Jan 30, 2007
Potato Powered mp3 Player - Not!
Fed up with using up so many batteries? Rechargeables giving you poor mileage? Then why not try a couple of sweet potatoes instead.
In this “video tutorial”, you’ll learn how to use a couple of galvanized (zinc coated) nails, some bare copper wire, a pair of mini crocodile clips, AND two sweet potatoes, to power up your mp3 player with not a conventional battery in sight. Great video and the music’s sweet too.
The Hole - video powered by Metacafe
This appliance is, of course, closely related to the lemon battery (or more formally lemon cell) familiar to anyone who’s searched for a high school science project. Two different metallic objects dipped into a conduction solution (an electrolyte) will produce an electrochemical reaction the byproduct of which is electricity. A single lemon is usually enough to illuminate a flashlight bulb, but two sweet potatoes are apparently required for an mp3 player. Yes, it reduces the portability of your player, but just think…no more buying batteries! Of course, things might get a bit smelly as those sweet potatoes (Ipomoea batatas) start to go off.
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bob the frog said,
February 2, 2007 at 1:42 am
Of course the zinc gets used up which costs loads of energy to produce and the sweet potato is somewhat irrelevant (any conductive solution would work as well) but apart from that it’s solid science.
David Bradley said,
February 2, 2007 at 9:59 am
Yes, if only we had a magic porridge pot of zinc!
Amnon said,
February 5, 2007 at 4:54 pm
Are the potatoes connected ?
David Bradley said,
February 5, 2007 at 6:01 pm
Thank goodness, someone has finally spotted the con. This approach to power generation is of course a conjuring trick. There is no circuit. So, how could it possibly power up the mp3 player. To stand a chance of it working, would be to insert the copper wire directly into the potato and connect it to one battery terminal and the other terminal would lead to the zinc-coated nail embedded in the *same* potato. electricity could then flow through the electrolytic solution (the salty contents of the potato) closing the circuit. Whether or not this kind of electrochemical cell would generate enough power to run the mp3 player (which usually requires 2 AA batteries, 3 volts, in other words) and the speakers is a different matter…
mudzilla said,
February 7, 2007 at 2:52 pm
that is very cool can you send me one for free now. there is acid in those taters.
cory rizzo said,
February 20, 2007 at 9:15 pm
me the fool tryed to do this for my 11 year old son of course it did not work.is there any other way it will work to power a mp3 player getting 1.6 on my voltmeter when they are wired the proper way but still wont power the mp3 the mp3 takes 1 aaa can anyone help with this project
Father seek of help
David Bradley said,
February 21, 2007 at 8:05 am
Like I said in an earlier comment, you have to use the zinc-coated nail and the copper wires as the electrodes. Each embedded a conducting media (whether a lemon, or electrolyte solution. Here’s another video showing that you can get just over one volt from a single battery. So you might need one and a half to power your mp3 player. Actually that’s also a little joke, one and a half lemons would give you just over two volts, the size of lemon is irrelevant, it’s the copper and zinc that matter.
Robert Keating said,
February 23, 2007 at 12:44 pm
A single lemon is usually enough to illuminate a flashlight bulb, but two sweet potatoes are apparently required for an mp3 player. Yes, it reduces the portability of your player, but just think…no more buying batteries! Of course, things might get a bit smelly as those sweet potatoes (Ipomoea batatas) start to go off…
David Bradley said,
February 23, 2007 at 3:33 pm
You don’t even need a single lemon. The lemon in the standard high-school demo is really just there for dramatic effect - light up a bulb with a lemon, who’s going to forget that in a hurry. All you really need is a conducting solution into which to place the two electrodes. It is the difference in relative energy of the metals that provides the potential gradient, the electrolyte simply acts as a medium for the transfer of electrons to complete a circuit that can do work. You would still be able to light the bulb with half, quarter, eighth or smaller chunk of lemon so long as you could insert the electrodes without them coming into contact with each other.
As was mentioned earlier this sweet potato demonstration is a spoof. It won’t work with one, two or even a million potatoes wired up like this. Wire it up properly though and the conducting solution within a single yam would be enough to carry the current and power the mp3 player.
David Bradley said,
May 10, 2007 at 3:12 pm
Because of the repeated mention of the “word” mp3 in this post, it gets quite a significant proportion of the comment spam on sciencebase.com. 99.999% of it is picked up by our spam filters and dumped, but one such spam comment almost slipped through. Said comment was pointing to a site calling itself googlemp3. It exists as of May 5, but I suspect site registrant Duanne J will receive a note from Google’s lawyers any day now, unless of course he works for Google, in which case Google itself will get a call from the RIAA.
pepeschneider said,
September 25, 2007 at 5:13 pm
The whole thing is a***fake*** !!! As David Bradley already said on Feb 5 2007 , to get even a minimum chance, you had to put both the copper and the zinc in the same potato. You would get a voltage of about 0.8V. Much to little even to operate a mp3-player that is usually driven by a single battery with 1.5V. Besides this fact, the current that this potato-battery provides is much too low to operate a player. To double the voltage, you could work with two potatoes, each equipped with one copper and one zinc. The copper from one potato would then be connected to the zinc from the other one. this would give around 1.5V.
Even then, the problem with the low current remains. If this wasn’t enough, to pretend to operate two speakers with the same - non-working! - battery is really ridiculous.
The whole thing has the potential to become one of the most stupid internet-fakes I’ve ever heard.
Here in Germany the science-magazine of the German TV has this thing on his internet-page. This only shows, that tv-makers are the same bunch of stupids everywhere in the world.
David Bradley said,
September 25, 2007 at 6:33 pm
It’s probably possible that you could boot up the mp3 player chip and screen with 0.8V but almost certainly couldn’t drive a couple of speakers.
latasha said,
December 14, 2007 at 1:01 am
where can you get the crocodile clips and the lil wire that go thro
David Bradley said,
December 14, 2007 at 7:30 am
Radio Shack, perhaps? But, don’t follow this video it’s a spoof. Read the comments to see how it is really done.
David Bradley said,
December 17, 2007 at 11:24 am
I saw a very similar video showing how to charge an iPod with an onion. It was brilliantly done but basically amounted to shoving the USB cable into the onion. There were lots of follow-ups showing how this could not possibly work and that the voltage you get from such an act is negligible.
db
DAVID said,
March 12, 2008 at 7:14 pm
How will this work? My son is trying to do this for a science project and it’s not working. We’ve tried it the above way and by linking both sweet potatoes together and nothing. I’ve also tried it with 3 potatoes linked together and again nothing. Can anyone help? He needs this ASAP. Thanks David
David Bradley said,
March 12, 2008 at 7:49 pm
IT DOES NOT WORK!!! It’s a spoof, as mentioned earlier.
Check out the lemon battery post that DOES WORK!!!
db
David Bradley said,
May 1, 2008 at 2:50 pm
I forgot to add a comment to this to let readers know that I posted a more legitimate fruity battery item recently - Lemon Battery. Anyone given it a try and had success, leave a comment to let us know? Have you used anything more exotic than a lemon to generate an electrical current?
db