saul@chasefrs.UUCP (Saul Goldfisher) (01/14/87)
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? Saul Goldfisher (212)-676-0851
barker@ems.UUCP (Bob W. Barker) (01/16/87)
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? > >Saul Goldfisher (212)-676-0851 It sounds like you're going to have to put more fruit in parallel with what you've got now! Another possibility would be to hide a couple of AA batteries in one of the lemons :-). I wonder if grape fruit, limes or any other type of fruit would work better than lemons?
apn@nonvon.UUCP (01/16/87)
in article <4@chasefrs.UUCP>, saul@chasefrs.UUCP (Saul Goldfisher) says: > > 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? > > Saul Goldfisher (212)-676-0851 a few ideas: 1) increase surface area of plates more sureface area = more current 2) switch to a lower current light.... It may be possible to find an LED that will light with 0.2 or mA... however the voltage drop will be more. Try hewlett packard optoelectronic products... good stuff 3) pick more dissimiliar metals maybe Zinc and Copper 4) pick more acidic lemons Alex UUCP: ihnp4!ptsfa!nonvon!apn {* Only those who attempt the absurd ... will achieve the impossible *} {* I think... I think it's in my basement... Let me go upstairs and check. *} {* -escher *} -- Alex P Novickis UUCP: ihnp4!ptsfa!nonvon!apn {* Only those who attempt the absurd ... will achieve the impossible *} {* I think... I think it's in my basement... Let me go upstairs and check. *} {* -escher *}
ron@brl-sem.ARPA (Ron Natalie <ron>) (01/16/87)
In article <4@chasefrs.UUCP>, saul@chasefrs.UUCP (Saul Goldfisher) writes: > 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? > Hook up more lemons in parallel.
larry@kitty.UUCP (Larry Lippman) (01/16/87)
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? Use copper with zinc, and forget the aluminum. I realize that finding pure zinc in the household environment may be difficult, so try using a piece of galvanized sheetmetal. Increase amperage by increasing electrode surface area (bend into a semicircle is one possibility). Also, connect lemons in parallel. We won't talk about adding a depolarizer... :-) <> Larry Lippman @ Recognition Research Corp., Clarence, New York <> UUCP: {allegra|bbncca|decvax|nike|rocksanne|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231 {hplabs|ihnp4|mtune|seismo|utzoo}!/ <> FAX: 716/741-9635 {G1,G2,G3 modes} "Have you hugged your cat today?"
wsr@lmi-angel.UUCP (Wolfgang Rupprecht) (01/16/87)
In article <> 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? It sounds like you need the new heftier D-size lemons. :-) Seriously, you should try to put lots of lemmons in parallel, to increase the maximum currant capability. Use as wide a set of plates as possible. Perhaps you might be willing to substitute a 100 uA meter movement for your 2.2 mA bulb. It would certainly be easier to drive. If all else fails, you could always hide a small hearing aid battery in one of the lemons. :-) -- Wolfgang Rupprecht {harvard|decvax!cca|mit-eddie}!lmi-angel!wsr
koko@uthub.toronto.edu (M. Kokodyniak) (01/16/87)
> 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? > > Saul Goldfisher (212)-676-0851 Yes. Get alot of lemons! (But be sure to buy them wholesale.)
chas@prism.UUCP (01/16/87)
Have you tried another dozen in parallel? ------ chas@mirror.TMC.COM ------
greg@utcsri.UUCP (Gregory Smith) (01/16/87)
In article <585@brl-sem.ARPA> ron@brl-sem.ARPA (Ron Natalie <ron>) writes: >In article <4@chasefrs.UUCP>, saul@chasefrs.UUCP (Saul Goldfisher) writes: >> 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? >> >Hook up more lemons in parallel. Before you do that, try increasing the effective surface used in each lemon. Use Copper and Al plates that are as large as will conveniently fit in the lemon. Even better, shove in 3 or 4 of each, spacing them evenly and alternating copper and aluminum. Then wire all the Al together to form one pole and all the Cu together to form the other. If you have 4 of each, you will have created seven cells which use the area on both sides of most of the plates ( the ends are not used ). These seven cells are wired in parallel. You will also get a much greater CFUF ( Citrus Fruit Utilization Factor) using this method. -- ---------------------------------------------------------------------- Greg Smith University of Toronto UUCP: ..utzoo!utcsri!greg Have vAX, will hack...
