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Water battery

  1. Sep 14, 2010 #1
    Hi, everyone.
    I stumbled upon http://video.google.com/videoplay?docid=6491441475172785592#" [Broken]

    I can't quite figure out how it works, so I figured I'd throw it out to you all.

    I got so far as to come to the conclusion that it has to do with a buildup of static electricity and that, since the setup is symmetrical, the direction of the current is determined early on by random imbalances, and doesn't have to be the same direction each time. Also, I've ruled out the triboelectric effect, because the water is only hitting the bottom of the drum in the beginning, but soon, it's just hitting other water.

    I say all that just to let you know I took a stab at it before crawling shamelessly to the hive mind.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Sep 16, 2010 #2


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    Interesting. I have no guess thats better than yours though.
  4. Sep 17, 2010 #3
    This is actually a pretty cool device.

    You are correct about the random imbalances. They are caused by dry air which can easily electrify one of the 2 bottomless cans. So basically what happens is that one of those cans gets charged by the air, and it can be either of those cans. The charged can either attracts or repells electrons on the tip of the valve, and when water starts dripping from it, it carries some of the charge with it down to the "trash can". This is connected with the other bottomless paintcan, which gets an opposite charge compared to the first bottomless paintcan. Now this paintcan does the same, only with an opposite charge. The trashcans keep charging up until the voltage between the 2 metal balls is big enough to electrically discharge through air.

    The reason why the stream of water spreads is that the water and the bottomless paintcan are oppositely charged. As the charge in the trashcan connected to that paintcan builds up, the bigger the attraction between the dripping water and the paintcan.

    I tried to explain shortly, but if you are interested in more details, go to http://amasci.com/emotor/kelvin.html
  5. Sep 17, 2010 #4
    I'm not really adding to this discussion but I just wanted to say this is mind-bogglingly awesome, and thanks for sharing!
  6. Sep 17, 2010 #5
    Beautiful, Fawk3s!!

    Of course! The drops separate! That was the big clue I was missing.
    Now that I understand it, the contraption is that much more amazing. Isn't it funny how that works?
  7. Sep 26, 2010 #6
    Very interesting! I will try to do it myself.
    Using two separate water sources would kill the experiment right?
  8. Sep 26, 2010 #7
    Hm Im not sure what you mean. The two drippers taking water from separate sources wouldnt make much difference if I got it right. Just make sure the sources are grounded.
  9. Sep 26, 2010 #8
    How would I ground it? Connect each water source together? Wouldn't this just cause a charge balance and destroy the experiment?
  10. Sep 26, 2010 #9


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    Charge inbalance is in the target tanks, not in the sources.

    Connect sources together and with the earth.
  11. Sep 26, 2010 #10
    Yes, the charge imbalances in the water sources have nothing to do with the experiment. In order for the water sources to stay neutral you need to either connect them together and one to the ground or both separatedly to the ground.
  12. Sep 26, 2010 #11
    Of course, as everyone here knows, this is NOT free energy.

    Not that it was implied in anyway, but for the casual onlooker thought I might state that.
    More energy is required to set-up and maintain the system than the energy derived.

    \Anywhoes... cool experiment!
  13. Sep 26, 2010 #12
    Can someone explain how the water drops "pull off" charges from the nozzles? I understand that the conducting nozzles have charge polarization, but how does that make the water charged when it drips off?
  14. Sep 26, 2010 #13
    Doesn't the charge inbalance arise from the firsts drops of water, one of which is more charged than the other and thus start a positive feedback cycle?
  15. Sep 27, 2010 #14


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    Yes, but these are just random fluctuations. Almost all droplets are charged, but they are neutral on avergae. This system uses initial random difference to create a positive fedback, which makes droplets charged on average.
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