Should my Charing lead be switched on at the wall all the time?

Discussion in 'Apple Watch' started by MartinAppleGuy, Nov 22, 2016.

  1. MartinAppleGuy macrumors 68020

    MartinAppleGuy

    Joined:
    Sep 27, 2013
    #1
    Is it ok to leave the charging puck on at the wall at all times? Does it draw any electricity when the Apple Watch isn't on it?
     
  2. Julien macrumors G4

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #2
    What do you do with your iPhone charger? Do the same.
     
  3. MartinAppleGuy thread starter macrumors 68020

    MartinAppleGuy

    Joined:
    Sep 27, 2013
    #3
    Well it gets switched off when not in use, but my Apple Watch is using a socket that is hard to access. I'm just wondering what other people do and if it will draw energy. Boy at the Apple Store said it was fine but just checking.
     
  4. Furzul macrumors 6502

    Furzul

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    Jan 13, 2013
    Location:
    Derbyshire, England
    #4
    I use a charging stand and leave it on all the time and charge it every night, never had a problem.
     
  5. Manrico1, Nov 22, 2016
    Last edited: Nov 22, 2016

    Manrico1 macrumors member

    Manrico1

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    Oct 7, 2016
    Location:
    Crema, Lombardia
    #5
    Sure not a problem but it should draw a very little of energy even while not charging
     
  6. Beards macrumors 6502a

    Beards

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    Mar 22, 2014
    Location:
    Derbyshire UK
    #6
    Mine is the same' the socket is located behind a set of heavy bedside drawers. It's been left on permanently for the past 18 months. No issues here.
     
  7. Newtons Apple macrumors Core

    Newtons Apple

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    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #7
    The charging puck has no idea if it is charging a watch or not. It uses the same amount of voltage no matter what so if you are one of those green types, you should unplug it when not in use. Do not forget to unplug those clocks when not looking at them, too.
     
  8. MartinAppleGuy thread starter macrumors 68020

    MartinAppleGuy

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    Sep 27, 2013
    #8
    Can I actually ask a question with such a sarcastic response?
     
  9. Newtons Apple macrumors Core

    Newtons Apple

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    Mar 12, 2014
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    Jacksonville, Florida
    #9
    Why of course you can ask. It IS McRumors!
     
  10. MartinAppleGuy thread starter macrumors 68020

    MartinAppleGuy

    Joined:
    Sep 27, 2013
    #10
    So can the puck/wall charger know of it is to draw energy or not?
     
  11. Manrico1 macrumors member

    Manrico1

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    Oct 7, 2016
    Location:
    Crema, Lombardia
    #11
    As far as I know: if you are charging, you draw the energy used for charging (of course). If you're not chanrging, the transformer inside the charger should draw a little energy, much less than while charging but always present (sorry, I'm not mother language with English)
     
  12. Newtons Apple macrumors Core

    Newtons Apple

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    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #12
    No, the puck is creating the same magnetic field no matter if attached to a watch or not. It gets no feedback from the watch.
    --- Post Merged, Nov 23, 2016 ---
    There is no direct electrical contact between the watch and the charger. The charger uses the same amount of power no matter if it is charging or not. It is not like plugging your phone in, there is no connection to the puck.
     
  13. Manrico1 macrumors member

    Manrico1

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    Oct 7, 2016
    Location:
    Crema, Lombardia
    #13
    Are you sure? a transformer has different power draw if he's in use or in idle
     
  14. Newtons Apple, Nov 23, 2016
    Last edited: Nov 23, 2016

    Newtons Apple macrumors Core

    Newtons Apple

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    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #14
    Normally that would be correct but not in this case.

    The transformer creates the same magnetic field no matter if the watch is there or not. It is different than plugging in something like your iPhone which has a direct electrical connection.

    How would the transformer know it has a watch by the puck?
     
  15. jakerichva Suspended

    Joined:
    Jul 12, 2008
    #15
    The puck will know because the impedance in the circuit with the watch will change. Yes, it's NOT connected directly to the watch, but the appearance of the watch in the magnetic field and the draw of the watch on the field from the puck will, in fact, show up in the power demand of the puck. Just like the input coils of a transformer do not directly connect to the output coils, when power is taken from the output coils, the input coils see the load change. So the puck, while simply plugged in, will draw a bit of power, but when the watch is attached and charging, the total power use will increase.

    All that said, we're talking tiny amounts of power, so I wouldn't worry about it.
     
  16. clauzzz203 macrumors 6502

    Joined:
    Sep 18, 2012
    #16
    You can use physics to figure it out. If your charging puck gets warm without a Watch on it, it consumes power.