bl@hplabsb.UUCP (01/16/87)
In article <1541@kitty.UUCP>, larry@kitty.UUCP (Larry Lippman) writes: > 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? > > Use copper with zinc, and forget the aluminum. I realize that > finding pure zinc in the household environment may be difficult, so try > using a piece of galvanized sheetmetal. A possible household source of zinc are pennies. The modern ones are zinc plated with a copper alloy. Try scraping or sanding off the copper plating. I haven't tried this myself, but it should work. Good luck. BTW, pure zinc can be obtained at any boating supply store. Zinc slugs are used as annodes to help prevent corrosion. Also, iron may work in place of the zinc. Try a nail.
roy@phri.UUCP (01/17/87)
In article <4@chasefrs.UUCP> saul@chasefrs.UUCP (Saul Goldfisher) writes: > 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? Easy -- use bigger lemons! This is not as stupid as it sounds; the voltage of each cell is a function of the electrochemical potential difference between the two metal electrodes (I think this is typically done with zinc and copper strips; but I guess aluminum is easier to find). The maximum current will be mostly a function of the internal resistance of the electrolyte (the lemon). A bigger lemon will have a lower internal resistance so it will give you more current. Using wider metal strips may help as well. I suppose using something like a grapefruit might help because it's bigger than a lemon, but I don't know how the resistivity (resistance per unit volume) of a lemon and a grapefruit compare. BTW, cooks have a trick for getting more juice out of a lemon. You roll the lemon around on a table under the palm of your hand; this breaks open the internal membranes, making it easier to squeze more juice out of it. This might help get more electrical "juice" out of the fruit as well. The straight-forward way, of course, is to just hook up a bunch of lemons in series-parallel. More in series; higher voltage. More in parallel; higher current capacity. If all else fails, try hiding some Ni-Cads in each lemon. :-) -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016 "you can't spell deoxyribonucleic without unix!"
yerazuws@rpics.UUCP (01/17/87)
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? 1) Warm the lemons. 2) roll them before puncturing to 1) break up the internal structure and 2) release more of the acidic juices. 3) Put the electrodes close to each other (but not touching) to decrease the internal impedance of the lemon battery. 4) DON'T use aluminum for the + electrode. Aluminum very easily forms the tightly adherent Al2O3 oxide layer- which is an electrical insulator. That's probably why you can't get enough amps (more than any other factor). Try any other metal- like iron, or maybe even zinc (a new US penny is zinc-cored... so if you can get the copper plating off, there you go. Or use a galvanized roofing nail- it's steel dipped in molten zinc.) 5) Steel-wool your electrodes right before use, to remove any insulating oxides/skin oils. Twelve lemons?!?! That's enough to jump-start a car! I guess your daughter's science project is an arc welder. :-) -Bill Yerazunis "Don't try this at home, kids"
grr@cbmvax.cbm.UUCP (George Robbins) (01/17/87)
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? > >Saul Goldfisher (212)-676-0851 1) use electrodes with as much area as possible 2) use steel wool or scotchbrite to remove surface oxide from the aluminum 3) keep the plates close together - maybe in the same hole seperated by a piece of paper towel 4) try zinc instead of aluminum I would also try using one of those solar cell motors rather than trying to light a bulb. It should give some visible action on just a little current, and keep running once it gets started while the light bulb will probably start to dim as the plates gas up. Rubbing the plates with some maganese dioxide from a cheap flashlight battery *might* help reduce the gassing. -- George Robbins - now working for, uucp: {ihnp4|seismo|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@seismo.css.GOV Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
ornitz@kodak.UUCP (barry ornitz) (01/18/87)
From a table of the Electromotive Series, the copper-aluminum couple should
give quite a bit more voltage than indicated. Probably what is happening
is caused by the oxide coating found on all aluminum. The acidity of the
lemon is possibly not high enough to dissolve this oxide layer. Zinc would
be a good choice, iron would be relatively poor. Zinc is easy to find
around the home. Cut open any ordinary flashlight battery, i.e. carbon-zinc.
Throw away the carbon electrode, scrape out the manganese dioxide depolarizer,
and keep the zinc shell. Sand it well before using in the lemon. Also don't
eat the lemons after the experiment; the metallic taste could be poisonous!
BTW, my knowledge of this comes from information on corrosion protection.
Eastman Chemicals Division is not involved with Kodak's new battery business.
