Will old school magsafe work with current 2011 MBP?

Discussion in 'MacBook Pro' started by rainking, Sep 6, 2011.

  1. rainking macrumors regular

    Joined:
    Aug 12, 2011
    Location:
    Johnson City, NY
    #1
    I think I like this style better. Will they work on the current MBP?

    [​IMG]

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  2. JacaByte macrumors 6502

    Joined:
    Dec 26, 2009
    #2
    The plugs will fit, but the power adaptors that sport that plug type are not as beefy as the newer onces. (Specifically the 2010 generation) This means one or more of three things will happen; your laptop will not charge as quickly, your power brick will heat up and self destruct, or your laptop will refuse to charge at all.
     
  3. fat jez macrumors 68000

    fat jez

    Joined:
    Jun 24, 2010
    Location:
    Glasgow, UK
    #3
    you missed the 4th option (which is what actually happens) - the MBP will draw power from the battery to make up any short fall in what it needs (although not sure what will happen if the battery is discharged).
     
  4. Salukipilot4590 macrumors 6502

    Salukipilot4590

    Joined:
    Mar 17, 2009
    Location:
    Los Angeles, CA
    #4
    Not going to lie....I have no idea why they changed the design.

    The current design has nearly pulled my MBP off my desk after tripping on the cord....(klutz I know)

    I thought that was the point of "MagSafe"
     
  5. Naimfan macrumors 601

    Naimfan

    Joined:
    Jan 15, 2003
    #5
    Yes, it'll work fine.
     
  6. jamisonbaines macrumors regular

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    Dec 14, 2007
    Location:
    CA
    #6
    Do you have any proof to this? I was led to believe as long as you use the same wattage as your computer was supplied with the function will be identical.
     
  7. AFPoster macrumors 65816

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    Jul 14, 2008
    Location:
    Charlotte, NC
    #7
    The older ones use a different wattage for charging than there newer ones do. It will work but not correctly and will cause damage to the battery.
     
  8. Naimfan macrumors 601

    Naimfan

    Joined:
    Jan 15, 2003
    #8
    How do you mean? For MBPs, there are 85 watt Magsafe adapters for 15"/17" and 60 watt Magsafes for 13". Those have not changed. Nor does Apple provide the older Magsafes for older MBPs, and, indeed, Apple list the current Magsafe adapters as direct replacements for the older ones.

    As for causing battery damage, that's not true according to Apple.

    The new ones almost certainly use different parts, etc., but that's progress.
     
  9. AFPoster macrumors 65816

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    Jul 14, 2008
    Location:
    Charlotte, NC
    #9
    I thought the old magsafe adapters were higher wattage. If that was the case you never use a higher wattage adapter to anything that doesn't take that amount of watts.

    Apple might have something built in the transformers to coexist with different ports to accept different watts as they do with volts (120/240).

    In theory though something with higher watts can't go down or up, same with volts. i.e. a US built X-BOX 360 has a transformer that can only handle 120volts, if you plug it into a Euro plug which is always 240 it will blow the charger instantly and sometimes the unit itself.
     
  10. Naimfan macrumors 601

    Naimfan

    Joined:
    Jan 15, 2003
    #10
    Um, no.

    You can use an 85 watt Mafsafe adapter with an Air, just as you can use a 45 watt Magsafe with a 17" MBP. In the former, the Air simply draws the power needed and much of the capacity of the 85 watt Magsafe is unused. In the latter, the MBP's battery won't charge quickly (if at all), and any shortfall in required power will be made up by the battery. But in neither case will the Magsafe damage the battery or the computer.

    The wattage specified on a Magsafe adapter is the maximum it is rated to constantly deliver--it DOES NOT automatically supply that wattage all the time. Rather, the Macbook's power management circuitry and software determine how much power is required and draws that from the battery and/or Magsafe.

    You are correct that you generally cannot mix and match supply voltages (from the wall, so to speak) without either a transformer or specialized equipment that is built to adapt to different voltages. Which, interestingly, the Magsafe adapters are--if you look on your Magsafe it will say "Input: 100-240V - 1.5A 50-60 Hz. Thus, it can handle an input voltage of between 100 and 240 volts, will show a maximum current draw of 1.5 amps, and can use either 50 Hz or 60 Hz alternating current (AC).
     
  11. AFPoster macrumors 65816

    Joined:
    Jul 14, 2008
    Location:
    Charlotte, NC
    #11
    I know the magsafe can handle different volts, most things made can these days have transformers that step up and down. Apple is different with there creation on how they handle volts / watts / ohms. I am looking at this on the perspective of how things should react not how Apple does them. My mistake especially since we're talking about an apple magsafe.
     
  12. Naimfan macrumors 601

    Naimfan

    Joined:
    Jan 15, 2003
    #12
    I'm curious as to why you thought a new Magsafe could damage an older battery, or vice-versa?
     

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