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Lemon battery without copper and zinc metals

  1. Sep 3, 2016 #1
    Hello,

    I have seen a video online that shows how a LED can be lit using a single lemon without using a copper and a zinc nail. They simply stick the LED into the lemon.

    What does that work? I know the lemon contains the electrolyte but don't we always need to dissimilar metals for the battery to work?
    thanks!
     
  2. jcsd
  3. Sep 3, 2016 #2

    nsaspook

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    I think you need a lime for it to work.:rolleyes:
     
  4. Sep 3, 2016 #3
    yeah, true. But why?
     
  5. Sep 3, 2016 #4

    nsaspook

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    It was a joke, the video is a poor fake.
     
  6. Sep 3, 2016 #5

    Bandit127

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    If you wanted to fake it, could you plate one leg with zinc? It would look silver on a video and maybe pass for an "untreated" LED. The anodic index of silver solder is the same as copper according to the table here:
    http://www.engineersedge.com/galvanic_capatability.htm
     
  7. Sep 3, 2016 #6

    nsaspook

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    Let say you had a single cell made with a magnesium/copper plated tiny surface reaction area legs LED that might give 1.6 volts (the penny/nail open voltage is about 0.9) open circuit and drop to half that voltage value with a few micro-amp load because of high internal resistance. Would that work to light an LED?
    1883Fig10.gif
     
    Last edited: Sep 6, 2016
  8. Sep 5, 2016 #7

    NascentOxygen

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    Possibly there could be concealed wires or a battery buried inside the fruit?
     
  9. Sep 7, 2016 #8

    rbelli1

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    It is definitely a shoop. I can tell from the pixels. Third one from the left has shifty eyes.

    BoB
     
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