Naked Science Forum

Non Life Sciences => Technology => Topic started by: Sahil Kumar on 15/07/2008 10:03:04

Title: How do you make a lemon-powered iPod?
Post by: Sahil Kumar on 15/07/2008 10:03:04

Sahil Kumar asked the Naked Scientists:

Hello again, you may recall me e-mailing you on the topic of a science
project for school, well I've chosen long ago and I picked the lemon
powered mp3 player; only problem is I can't make much sense of it.

If it isn't too much trouble can you tell me how all the wires go or send me an image of how you did it. I asked my teacher and he said something about parallel circuitry but I'm not the brightest and i don't have an idea of what he's talking about.

Once again I love the show (http://www.thenakedscientists.com/HTML/podcasts/) and think it's awesome.

regards
Sahil.

What do you think?

Title: How do you make a lemon-powered iPod?
Post by: RD on 18/07/2008 00:16:42

You'll need a lot of lemons to power an i-pod ...

Quote

A lemon cell battery is made with a lemon and two metallic electrodes of different metals such as a copper penny or a copper plating and a galvanized (zinc coated) nail. In practice, a single lemon cell is incapable of lighting a light bulb; one would need about 500 lemons but wired in parallel to light a standard flashlight bulb.

http://en.wikipedia.org/wiki/Lemon_battery

500 lemons is pessimistic, 10-20 could power an MP3 player.  

Or a similar number of tins of cat-food... 

Quote

It's possible to make a battery using cat food! To do this, open the tin preferably without the cat being near otherwise it'll expect to be fed. Put a fork into the middle of the food so the fork stands up and doesn't touch the can. Now there is a voltage between the fork and the tin can. This is because the fork and the can are made of different metals and the cat food becomes an electrolyte and conducts electricity to some extent. The amount of electricity generated by a catfood battery is not great and won't light a bulb, but it is measurable and will drive "solar" motors.

http://www.zyra.org.uk/battery.htm


1 - 3  lemons / tins of catfood should be be sufficient to power an LCD clock (http://familyfun.go.com/parenting/learn/activities/feature/famf119weirdsci/famf119weirdsci6.html) or calculator (http://www.sciencebuddies.org/mentoring/project_ideas/Elec_p029.shtml)

The voltage derived depends on the type of metals used as electrodes.

A battery can be made from a pile of coins...
http://www.sciencebuddies.com/science-fair-projects/project_ideas/Phys_p063.shtml?from=Home