Penny and Nickel Battery

This instructable is a battery made of pennies, salt water, and nickels. It produces voltage much like a battery, but you use pennies and nickels instead. It is a fun project for those pennies and nickels you don't wish to use anymore. Most of us don't usually go to the coinstars, and our change just piles up, so make a battery out of them!


Go to the next step for Items you need.

Step 1 What do I need?

Here are the items you will need:

For about 1 volt, you will need:

(6)Pennies
(6)Nickels
(6)Pieces of paper towel cut to a size smaller than the nickel
(1)Glass of water with 2 Tablespoons of salt dissolved in it

Optional: Multimeter to measure the amount of voltage you have prodced.

Comments

[westfw]

Ever since pennies became zinc with a thin outer layer of copper, I've been intrigued by the idea of building a battery from ONLY pennies. But I can't think of an easy way to get rid of the copper on one side (and part of the edge? Of the penny. Any ideas out there?

[jack_of_all_everything]

ferric chloride solution or sodium metabisulfate in peroxide. same stuff used to etch a PCB should take the copper off.

[Davidl3]

Sand it.
http://www.instructables.com/id/The-Penny-Battery/

[triggernum5]

They have these nifty tools now called files..:) Or you could try contact electrolyzing it..

[threecheersfornick]

We messed around with pennies in metalworks, and figured out that sanding them or filing them will get them nice and silvery shiney pretty quickly. (If you use a dremel with sandpaper it'll take under a minute.)

[ironsmiter]

Coat one side with a chemical resist(Asphaltum, tar, hotglue, etc). Place in a warm citric acid bath Check every hour or so. The stronger the solution, and the warmer the bath, the faster it'll strip the copper. Citric acid is usually available in grocery stores. Make sure to use the correct year pennies... Some will be all copper, some steel, some copperplated zinc.

[lbrewer42]

anything after 1982 is copper-plated zinc. Some 82's are this style - some are the older (mostly) copper style

[westfw]

Does citric acid really etch copper? I guess the big problem is that it'll eat the zinc away too. I don't think I know of anything that will dissolve the copper and stop when it gets to the zinc.

[lasermaster3531]

I think cyanide will but ii is hard to get and toxic.

[ironsmiter]

sorry for the long delays in responding.... Yes, citric acid works well. Not so much etching, as disolving into solution. In my college "small metals" classes, we used a stainless steel tub with a low LP flame burner under it, as a "pickle tank". Mainly to remove the scale from a piece, after soldering. It's effectiveness is llustrated by the nice blue color the liquid developes after a few days use (copper oxide is blue-to-green in color) it takes a while, but I've had students leave their 20-22 gague wire projects in the bath over the weekend, and come back on monday to fid only the heavier gague plate remaining.

[Shark500]

it's simple i just filed off the copper from half of the penny and stuck it into a lemon ... ishould really make an instructible on that. I GOT DIBBS ON IT!

[westfw]

Go for it! Attaching wires to both sides of the coin might be a challenge...

[ironsmiter]

nice :-) To avoid soldering, try artic silver epoxy? and stick the other wire directly into the fruit :-) Classic potatoe clock, except with a higher amperage?

[lemonie]

UK pennies are copper plated steel these days. Concentrated nitric acid will remove copper quite effectively (I've done it, and this is how I know they're steel inside). However, the cell is only going to last as long as the copper-plating

[westfw]

It's the steel/zinc side that gets eaten away. The copper stays relatively unaffected. (at the Zn electrode, the reaction is Zn -> Zn++(aq) + 2e- (and the electronic travel off down the connected wire.) At the Copper electrode, you just have 2e- + 2H+ -> H2 (gas) (electrons from the wire, H+ from the acid electrolyte.) (huh. I spent a bit of time searching, but I didn't find a web page that I thought explained this very well.) The fact that you don't need "substantial" copper is one of the things that makes the copper-plated pennies so interesting...

[lemonie]

Iron and Zinc have different redox potentials, I've not found coins made of zinc. However, I may see what can be done...

