Building a Voltaic pile

[s***@gmail.com]

Sorry for the wide distribution, but I'm casting a wide net in the
hopes of a speedy solution.

My daughter is trying to build a simple Volta's pile for a school
project. We took twelve shiny new US pennies, twelve circles of
aluminum foil cut slightly smaller than the pennies, and twelve 1-inch
squares of paper towel soaked in salt water. I can't seem to get any
current off of the thing. First we tried touching two wires together
in a darkroom, but couldn't see any sparks. Then I got out my trusty
Radio Shack battery tester, but its needle wouldn't budge. Then I
soaked the paper towels in heavily salted vinegar, but got the same
results. I also tried using several individual pennies and pieces of
foil, but still can't get the battery tester to measure anything.

I'm pretty sure that the battery tester's uncalibrated meter is
measuring voltage, not current, so I'd expect it to show *something*.
All US pennies since 1982 are copper-coated zinc wafers, so I'd expect
there to be enough Cu to react with the vinegar. The foil is plain
heavy-duty Reynolds wrap for baking, so I don't expect that there's any
coating. The salt is Morton's iodized table salt. My stranded wire
will light a flashlight bulb from a AA cell, so it doesn't have any
internal breaks.

This whole thing has me stumped. If anyone can offer any suggestions,
I'd love to hear them; otherwise I'll probably try using an old piece
of copper pipe wrapped in wet paper towels and foil, and if that
doesn't work I'll buy a steel bowl and try a ball of foil floating in
vinegar.

[Paul S.]

Post by s***@gmail.com
Sorry for the wide distribution, but I'm casting a wide net in the
hopes of a speedy solution.
My daughter is trying to build a simple Volta's pile for a school
project. We took twelve shiny new US pennies, twelve circles of
aluminum foil cut slightly smaller than the pennies, and twelve 1-inch
squares of paper towel soaked in salt water. I can't seem to get any
current off of the thing. First we tried touching two wires together
in a darkroom, but couldn't see any sparks. Then I got out my trusty
Radio Shack battery tester, but its needle wouldn't budge. Then I
soaked the paper towels in heavily salted vinegar, but got the same
results. I also tried using several individual pennies and pieces of
foil, but still can't get the battery tester to measure anything.
I'm pretty sure that the battery tester's uncalibrated meter is
measuring voltage, not current, so I'd expect it to show *something*.
All US pennies since 1982 are copper-coated zinc wafers, so I'd expect
there to be enough Cu to react with the vinegar. The foil is plain
heavy-duty Reynolds wrap for baking, so I don't expect that there's any
coating. The salt is Morton's iodized table salt. My stranded wire
will light a flashlight bulb from a AA cell, so it doesn't have any
internal breaks.
This whole thing has me stumped. If anyone can offer any suggestions,
I'd love to hear them; otherwise I'll probably try using an old piece
of copper pipe wrapped in wet paper towels and foil, and if that
doesn't work I'll buy a steel bowl and try a ball of foil floating in
vinegar.

That pile is not going to be capable of generating enough current to make
a visible spark nor drive a battery tester. Try measuring the voltage using
a digital multimeter. They require far less current; I'm sure you read some
kind
of voltage.

[Dave]

the battery tester is probably meant to read current to tell you how good
the battery is.

also, get rid of the salt, you want acid like vinegar or lemon juice or
dissolved vitamin c tablets. and remember, the towels need to be very wet
so the metals have a good path to drive ions through liquid... but they
shouldn't be so wet that the acid bridges between cells or it essentially
just shorts them out. a better material for the dividers is blotting paper,
but the towels will work if you get them wet enough.

just as a quick sanity check, with apple cider vinegar, one penny, and one
square of foil I get .7v at about 2ma. that won't be enough to budge a
battery meter but it registers well on a volt meter. and remember, the
current is limited by the diameter of the penny and foil, stacking more in
series won't increase the current it can generate only the voltage. you
need more surface area to get more current. or hook them in parallel.

