🚀 go-pugleaf

Organization : California Institute of Technology
Keywords: 
From: fritz@polecat.Caltech.Edu (Fritz Nordby)
Path: polecat!fritz

In article <4@chasefrs.UUCP>, saul@chasefrs.UUCP (Saul Goldfisher) writes:
> I am trying to build a homemade battery for my daughter's science project
> using multiple lemons with copper and aluminum plates.  After connecting
> 12 lemons I can get 2.2 volts but not enough amperage to light a 1.2v
> 2.2 mA bulb.  Any suggestions on how to improve the amperage output?

As almost everyone who has responded has said, zinc will work better than
aluminum; the zinc-aluminum potential is ~0.9V, I think.

As almost everyone who has responded has said, you can increase the current
by putting several of the home-made batteries in parallel.

What nobody has said yet is that you can use electrolytes other than citric
acid.  When a local kid came asking for help on his science project, we set
about making a bunch of batteries out of a plate of assorted fresh fruit and
a bunch of copper and zinc strips; once we had worked our way through a wide
variety of fruits and vegetables (including grapefruit, oranges, lemons,
apples, potatoes, ...), we started adding cups of coffee and tea, and anything
else we could think of with a significant acidic component -- and they all
worked, all producing the same ~0.9 V.  The result was a quite spectacular
display in class, and a slight cry of dismay followed by a look of amazement
from the teacher as her cup of coffee was turned into a battery before her
very eyes (that kid always did have a flair for the dramatic)!

		Fritz Nordby.	fritz@vlsi.caltech.edu	cit-vax!fritz