    Energy is conservated in the universe, if it's warm it draws power aka electrical energy gets converted to thermal energy and electromagnetic fields (for the inductive charge). Since it's cold when not with a Watch on it, the logical conclusion is that it only draws power when activated by a Watch.

    So go and enjoy more important things in life :) and don't wear out your plugs needlessly
     
  17. bniu macrumors 6502a

    Joined:
    Mar 21, 2010
    #17
    In my experience, maybe it makes a difference of a few pennies a year, not enough for me to even care.

    I also leave lightning cables plugged in all the time, I remember reading somewhere that the average total electrical usage of a whole year of using an iPad was $2.
     
  18. winterny macrumors 6502

    Joined:
    Jul 5, 2010
    #18
    Interestingly, I checked my charging puck with a Flir thermal imaging camera after the puck had been plugged in overnight without charging a watch. It was clearly warmer than the environment around it.

    So, yes, it does in fact continue drawing power constantly.
     
  19. clauzzz203 macrumors 6502

    Joined:
    Sep 18, 2012
    #19
    I must admit, you've left me without comment lol. It's still colder by a factor, than with a watch on it. And also it must have a small field that will be disturbed by the watch to trigger full field charging, so it will stay on at some percent.

    But still you're looking at (guessing here) 1w per month standby vs 3w per month charging... A single lightbulb is 60w, a kitchen appliance 5w just sitting turned off.

    Bottom line, more power is being consumed to manufacture a replacement power socket :p
     
  20. Ivanovitchk macrumors regular

    Ivanovitchk

    Joined:
    Sep 9, 2010
    Location:
    Paris, FR
    #20
    The charging pluck is not dumb.

    There is bidirectional communication between the pluck and the watch to negociate, allow, and modulate power ouput.

    Qi-wireless standard devices also use the same mechanisms. You just can't put a matching coil and expect the receiver to draw power. It won't happen without authentification.

    Regarding the energy savings of unplugging the AC/DC block every day I wouldn't do it. There is an higher probability that the constant mechanical stress will damage either the socket or the transformer which will end up costing much more than the dollar a year you'll save in utility bill.

    Also, it's very probable you have much much larger energy wasting habits / devices to eliminate before you start chasing the milliwatts ghosts.
     
  21. Newtons Apple macrumors Core

    Newtons Apple

    Joined:
    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #21
    I am pretty sure it is the battery that is getting warm.
    --- Post Merged, Nov 25, 2016 ---
    If that is so my Oral B wireless toothbrush charger is communicating with my Apple Watch as I can make my Watch chime and go into Charge mode by holding it just right. :p
     
  22. clauzzz203 macrumors 6502

    Joined:
    Sep 18, 2012
    #22
    You know that, you are making us use a lot of electricity, when we reply
     
  23. Ivanovitchk macrumors regular

    Ivanovitchk

    Joined:
    Sep 9, 2010
    Location:
    Paris, FR
    #23
    Might light up the watch as it's detecting an em field but I assure you it won't charge as there won't be proper auth.

    It's the same the other way round. The AW pluck will wake up the toothbrush but rapidly shut off as the authentification is missing.
     
  24. Newtons Apple macrumors Core

    Newtons Apple

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    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #24
    Sorry man but still thinking the puck is stupid.
     
  25. Ivanovitchk, Nov 27, 2016
    Last edited: Nov 27, 2016

    Ivanovitchk macrumors regular

    Ivanovitchk

    Joined:
    Sep 9, 2010
    Location:
    Paris, FR
    #25
    I worked on Qi-wireless power transfer designs. Trust me, I'm an engineer :D.

    The AW puck has been confirmed to be Qi-compliant and will charge any Qi-certified device *
    http://appleinsider.com/articles/15...-compliant-with-qi-wireless-charging-standard

    The AW itself is Qi-compliant in principle but an additional layer of proprietary auth restricts it to the official puck.

    Similar auth mechanisms are found in Lightning cables. If a 3rd party cable lacks the MFi chip (or use a spoofed one). It will not charge an iDevice (or will for a very short time and then issue an error message)

    Qi-standard devices, including the AW, use the following system architecture. Notice the "Communications & Control Unit":

    [​IMG]


    * electric toothbrushes (Braun Oral-b / Philips Sonicare) don't use Qi, but a fully proprietary design that's one of the oldest large-scale consumer wireless power transfer system in use (15+ years). They don't have any auth / comms module and their implementation can be 100% analogue.
     

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