[momneedshelp]

Desperate? Yes! 2 multimeters later I still get no readings. What are average results for this if you start with 4 cells and go up 1 by one to 10? Voltage? Current?

[Aeshir]

This is really cool. I'm sure I've seen it somewhere else a buttload of times but I still think so.

Oh and this is a cell, not a battery. At least I think so, correct me if i'm wrong (maybe if each of the coins is a cell on its own).

[gzusphish]

One penny/paper/nickel unit would be a cell. A stack of cells makes a battery.

[ich bin ein pyro]

but if you stacked a bunch of battery cells on top of eachother wouldnt it stil be a cell?

[lasermaster3531]

no. a cell is defined as one positive electrode, one negative electrode, and one electrolyte layer. if you stack many cells in series (pos to neg to pos to neg, etc.) it is known as a battery.

[johnnyappleseed]

How about if we try to relate this information differently. "battery" noun - An array of similar things. When a doctor does a battery of tests, there are multiple different tests, but they are all TESTS, so they are called(collectively) a "battery of tests". A group of "similar" cells is known also as a battery. One of the defining characteristics of any "battery" is a loosely repetitive pattern. The word battery is plural by definition.

[Fiction]

welcome to set theory.

[Brennn10]

Thanks, I changed the title around a bit.

[dadzee]

how many minutes if 5v output would last???????

[acmefixer]

The voltage depends on the load. With a light load the voltage will not drop as much as a heavy load.

Also it seems the output drops with time.  This might be caused by the building up of end products of the chemical reactio.

[pogo13]

how long do they tend to last

[bones288]

Until the juice dries up, however long that takes.

[viper121]

at 6 pennies, nickels i got .85v, as weird as it sounds as I add more pennies, nickels, paper the voltage drops

[lasermaster3531]

try using vinegar or lemon juice. they both work better than salt water. also, you could try sanding some of the copper off one side of the pennies and using that side on the paper. I have gotten 4.5 volts out of 6 pennies/nickles using these methods!

[depotdevoid]

I tried doing this a while back, but couldn't get it to work. Now I see, I wasn't supposed to put paper between all the coins! I'll definitely be trying this at home tonight, thank you!

[knoxarama]

if your doing this in america, this is illegal. while it is legal for the distruction of pennies, you cannot legaly destroy nickles or any other form of currency.

[Ginchi1730]

Negative. Otherwise those penny presses at Disneyland (the ones that press pennies flat and then engrave a copy of Sleeping Beauty's Castle in to it) would be illegal. Who wants to raid Disneyland?

[knoxarama]

no, i said it is legal to destroy pennies. i said it was illegal to destroy the nickles.

[jtobako]

No, it's illegal to MELT DOWN COINS (specifically pennies and nickles) FOR THEIR METAL CONTENT in batches of more than $5. Art projects involving coils are ok. Look it up on the US Mint website.

[knoxarama]

no, a law passed states that specifically pennies can be melted ONLY for their metal content. And i've been to that website. It isn't completely accurate. Also, this isn't an art project, it's a science project. Nickles can't be melted at all.

[jtobako]

As opposed to melting them for???? If you can show me the federal code, I'll believe that the US Mint's guidelines are wrong. Until then, I'll believe that the US Mint knows about US coins : ) And nickles melt at about 2700F : )

[Brennn10]

Where am I destroying or defacing any piece of coinage? This experiment is far from illegal.

[knoxarama]

zinc deteriorates as it is used with acids and copper. This means your are literaly destroying the money. give it time and you will see the damage. I backed this up when i made a lemon juice battery, and the zince rod flaked apart in the juice and disinagrated. and that would be defacing or destroying government property, which with the exception of pennies, is illegal.

[jtobako]

Look up your facts-PENNIES and NICKLES are (were) illegal to melt for metal content because the metal content value exceeded the face value FOR A SHORT PERIOD OF TIME. Copper prices are down, so it's no longer illegal because the mint would make money now where they would have lost money when metal values were higher.