Halloween Props: Pumpkin Battery

This one would make a nice centerpiece for your Halloween party. It’s a battery with tiny pumpkins serving as the cells. [EM Daniels] shows us how to clear out the pumpkins, fill them with some freshly mixed electrolyte, and he even throws in the directions for baking the pumpkin seeds.

Each pumpkin will need a pair of conductors made of dissimilar metals to serve as the anode and cathode. Copper wire is used for one, aluminum for the other, and both wires have a spiral pattern bent on one end to increase the surface area that contacts the electrolytic solution. Now just boil up a slurry of vinegar, gelatin, and salt, then let it sit in the fridge over night. [EM Daniels] was able get 1.5V out of this project (enough to light one LED) for two hours, and 1.4V for six hours by using seven of the pumpkin cells in series.

[Thanks Karen]

10 thoughts on “Halloween Props: Pumpkin Battery

  1. Very cool project, in the Mad Scientist fashion!

    I was mislead by the intro, though. As I read straight through it, I got the impression that he first tried one pumpkin cell, with which he was able to power one LED at 1.5V for two hours, and then was able to power one LED at 1.4V for six hours after putting 7 of them in series. After reading the Instructable(boo!), I see that he tried 6 cells in series from the beginning to power a seventh pumpkin with an LED in it, getting 1.5V for the first two hours, and then measuring 1.4V after six hours of use. I seems like this would be clearer if “1.4V for six hours by using seven” were changed to read “1.4V after six hours, by using six”.

    Thanks for the post HAD!

  2. i was hoping he used an electrolyte but kinda dismayed at the longevity of the results i wonder if you could get just as much or more power by using candle in the ‘power’ pumpkins and suspending a thermocouple made of said dissimilar metals in the flame.

  3. For anyone interested, google “Nathan Stubblefield” for his work in taking electrical potential directly from the ground (actually, his farm land) and using it for light and communication, all before the turn of the century. (in the 1800’s!)

    I know, it lacks the charm of pumpkin power, but it’s only slightly less convenient as a flashlight power source!…lol

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