Post by s***@gmail.com
Sorry for the wide distribution, but I'm casting a wide net in the
hopes of a speedy solution.
My daughter is trying to build a simple Volta's pile for a school
project. We took twelve shiny new US pennies, twelve circles of
aluminum foil cut slightly smaller than the pennies, and twelve 1-inch
squares of paper towel soaked in salt water. I can't seem to get any
current off of the thing. First we tried touching two wires together
in a darkroom, but couldn't see any sparks. Then I got out my trusty
Radio Shack battery tester, but its needle wouldn't budge. Then I
soaked the paper towels in heavily salted vinegar, but got the same
results. I also tried using several individual pennies and pieces of
foil, but still can't get the battery tester to measure anything.
I'm pretty sure that the battery tester's uncalibrated meter is
measuring voltage, not current, so I'd expect it to show *something*.
All US pennies since 1982 are copper-coated zinc wafers, so I'd expect
there to be enough Cu to react with the vinegar. The foil is plain
heavy-duty Reynolds wrap for baking, so I don't expect that there's any
coating. The salt is Morton's iodized table salt. My stranded wire
will light a flashlight bulb from a AA cell, so it doesn't have any
internal breaks.
This whole thing has me stumped. If anyone can offer any suggestions,
I'd love to hear them; otherwise I'll probably try using an old piece
of copper pipe wrapped in wet paper towels and foil, and if that
doesn't work I'll buy a steel bowl and try a ball of foil floating in
vinegar.

[Billy H]

Post by Dave
the battery tester is probably meant to read current to tell you how good
the battery is.
also, get rid of the salt, you want acid like vinegar or lemon juice or
dissolved vitamin c tablets. and remember, the towels need to be very wet
so the metals have a good path to drive ions through liquid... but they
shouldn't be so wet that the acid bridges between cells or it essentially
just shorts them out. a better material for the dividers is blotting
paper, but the towels will work if you get them wet enough.
just as a quick sanity check, with apple cider vinegar, one penny, and one
square of foil I get .7v at about 2ma. that won't be enough to budge a
battery meter but it registers well on a volt meter. and remember, the
current is limited by the diameter of the penny and foil, stacking more in
series won't increase the current it can generate only the voltage. you
need more surface area to get more current. or hook them in parallel.

sanity check? is that + or - 0.7 volts? 2ma, that's pretty good.

powerful mind there sir!! :o)

Post by Dave

Post by s***@gmail.com
Sorry for the wide distribution, but I'm casting a wide net in the
hopes of a speedy solution.
My daughter is trying to build a simple Volta's pile for a school
project. We took twelve shiny new US pennies, twelve circles of
aluminum foil cut slightly smaller than the pennies, and twelve 1-inch
squares of paper towel soaked in salt water. I can't seem to get any
current off of the thing. First we tried touching two wires together
in a darkroom, but couldn't see any sparks. Then I got out my trusty
Radio Shack battery tester, but its needle wouldn't budge. Then I
soaked the paper towels in heavily salted vinegar, but got the same
results. I also tried using several individual pennies and pieces of
foil, but still can't get the battery tester to measure anything.
I'm pretty sure that the battery tester's uncalibrated meter is
measuring voltage, not current, so I'd expect it to show *something*.
All US pennies since 1982 are copper-coated zinc wafers, so I'd expect
there to be enough Cu to react with the vinegar. The foil is plain
heavy-duty Reynolds wrap for baking, so I don't expect that there's any
coating. The salt is Morton's iodized table salt. My stranded wire
will light a flashlight bulb from a AA cell, so it doesn't have any
internal breaks.
This whole thing has me stumped. If anyone can offer any suggestions,
I'd love to hear them; otherwise I'll probably try using an old piece
of copper pipe wrapped in wet paper towels and foil, and if that
doesn't work I'll buy a steel bowl and try a ball of foil floating in
vinegar.

