Working Air Battery

[mscoffman]

@all

Guys have a look a this fire from a potato.

One potato emptied in the middle filed with salt and toothpaste , 2 wire they seem the same material , so i don't thing galvanic here , 5 minute and voila enough current to start a fire , its probably a trick but if real really worth looking into .

http://wickedhowtos.com/index.php/2009/05/28/how-to-make-fire-with-a-potato-potato-battery-cotton-ball-fire/

@Mk1

It’s a guess, but most likely the potato battery is voltaic but not
a normal battery reaction, One where the reaction does not go ahead
unless current flows though a low ohm load external resistance.
It probably is a standard ionic Chemical reaction that is occurring
as a chemical reactant concentrations flows towards the center,
and that the wires act as voltage probes rather then chemical
reaction sites.

Most likely the toothpaste needs to contain sodium fluoride.
Fluorine is the most powerful and electronegative of all ions.
Most likely the salt acts as an astringent to draw fluids out
of the potato tissue. Raw potatoes contain Alkaloids Which
are chemically basic end make raw potatoes taste somewhat
bitter. It also might be the calcium metal in the potato.

It would be interesting to try other nightshade foods: tomatoes
and eggplant, too see if these might make good temporary
batteries too.

The fire part occurs from the small electrical spark. Shesh,
lunch could get dangerous.

:S:MarkSCoffman

[Mk1]

@all

I just posted my first battery prototype here

http://www.overunity.com/index.php?topic=9346.msg248575#new

With pictures and meter reading ...

Mark

[jeanna]

@ Dr Zoldberg,
It would be great if you can give us more information about the gel electrodes. That is very interesting information, indeed.

@Conrad.
This is probably the answer to my puzzlement.

I will see if I can set up my scope in a way to measure what you are seeing in yours. Meantime, I will figure on the half point and see if it corresponds to the amount of light output I am seeing.

Thank you,

jeanna

[sm0ky2]

if you take a potato, and you place 2 probes in it, at a distance
it creates a nice battery. its a potassium reaction that is stimulated by the current flow. an almost identicle thing happens with a lemon. [2K + 2H2O -> 2KOH + H2] the hydrogen fuses with oxygen at the anode (?) and forms back into water.

you can run a clock straight off a potato for weeks. just put probes on the plug and stick it in. adding the salt probably acts as some sort of catalyst. (or reactant with the toothpase to help start the fire?) potatoes are actually a suprising source of energy.
if you were willing to sacrifice the minerals in your soil, you could probably run the farm off of them, instead of selling them for food...

[DrZoidberg]

@ Dr Zoldberg,
It would be great if you can give us more information about the gel electrodes. That is very interesting information, indeed.

I used a small medical solid gel electrode and put a copper coin and a piece of zinc on it. I got about 0.85V and 40 µA. If I use a wet paper towel instead I get 100 µA. So I get less then half the current from the solid gel but the big advantage is that it never dries out.
The current may seem a little low but that's because I wasn't able to put the gel in between the coin and the zinc. I put both on the same side of the gel electrode.
It also is sticky which should come in handy if I want to use manganese dioxide in my battery.
Now I just need to find out if I can dissolve that gel, maybe in acetone, so I can soak paper in it. Then maybe I can build a powerful zamboni pile.