CR4 - The Engineer's Place for News and Discussion ®
Login | Register for Engineering Community (CR4)


Previous in Forum: What is Positive Sequency?   Next in Forum: Induction Motor Design
Close
Close
Close
22 comments
Commentator

Join Date: Mar 2009
Location: Southern California
Posts: 97
Good Answers: 15

Lemon Battery Capacity?

01/12/2011 11:03 PM

Anyone have a guess as to the expected capacity (Amp-hours) of the classic science fair project might be? There's all sorts of websites that show how to make one, and specify the expected voltage, and even in some cases asserting max amperage estimates, but nothing that compares a lemon to a coppertop in terms of capacity. Anyone here ever measure it, or even run one down until it's dead?

Register to Reply
Pathfinder Tags: lemon battery
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19472
Good Answers: 730
#1

Re: Lemon battery capacity?

01/12/2011 11:24 PM

What I wanna know is, if you squeeze all the juice out of a lemon battery, can you still make lemonade with it that would taste any good?

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Power-User

Join Date: Oct 2007
Location: Canning Vale Western Australia.
Posts: 160
Good Answers: 7
#17
In reply to #1

Re: Lemon battery capacity?

01/14/2011 1:12 AM

Have you ever wondered why things that don't work as well as they should are called "Lemons"?

Lemon battery Hmmm?

Good science for kids but not that practical.

__________________
I attend work so my dogs can have the good life.
Register to Reply
3
Guru
Hobbies - Musician - Engineering Fields - Chemical Engineering - New Member Engineering Fields - Control Engineering - New Member Engineering Fields - Instrumentation Engineering - New Member

Join Date: Jan 2007
Location: Moses Lake, WA, USA, Thulcandra - The Silent Planet (C.S. Lewis)
Posts: 3617
Good Answers: 157
#2

Re: Lemon battery capacity?

01/12/2011 11:56 PM

Hi Mitsurati,

Y'know, your very question would make a great project in itself! Make a lemon battery, define a load, take measurements and observations, and publish your findings right here on CR4. That is the essence of experimental science!

Mike

__________________
"Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone." - Ayn Rand
Register to Reply Good Answer (Score 3)
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19472
Good Answers: 730
#3
In reply to #2

Re: Lemon battery capacity?

01/13/2011 12:03 AM

There ya go! Kill two birds with one stone.... Edible/potable experiments are the best.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Commentator

Join Date: Mar 2009
Location: Southern California
Posts: 97
Good Answers: 15
#4
In reply to #3

Re: Lemon battery capacity?

01/13/2011 12:32 AM

I think I may have to just to satisfy my own curiosity. I read somewhere that the lemon-powered digital clock will run for a week, but I don't know what the draw is for that time. If it drew 1 mA for a week, that would be pretty impressive in terms of stored charge. Not sure I want to commit my datalogger for a week, but hey, science of this magnitude is sure to get me that Nobel prize I keep missing out on. The curiosity started with someone's suggestion of harnessing lightning bolts to charge batteries. I ran the numbers, and it seems the average lightning bolt is about 5 Coulombs, whereas a standard AA battery has a charge hundreds of times larger. So I started wondering whether a lemon stores more charge than a lightning bolt. If it can push a milliamp for more than 90 minutes, I'd have confirmation of the hypotheses (anyone want to double-check my numbers?). It would make a great trivia question for the kiddies. I'd let you know how the 'ade tastes, but I'm not real keen on the whole copper poisoning deal!

Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19472
Good Answers: 730
#5
In reply to #4

Re: Lemon battery capacity?

01/13/2011 12:54 AM

At some crude level, energy = volts x amps x time. But as surely you know, most people can scarcely handle one of these variables, let alone two, and much less all three. Hence all the over-unity crap, etc.

I haven't actually run the numbers, but I suspect that a lightning bolt contains more energy than a lemon battery--but not very many order(s) of magnitude more. Hence the value of this as a science-fair project!

I don't remember if copper is a trace dietary necessity; or can you only wear bracelets of it to prevent arthritis? I understand it repels barnacles, and I don't know of any copper-bracelet wearers who have that problem. (But then again, I haven't seen any published research on it.)

