Charge MBA with iPhone charger while traveling theoretically possible?

Discussion in 'MacBook Air' started by Sandoranges, Mar 1, 2014.

  1. Sandoranges macrumors newbie

    Joined:
    May 31, 2013
    #1
    Hey,

    I know you can't charge MBA today with an iOS charger.

    BUT, could it be possible technically (considered the difference in wattage and voltage) to charge it, through an USB port or a lightening-port while on-the-go?


    Now that the MBAs battery is so good, it would be very nice to leave the regular charger at home for weekend-travels, charge the MBA overnight with a small charger at your hotel and use it all day.


    So could this be something that could be done, or does the MBA battery have to be charged with its specific voltage?
     
  2. ha1o2surfer macrumors 6502

    Joined:
    Sep 24, 2013
    #2
    That would be nice, my Dell venue Pro 8 can do that.

    The Apple chargers I think supply dual voltages at a much higher voltage than 5 volts with is USB. A battery that size that can be charged with 5 volts but it would take a lot longer than a night plugged in... so I'd say it's impossible.
     
  3. Mrbobb macrumors 601

    Joined:
    Aug 27, 2012
    #3
    Anything is possible if u spend enough time on it and the end product end up as big, take as much space as the MBA charger.

    Voltage: IOS puts out 5v, MBA wants like 10(?) volts. So u need some kind of up-converter (yes another thing to carry). If you are going to do that, may as well try to find a smallish 10v plug to begin with.

    Wattage: Here is the bigger problem. More wattage means bigger unit. So OK you say you don't mind having it plugged in overnight. The supply has to have current limiting capability. MBA will attempt to suck all the wattage it needs and if the supply doesn't have current limiting, it will heat up big time and BURN.

    If you are successful doing this, and it works, I don't know what's the long term consequence to the health of the battery.

    All in all, sounds like more trouble than it's worth to satisfy your curiosity.
     
  4. ha1o2surfer, Mar 1, 2014
    Last edited: Mar 1, 2014

    ha1o2surfer macrumors 6502

    Joined:
    Sep 24, 2013
    #4
    it actually needs 16.5 volts. So you will need a 5 volt adapter that can supply quite a lot of amps so it can output 16.5 volts at around 4 amps. The same reason why an inverter needs to pull hundreds of amps from a cars alternator to supply 100 watts at 120 volts. I doubt you'll find something that can supply 5 volts at a very large amperage that's smaller than the magsafe. so you're right but it wouldn't be very efficient at all or worth the effort.

    I could be wrong but in order to boost DC 5v to DC 16.5v at 4 amps for the air, you'll need a 5v supply that can deliver 26amps. You will be looking at some pretty thick cables too at that point. The iPad charger can do, at most , 2 amps. so again, I think I'll stick with my impossible theory (that he could use an iphone/ipad charger to charge his air)
     
  5. Sandoranges thread starter macrumors newbie

    Joined:
    May 31, 2013
    #5
    Yes, it would probably be difficult.

    Not thinking of doing anything myself actually, just think the MBA is so thin now, that for Apple to sell a slower-charging but smaller "Travel/school/work"-charger would be more attractive for me than reduce the thickness of the machine itself.
     
  6. Flynnstone macrumors 65816

    Flynnstone

    Joined:
    Feb 25, 2003
    Location:
    Cold beer land
    #6
    I'd its possible on a future design , but HIGHLY unlikely.
    I don't think it makes sense.

    Look at the physical size of an iPhone charger, then look an iPad charger, then a MBA charger. The size is a rough estimate of power capability.
    These chargers do voltage conversion from 100-250 VAC to 5 Volts for iPhone & iPad and mid-teens voltage for MBA. My MacBook charger is 16.5V at 3.65 Amps.
    So … to go from a 5V iPad charger to a 14.85 Volts (or there about) requires a Boost type power supply. This would be required Inside the MBA.
    The is the main problem. Apple is not going to put something in a MBA (or any laptop) if it doesn't need to be there.
    My opinion is this will not happen.

    Conceivably someone could come up with a devices the goes between the 5V output charger & the Magsafe input on a MBA. But I doubt it.
    As a rough guesstimate, charge time would be greater than 5 times longer.
    You'd have to bring this extra device around with you. The size of this device & the iPad charger would be similar, so you might as well just use the MagSafe charger.
     
  7. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #7
    No it's not possible.

    If you have the modify the iPhone charger, it wouldn't be able to charge an iPhone anymore and therefore wouldn't be an iPhone charger.
     
  8. iWeekend macrumors regular

    Joined:
    Nov 28, 2012
    #8
    I'm waiting on an official dedicated car charger for laptops myself.
     
  9. 2IS macrumors 68030

    Joined:
    Jan 9, 2011
    #9
    Simple problems call for simple solutions.

    Buy another charger, keep one at home and one in the bag.

    Keep the iPhone charger at home if you want to go minimalist. Just bring the cable and use the MBA's USB port.
     
  10. brand macrumors 601

    brand

    Joined:
    Oct 3, 2006
    Location:
    127.0.0.1
    #10
    The first is an operating system and the second is a piece of hardware. On top of that you say one is outputting and the other is receiving.
     

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