Usb Charger Power Consumption?

Discussion in 'Tech/Mech General' started by berni109, Jun 1, 2015.

  1. berni109

    berni109 Funster

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    Wired one of these cig lighter replacements to permanent live and it drawing 0.018 amp. for the led
    So in 24 hours it will use 0.432 amp or 3.042 amp every week.
    Does that sound right?
     
  2. DBK

    DBK Funster

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    I guess the .018 amps is the current drawn by the led plus the current drawn on standby by the electronics inside the thing which reduce the 12v input to 5v. I suspect the light only uses a fraction of the current, the bulk will be the electronics.

    And your second figures, assuming the current reading is correct* are amp-hours and the maths look fine.

    *It is such a low current your meter may not be accurate - I doubt my cheapie screwfix one would be.
     
  3. Wildman

    Wildman Read Only Funster

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    all down to the internal resistance of the multimeter.
     
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  4. berni109

    berni109 Funster

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    @Wildman is it going be in the general ball park though?
    It not a cheepy meter but obviously not top of the range.
     
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  5. Steve

    Steve Funster Life Member

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    looks about right, all these little bits start to add up.
    Steve
     
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  6. Borderland

    Borderland Funster

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    From memory, 18mA (0.018 amp) sounds about right for a LED
     
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  7. berni109

    berni109 Funster

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    Thanks for the responses
     
  8. pappajohn

    pappajohn Funster Life Member

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    Wire it to an ignition switched supply instead.
    Mine is wired to the cig lighter socket which turns off 1/2 hr after ign off or as soon as a door is opened whichever is sooner.
     
  9. Gromett

    Gromett Funster

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    I have snipped the Leds in mine. they were disturbing me at night.
     
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  10. Cavs

    Cavs Funster

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    I fitted one of these and it burnt out, I assumed because it was on all the time connected to the leisure battery. The supplier replaced it foc, and I wired the replacement with an in line switch so it's on only when being used.
     
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  11. Reallyretired

    Reallyretired Funster

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    The high tech solution. I stuck a blob of blu-tac on mine, more easily reversible.
     
  12. Gromett

    Gromett Funster

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    I tried that but as it ages (they do get warm) it eventually falls off.

    I am happy to strip things down and snip away though.... I just did the same with my USB hub which has one of these ultra bright blue LED's in. Seriously irritating at night.
     
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