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
Hobbies - Musician - Engineering Fields - Chemical Engineering - New Member Engineering Fields - Control Engineering - New Member Engineering Fields - Instrumentation Engineering - New Member

Join Date: Jan 2007
Location: Moses Lake, WA, USA, Thulcandra - The Silent Planet (C.S. Lewis)
Posts: 3617
Good Answers: 157
#7
In reply to #5

Re: Lemon battery capacity?

01/13/2011 1:24 AM

At some crude level, energy = volts x amps x time. But as surely you know, most people can scarcely handle one of these variables, let alone two, and much less all three. Hence all the over-unity crap, etc.

DAMN! Great way of putting it!

If OP is right, we may be in danger of creating a severe lemon shortage. If you don't have lemons, how can you get lemonade? We're doomed!

__________________
"Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone." - Ayn Rand
Register to Reply
2
Guru
Engineering Fields - Electrical Engineering - Analog and Digital Circuit Design Engineering Fields - Electromechanical Engineering - Transformers, Motors & Drives, EM Launchers Engineering Fields - Engineering Physics - Applied Electrical, Optical, and Mechanical

Join Date: Jan 2008
Location: NY
Posts: 1218
Good Answers: 119
#9
In reply to #4

Re: Lemon battery capacity?

01/13/2011 2:09 AM

Never measured one, but the metals are the consumables and capacity should depend mostly on the size of the metal electrodes.

Juggling your estimates and some other ballpark numbers...

AA battery:
2.7 A-Hr = 9720 A-s = 9720 Coulombs
9720 Coulombs * 1.3 V = 12.6 kJ

Lemon battery(?):
1 mA-week * (3600*24*7) s/week = 605 Coulombs
605 Coulombs * 0.90 V = 545 J

Lightning:
100000 A * 50 us = 5 Coulombs
5 Coulombs * 100 MV = 500 MJ

The lemon battery seems to have both less energy and less stored charge than the AA battery. While lighting has the smallest stored charge, it has the largest stored energy by several orders of magnitude.

Register to Reply Good Answer (Score 2)
2
Associate

Join Date: Jan 2009
Location: Poland
Posts: 30
Good Answers: 2
#18
In reply to #9

Re: Lemon battery capacity?

01/14/2011 3:42 AM

Citric acid is also consumed. I found that it is 0.65% of a lemon mass, so it gives (for a 100g lemon) ca 0.0034 mole. So 0.22g of Zn may be dissolved. And it gives ca 330C of charge.

Of course the maximum current is very low (due to very high internal resistance), Voltage at even very small load will certainly drop. Assumption, that all acid will be used is veeery optimistic.

I would guess (still optimistically) 50% of 330C*09.V= ca 150J

Register to Reply Good Answer (Score 2)
Guru

Join Date: Oct 2009
Posts: 1046
Good Answers: 38
#19
In reply to #4

Re: Lemon battery capacity?

01/14/2011 8:39 AM

"I ran the numbers, and it seems the average lightning bolt is about 5 Coulombs"

This site:
http://peswiki.com/index.php/Directory:Lightning_Power#Harnessing_Lightning_Power

gives an estimate for a single strike is "1 Mv 100 amps for 20 msec" and suggests a step-down transformer to convert this to 10V 10 MA for 20 msec. I suspect the original 1MV is actually at the the top of the strike, and that the voltage at the transformer primary might be only 1kV, but even so I suspect that the coulombage of the lightning bolt is considerably more than 5.

Register to Reply
Commentator

Join Date: Apr 2010
Location: Moncks Corner, South Carolina, USA
Posts: 86
Good Answers: 3
#21
In reply to #4

Re: Lemon battery capacity?

01/14/2011 1:56 PM

You might get the Nobel Prize just for planning on performing the experiement.

__________________
You can always tell a Nuke because you can't tell him anything!
Register to Reply Off Topic (Score 5)
Anonymous Poster
#14
In reply to #3

Re: Lemon battery capacity?

01/13/2011 10:37 PM

No way . . . It is just not feasible in view of processing cost and economical commercial value of their finished product and by product too!

Register to Reply
Guru
Australia - Member - New Member

Join Date: Feb 2008
Location: Australia
Posts: 1677
Good Answers: 196
#6

Re: Lemon battery capacity?

01/13/2011 1:19 AM

This has REALLY got me thinking. I have a lemon tree near my front gate.What if I create the lemon battery while it's still on the tree???