[s***@gmail.com]

Many thanks to everyone who replied!

Post by Dave
the battery tester is probably meant to read current to tell you how good
the battery is.

Here's the incredibly cheap tester I used: http://tinyurl.com/8djef
-or-
http://www.radioshack.com/product/index.jsp?productId=2103165&cp=2032058.2032235.2032306&parentPage=family

Post by Dave
also, get rid of the salt, you want acid like vinegar or lemon juice or
dissolved vitamin c tablets. and remember, the towels need to be very wet
so the metals have a good path to drive ions through liquid... but they
shouldn't be so wet that the acid bridges between cells or it essentially
just shorts them out. a better material for the dividers is blotting paper,
but the towels will work if you get them wet enough.

That may be my problem, then. I worried about the foil shorting things
out, but not the paper. Those 1" squares flopped everywhere.

Post by Dave
just as a quick sanity check, with apple cider vinegar, one penny, and one
square of foil I get .7v at about 2ma. that won't be enough to budge a
battery meter but it registers well on a volt meter.

As an ex-EE, I'm ashamed to say that I haven't seen my voltmeter in
ages. I guess I need to go buy a new one.

Post by Dave
and remember, the
current is limited by the diameter of the penny and foil, stacking more in
series won't increase the current it can generate only the voltage. you
need more surface area to get more current. or hook them in parallel.

We're working off of a project in a book which claimed that twelve
cells in series would create a visible spark. Oh, well.

[Roy Lewallen]

Post by s***@gmail.com
. . .
We're working off of a project in a book which claimed that twelve
cells in series would create a visible spark. Oh, well.

Connect it to a big electrolytic capacitor if that's permissible and let
it charge for a little while. You should be able to get a decent spark
when it's shorted.

Roy Lewallen

[John R. Copeland]

Post by s***@gmail.com
As an ex-EE, I'm ashamed to say that I haven't seen my voltmeter in
ages. I guess I need to go buy a new one.
We're working off of a project in a book which claimed that twelve
cells in series would create a visible spark. Oh, well.

As an ex-EE, you might also appreciate that a little added inductance
in the circuit could enhance the sparking effect nicely, if that's your aim.

[Rotes Sapiens]

On Sun, 11 Dec 2005 16:36:12 GMT, "John R. Copeland"

Post by John R. Copeland

Post by s***@gmail.com
As an ex-EE, I'm ashamed to say that I haven't seen my voltmeter in
ages. I guess I need to go buy a new one.

DMMs can be purchased very cheaply nowadays, some of them even have
transistor and diode testing.

Post by John R. Copeland

Post by s***@gmail.com
We're working off of a project in a book which claimed that twelve
cells in series would create a visible spark. Oh, well.

Did you use alkalines or NiCd cells? Carbon-Zinc or Ni-Mh don't work
so well.

Post by John R. Copeland
As an ex-EE, you might also appreciate that a little added inductance
in the circuit could enhance the sparking effect nicely, if that's your aim.

Or even a large capacitor, to compensate for the internal impedance of
the batteries.



Sig:
"Whether you believe you can do a thing or not, you are right." -Henry Ford

[Autymn D. C.]

Post by Rotes Sapiens
"Whether you believe you can do a thing or not, you are right." -Henry Ford

nuh uh, there are accidents

[Dave]

p.s. make sure the foil isn't some of that new anti-stick coated stuff, that
may act as an insulator.

