a Voltaic Pile Battery

[sm0ky2]

In honor of Count Alessandro Volta

i have decided to recreate a version of the original (modern society) electrochemical battery.

Materials::

a piece of board
soda cans
pennies
5 wooden dowels
10 small nails
scrap paper
water
salt
2 pieces of wire
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The photos below show the materials used, and a small demonstration stack that measures in at just under 4 Volts.

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Method:

First cut the paper into small pices/strips/shredded ect.
  and soak it in water for a few hours until it becomes a mush
then add salt ( ideal quantity is unknown, so i just add some salt)

Next, cut the top and bottom off of the soda cans, and sand off the outer protective coatings paint (outside) and wax (inside), to expose the aluminum surface.
Then cut the can into strips about the width of a penny, then cut the strips into squares the size of a penny.

What you want to do is layer the cells Aluminum (negative), a thin layer of salty-paper substrate, then a penny.
place the next piece of aluminum directly on top of the penny and continue until you achieve the desired voltage.

Each cell is approx 0.5v , they do add up in series, but mine are not adding up axactly as i expected, adding two cells results in a value slightly less than 1 volt,  so my 4volt stack is made up of 15-cells.
This might be a construction issue, i'll continue to run tests as i build this thing.

The "frame" i came up with is similar to volta's original "pile", with a rod in the center and 4 rods around it, (wooden dowels) and in the spaces between them will be 4 stacks of cells, connected in parallel.


[why the substrate?]
i have seen cells made of single pieces of paper, or even coffee filters soaked in salt water. These work just fine.
i am using the substrate, because it results in a bit thicker paper layer, tests have shown that this increases the output currrent of the cells.

my small "test" stack, is about as big as its going to get for now, because it wants to fall over,. so i will construct the frame and post more later. For those interested in actual current readings, i'll have to do that once the completed battery is assembled. my digital meter suffered an electrostatic mishap (again), and this analog meter has limited current settings. all i can say at this point is the 4v stack is somewhere between:
100 microamps (pegged the needle) and 1 ma. (doesnt register)

Enjoy

[sm0ky2]

ok so,... the "circular" design i was going for didnt hold things together as well as i had hoped,
so i went with just 4 stacks in a straight line..

I got this thing up to 9 volts now, with 32 cells in a stack
There seems to be a voltage issue with surface contact on the pennies, so i may have to go through and remove any tarnish or dirt from them before assembling the battery, but so far it seems to be working well.

[onthecuttingedge2005]

I did the same experiment 20 years ago but I used zinc penny's sanded down to reveal the zinc and use pre 1970's copper pennys and used flouride tooth paste as the electrolyte, worked pretty good, fun experiment indeed.

Jerry

[b_rads]

This is one I made 4 months ago.  A couple ml water every 6 weeks or so and still working.    A voltaic pile battery using magnesium, copper foil, felt, and plain tap water with Alum.  Open circuit shows slightly over 4volts.  Enough under load to power a 5mm red LED directly.  Apply pressure to the stack and the voltage and amps will improve.
Brad S

[sm0ky2]

I did the same experiment 20 years ago but I used zinc penny's sanded down to reveal the zinc and use pre 1970's copper pennys and used flouride tooth paste as the electrolyte, worked pretty good, fun experiment indeed.

Jerry

is that what that is? Zinc?  i tried to sand a few of them, but it seems the pennies made after 1989 or so are not copper, but actually copper-coated, with a silverish alloy inside, that is much closer to aluminum on the electrochemical scale, only producing 0.15v between penny and aluminum, so i left the copper coating on to get the full 0.5v per cell.
Zinc would make sense... i didnt bother to study up on it, just figured it was best to not sand them, but clean them instead.

My goal is to achieve at least 12 volts from this. To test its pheasibility as a "doomsday power supply", made from very-common materials.