    jsw

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    #6
    I think the issue with the 65W one on an MBP is that it can't keep up with peak demand and so might not keep it charged. However, I've got a 65W one upstairs for my MB and have used it on occasion to charge (not while being used) my MBP, with no harmful effects.
     
  7. dorthyinoz
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    macrumors member

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    Oct 19, 2006
    #7
    im still trying to find a place to get a cheap magsafe cord as my lazy boy spliced mine:(
     
  8. Kingsly
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    thread starter macrumors 68040

    Kingsly

    #8
    The main thing I am wondering is if a 65watt inverter will:

    A) deliver 65 watts and not a drop more, thus forcing my 85 watt magsafe to run on 65 watts, or B) reacts adversely to a stronger current draw than it is capable of, either bursting into flames or, preferably, shutting down.
     
  9. Bunsen Burner
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    macrumors regular

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    Feb 10, 2006
    #9
    Rectifier.

    BB
     
  10. Kingsly
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    thread starter macrumors 68040

    Kingsly

    #10
    Inverter, often containing circuitry which includes a rectifier. ;)
     
  11. maverick808
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    maverick808

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  12. orangemacapple
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    macrumors 6502

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    #12

    does it charge the macbook faster suing the 85w power supply than it normally does using the 65w
     
  13. jsw
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    jsw

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    #13
    I haven't timed them, and so it might, but I didn't notice any particular difference (but, then again, I might not have - I tend to charge overnight). I do know that the 85W one is officially blessed for use on both, whereas the 65W one is officially just for the MB.
     
  14. orangemacapple
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    macrumors 6502

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    #14
    would you do that for me

    that would be something i'd really like to know. it might make it worth the $79 to charge it in half the time.
     
  15. Counterfit
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    macrumors G3

    Counterfit

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    #15
    This was a common question pre-MagSafe too. Using a lower rated adapter/inverter/whatever will simply supply less than necessary, so it will take longer to charge than if the supplied adapter/whatever was used. I suppose that in cases of extreme power usage, it might need to use the battery a bit too.
     
  16. camatt29
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    macrumors newbie

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    Oct 23, 2008
    #16
    85 w on my macbook

    my cord for my macbook broke so i purchased the 85 w for the pro it will not charge my laptop in any way if i plug it in the led stays green but will never change and charge my laptop. why is it doing this do i need to change any settings?
     

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