Post by s***@gmail.com
Sorry for the wide distribution, but I'm casting a wide net in the
hopes of a speedy solution.
My daughter is trying to build a simple Volta's pile for a school
project. We took twelve shiny new US pennies, twelve circles of
aluminum foil cut slightly smaller than the pennies, and twelve 1-inch
squares of paper towel soaked in salt water. I can't seem to get any
current off of the thing. First we tried touching two wires together
in a darkroom, but couldn't see any sparks. Then I got out my trusty
Radio Shack battery tester, but its needle wouldn't budge. Then I
soaked the paper towels in heavily salted vinegar, but got the same
results. I also tried using several individual pennies and pieces of
foil, but still can't get the battery tester to measure anything.
I'm pretty sure that the battery tester's uncalibrated meter is
measuring voltage, not current, so I'd expect it to show *something*.
All US pennies since 1982 are copper-coated zinc wafers, so I'd expect
there to be enough Cu to react with the vinegar. The foil is plain
heavy-duty Reynolds wrap for baking, so I don't expect that there's any
coating. The salt is Morton's iodized table salt. My stranded wire
will light a flashlight bulb from a AA cell, so it doesn't have any
internal breaks.
This whole thing has me stumped. If anyone can offer any suggestions,
I'd love to hear them; otherwise I'll probably try using an old piece
of copper pipe wrapped in wet paper towels and foil, and if that
doesn't work I'll buy a steel bowl and try a ball of foil floating in
vinegar.

[John Beardmore]

Post by Dave
p.s. make sure the foil isn't some of that new anti-stick coated stuff, that
may act as an insulator.

Come to think of it, the oxide layer on aluminium almost certainly won't
make it good choice for this sort of experiment. Good electrode
potential, poor reaction kinetics.


Cheers, J/.

[s***@sbcglobal.net]

On 12/10/05 6:35 AM, in article

Post by s***@gmail.com
Sorry for the wide distribution, but I'm casting a wide net in the
hopes of a speedy solution.
My daughter is trying to build a simple Volta's pile for a school
project. We took twelve shiny new US pennies, twelve circles of
aluminum foil cut slightly smaller than the pennies, and twelve 1-inch
squares of paper towel soaked in salt water. I can't seem to get any
current off of the thing. First we tried touching two wires together
in a darkroom, but couldn't see any sparks. Then I got out my trusty
Radio Shack battery tester, but its needle wouldn't budge. Then I
soaked the paper towels in heavily salted vinegar, but got the same
results. I also tried using several individual pennies and pieces of
foil, but still can't get the battery tester to measure anything.
I'm pretty sure that the battery tester's uncalibrated meter is
measuring voltage, not current, so I'd expect it to show *something*.
All US pennies since 1982 are copper-coated zinc wafers, so I'd expect
there to be enough Cu to react with the vinegar. The foil is plain
heavy-duty Reynolds wrap for baking, so I don't expect that there's any
coating. The salt is Morton's iodized table salt. My stranded wire
will light a flashlight bulb from a AA cell, so it doesn't have any
internal breaks.
This whole thing has me stumped. If anyone can offer any suggestions,
I'd love to hear them; otherwise I'll probably try using an old piece
of copper pipe wrapped in wet paper towels and foil, and if that
doesn't work I'll buy a steel bowl and try a ball of foil floating in
vinegar.

My guess is that the oxide coating on the Al foil is preventing conduction.
Even if you scrape the foil, the oxide will reform. Use your meter in the
ohmmeter mode to see if the foil contacts the penny electrically.

Even so, this is not a good way to go. You would be better off removing the
Cu from the pennies so as to get Zn disks. You should be able to find Zn
sheet or at least galvanized steel. These will form the anodes of the cell.
Get sheet Cu for the cathodes. If nowhere else, sheet Cu is available at
many garden centers for repelling snails.

It would be best to use a diluted real acid. Start with 5:1 (water:acid) for
the HCl or 10:1 for the H2SO4. Hydrochloric acid is available at pool supply
stores as muriatic acid. Sulfuric acid is also good and available as drain
cleaner. Be careful with either one, especially the concentrated H2SO4.
Always add the acid to the standing water. Ammonium sulfate might also do
the job, because it will be acidic in water solution.

