MBP Power Adapter - Interchangeable across MBP/MBA?

Discussion in 'MacBook Pro' started by GrassHoppa10, May 21, 2012.

  1. GrassHoppa10 macrumors member

    May 8, 2009
    Always wondered this.

    I have a MBP 15" Late 2011, MBP 13" Late 2011, and also MBA 13" 2011.

    Can the 85W power adapter from the MBP 15" be used to also power the other 2 machines?

    I ask because, my MBP 15" is from work - and when I use it at home several days a week, I have tie-wrapped the 85W adapter onto some existing cables for cleanliness - making the removal of for daily outside use not possible. Meaning I would like to use the same MagSafe power adapter to charge/use all 3 MacBooks when I move from one to another - without whipping out a dedicated power adapter.

    No risk of damage due to TOO much power? No risk to battery overcharge due to higher power adapter.
  2. simsaladimbamba

    Nov 28, 2010
    It will be okay. I did it myself countless times between 15" and 17" MBP and 13" MB.


    Maybe have a look at Advanced Search or MRoogle to find similar threads while you wait, for more confirmation:
  3. samac92 macrumors 6502a

    Feb 18, 2008
    Yep it's fine to use the higher power charger for lower power Macs, but you shouldn't use the lower power chargers on higher power Macs.

    The thunderbolt display has an 85W charger for use with all portable Macs
  4. kockgunner macrumors 68000


    Sep 24, 2007
    Vancouver, Canada
    If there a reason for this? I tried it once using an 11" MBA charger with a 15" MBP and besides it taking almost twice as long to charge, nothing went wrong.
  5. samac92 macrumors 6502a

    Feb 18, 2008
    I don't know about the specifics, but as far as I know it can cause problems.

  6. biohead macrumors 6502

    Jun 18, 2010
    West Drayton, UK
    MBP charger (the 85w version) is fine to be used on any MacBook model.

    For those wondering about the MBA charger on an MBP:

    If you use a 45w charger (MBA) for the MBP, which will pull around 75-80w at full load, you're stressing that charger massively - almost double what it should be.

    You'll notice it in two ways:
    1: The charger will be extremely hot (although the failsafes should kick in, which turn the charger off when its too hot)
    2: Your battery percentage will be decreasing - simply because the charger doesn't provide enough power and so takes the extra from the battery.

    The MBA charger will have a much reduced lifespan if it's being used on an MBP. Although it's not as much as an issue on the 13" MBP (which draws around 60w under full load).
  7. GrassHoppa10 thread starter macrumors member

    May 8, 2009
    Thanks everyone.

    I bought a extra 85W power adapter today, to cover all my travel needs, including office use.

    I plan to use it on all my MacBooks.

Share This Page