I do know for a fact that the new batteries are not based on lemon technology;
however, how do you explain the lemon's yellow color? :-)
Barry L. Ornitz
Eastman Chemicals Division Research
Kingsport, TN 37664
Standard disclaimers apply.news@cit-vax.Caltech.Edu (Usenet netnews) (01/18/87)
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
ken@rochester.ARPA (SKY) (01/18/87)
|>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? Nobody has mentioned this but I know of no bulb that runs on 2.2 mA. Maybe you meant 22 mA? Why not use a LED? You might need two cells in series though. I would also give up Al because of the oxide layer. Ken
ken@argus.UUCP (01/19/87)
In article <1541@kitty.UUCP>, larry@kitty.UUCP (Larry Lippman) writes: > 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? > Use copper with zinc, and forget the aluminum. I realize that > finding pure zinc in the household environment may be difficult, so try > using a piece of galvanized sheetmetal. > <> Larry Lippman @ Recognition Research Corp., Clarence, New York No it isn't, if your willing to cheat: go buy a dozen of the cheapest carbon-zinc batteries you can find, and take a hacksaw to the casing. The casing you find inside is zinc. It's been many years since I've taken this apart as a kid, but I remember the operation is a mess. I don't recall any hazard, but I used kitchen gloves to handle the stuff just in case. -- Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102 uucp !ihnp4!allegra!bellcore!argus!ken *** WARNING: NOT ken@bellcore.uucp *** bitnet(prefered) ken@orion.bitnet Gillian: "Are you sure you won't change your mind?" Spock: "Is there something wrong with the one I have?"
levy@ttrdc.UUCP (01/19/87)
In article <1520@cit-vax.Caltech.Edu>, news@cit-vax.UUCP writes: >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.... To get more current out, you could also try decreasing the distance between anode and cathode plates as much as possible without actually letting them touch (decrease internal resistance). You could even make a kind of "voltaic pile" with thin lemon slices sandwiched between back-to-back zinc-aluminum plates. This would give you considerable "juice" (pardon the pun) in a small package without having to waste a lot of lemons. Keep neighboring lemon slices and plate-pairs from touching or else power will be lost and corrosion will quickly occur from the "short circuit." + | ZnZnZnZn LEMON SLICE AlAlAlAl .... ZnZnZnZn LEMON SLICE AlAlAlAl | - -- ------------------------------- Disclaimer: The views contained herein are | dan levy | my own and are not at all those of my em- | an engihacker @ | ployer or the administrator of any computer | at&t computer systems division | upon which I may hack. | skokie, illinois | -------------------------------- Path: ..!{akgua,homxb,ihnp4,ltuxa,mvuxa, allegra,ulysses,vax135}!ttrdc!levy
pozar@hoptoad.uucp (Tim Pozar) (01/19/87)
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? > Use oranges. :^)
artm@phred.UUCP (01/19/87)
If the federales are following this, I can see it coming:
A new CPSC regulation requiring labels that say "WARNING! Lemon
may explode if recharged or disposed of in fire"...
==============================================================================
Ain't no opinions here!
==============================================================================
Art Marriott tim@ism780c.UUCP (Tim Smith) (01/20/87)
Whatever you do, don't use salt water between the two metals! A friend
of mine made a battery this way once, and I touched the electrodes.
Then the police came and took me away.
They said I was charged with a salted battery.
--
Religion: just say "no"
Tim Smith USENET: sdcrdcf!ism780c!tim Compuserve: 72257,3706
Delphi or GEnie: mnementhdbb@aicchi.UUCP (Burch) (01/20/87)
If you give the lemon a good soild smash before inserting the electrodes, the amperage should go up. This breaks the cells, and lets you have more electrolyte to work with. -- -David B. (Ben) Burch Analysts International Corp. Chicago Branch (ihnp4!aicchi!dbb) "Argue for your limitations, and they are yours"
idall@augean.OZ (Ian Dall) (01/21/87)
In article <114@ems.UUCP> barker@ems.UUCP (Bob W. Barker) writes: >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? >> >>Saul Goldfisher (212)-676-0851 > >It sounds like you're going to have to put more fruit in parallel with >what you've got now! Another possibility would be to hide a couple of >AA batteries in one of the lemons :-). I wonder if grape fruit, limes or >any other type of fruit would work better than lemons? Anything which reduces the internal resistance will help. I don't know if aluminium is very suitable - it's oxide layer may be a problem - zinc is a traditional electrode. Also place the electrodes as close together as possible without touching.