Bill

-- Ferme le Bush

[c***@hotmail.com]

try some pennies and get some galvanized sheet metal...any heating and
cooling outfit can cut you some little squares of sheetmetal. might
even have some copper sheet laying around...or you could get some
copper pipe and cut it down the middle...spread and beat out flat with
hammer and cut some squares.....or you could get some galvanized
washers at the hardware store....
hardware store alsom might have small piece of galvanized metal
strapping they could let you have.

try lemon juice as an acid.....and maybe do some research on sal
ammoniac....I think thats what people used years ago to make homemade
cells......

[Don Kelly]

----------------------------

Post by c***@hotmail.com
try some pennies and get some galvanized sheet metal...any heating and
cooling outfit can cut you some little squares of sheetmetal. might
even have some copper sheet laying around...or you could get some
copper pipe and cut it down the middle...spread and beat out flat with
hammer and cut some squares.....or you could get some galvanized
washers at the hardware store....
hardware store alsom might have small piece of galvanized metal
strapping they could let you have.
try lemon juice as an acid.....and maybe do some research on sal
ammoniac....I think thats what people used years ago to make homemade
cells......

Put the lemon juice on blotting paper between the pennies and galvanised
washers. This keeps the electrolyte where it belongs.
Alternatively stick a copper wire and a galvanised nail into a lemon.

[s***@gmail.com]

Post by c***@hotmail.com
try some pennies and get some galvanized sheet metal...any heating and
cooling outfit can cut you some little squares of sheetmetal. might
even have some copper sheet laying around...or you could get some
copper pipe and cut it down the middle...spread and beat out flat with
hammer and cut some squares.....or you could get some galvanized
washers at the hardware store....
hardware store alsom might have small piece of galvanized metal
strapping they could let you have.

I wasn't going to go quite that far yet, although I was thinking about
a length of copper pipe wrapped in vinegar-soaked paper towels, with
aluminum foil wrapped around that. Theoretically, that should produce
1.6 volts, and the surface area of the pipe should generate a fair
current.

Post by c***@hotmail.com
try lemon juice as an acid.....and maybe do some research on sal
ammoniac....I think thats what people used years ago to make homemade
cells......

I recall seeing a cell made from a penny and a dime stuck into a lemon.
I'll look into the sal ammoniac as well. Thanks!

[Evgenij Barsukov]

Extremely low current is caused by passivation of Al. It is as active
as a piece of glass.
To make a magic change, drop a some CuSO4 into the electrolyte.
It will strip Al of passivation layer. Don't put too much or Al
will dissolve too fast.
Also make sure you use reasonably thick paper-towels between
your electrodes, so the metallic Cu that is being produced is not
going to short it out.

Regards,
Yevgen

Post by s***@gmail.com
Sorry for the wide distribution, but I'm casting a wide net in the
hopes of a speedy solution.
My daughter is trying to build a simple Volta's pile for a school
project. We took twelve shiny new US pennies, twelve circles of
aluminum foil cut slightly smaller than the pennies, and twelve 1-inch
squares of paper towel soaked in salt water. I can't seem to get any
current off of the thing. First we tried touching two wires together
in a darkroom, but couldn't see any sparks. Then I got out my trusty
Radio Shack battery tester, but its needle wouldn't budge. Then I
soaked the paper towels in heavily salted vinegar, but got the same
results. I also tried using several individual pennies and pieces of
foil, but still can't get the battery tester to measure anything.
I'm pretty sure that the battery tester's uncalibrated meter is
measuring voltage, not current, so I'd expect it to show *something*.
All US pennies since 1982 are copper-coated zinc wafers, so I'd expect
there to be enough Cu to react with the vinegar. The foil is plain
heavy-duty Reynolds wrap for baking, so I don't expect that there's any
coating. The salt is Morton's iodized table salt. My stranded wire
will light a flashlight bulb from a AA cell, so it doesn't have any
internal breaks.
This whole thing has me stumped. If anyone can offer any suggestions,
I'd love to hear them; otherwise I'll probably try using an old piece
of copper pipe wrapped in wet paper towels and foil, and if that
doesn't work I'll buy a steel bowl and try a ball of foil floating in
vinegar.