Would that power an LED light source for the gate?

Would it automatically recharge each day by photosynthesis?

Sounds like a fun experiment if I'm prepared to risk the tree.

I'm tempted to buy a tree from the nursery just to try this.

Would make an interesting addition to the home.

__________________
Just an Engineer from the land down under.
Register to Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 19472
Good Answers: 730
#8
In reply to #6

Re: Lemon battery capacity?

01/13/2011 1:49 AM

If the lemons remain on the tree, maybe they will never run out, until the sun runs out. That could be long-lasting, even if not perpetual. I bet it never reaches commercial scale, though.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru

Join Date: Feb 2009
Location: West Coxsackie, NY
Posts: 536
Good Answers: 10
#16
In reply to #6

Re: Lemon battery capacity?

01/13/2011 11:37 PM

Go for it on your existing lemon tree. Add a couple electrodes and see if it will light a few LED's

Let us know how the light and duration is.

__________________
"Real Bass Players" do not use picks
Register to Reply
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5168
Good Answers: 263
#10

Re: Lemon Battery Capacity?

01/13/2011 1:37 PM

1 lemon = 0.83V x 0.00015 Amps = 0.0001245 Watts

source

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

Then again wouldn't that capacity change with type of lemon are we talking Eureka, Lisbon, Meyer

Even the growing season and local

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply
Power-User

Join Date: Mar 2009
Location: Mid-West Ontario.
Posts: 148
Good Answers: 5
#11

Re: Lemon Battery Capacity?

01/13/2011 1:59 PM

This brings back memories! This was my science project in Grade 7 and I called it "SOUR POWER"

This would have been in 1982 or 83. At the time I was limited to cool electronic devices to power such as LED's and Digital clocks. All I had to work with was a "150 in 1 Science project kit" http://www.flickr.com/photos/chrisglass/285081870/ . I tried several build projects with it such as a radio beep noises and lights but the only thing I could get to work was the "Big Ear" which was a hearing aid. Also I did a bit of D of E with alloys and I think I ended up using a galvanised nail and a penny. As for life expectancy I think it worked well for a week until it started to decay as a new lemon would be more acidic.

Josh.

__________________
~Good Judgement comes from experience... and a lot of that comes from Bad Judgement! ~The Early bird may get the worm.. But the second mouse gets the cheese!
Register to Reply
2
Guru
United States - Member - New Member Engineering Fields - Power Engineering - New Member

Join Date: Sep 2006
Location: California, USA, where the Godless live next door to God.
Posts: 4295
Good Answers: 698
#12

Re: Lemon Battery Capacity?

01/13/2011 3:41 PM

As to the LED gate lighting: from the same Wiki page.

LED bulb = 2.8V x 0.0006 Amps = 0.000498 Watts, or four lemons. I have a VERY prolific Meyer lemon tree in the front of my house, I can't possibly use all the lemons I get from it and my neighbors lock their doors and hide when they see me approach with a bag in my hands. This would be fun!

The juice would be toxic after use, zinc and copper oxides would be dissolved in it.

Photosynthesis would not "recharge" the battery. The acidity is the result of the lemon ripening. Once ripe, it is no longer growing, it is beginning to rot until it falls off the tree to provide fertilizer for the seeds inside (remember what the lemon TREE is growing the lemons for). So once the lemon is ripe enough to be a 'battery", the tree is already done with it.

__________________
** All I every really wanted to be, was... A LUMBERJACK!.**
Register to Reply Good Answer (Score 2)
Associate

Join Date: Jul 2008
Location: Norfolk, VA
Posts: 50
Good Answers: 4
#20
In reply to #12

Re: Lemon Battery Capacity?

01/14/2011 11:06 AM

Not zinc and copper oxides - one of them has to be the cathode...

Register to Reply
Guru

Join Date: Jul 2008
Posts: 1203
Good Answers: 102
#13

Re: Lemon Battery Capacity?

01/13/2011 5:39 PM

The guys that run microcontroller boards at trade shows using lemon power usually end up adding a little water to the nail holes to keep it running all day. I don't know how much of that is due to the lemon drying out and how much is due to trade show people touching the lemon and squeezing out a little juice.

Often the trade show people will also pull out the nails/wires and move them into a new hole. Once again, I don't know if this is because they got all the electrical energy out of the previous cells (biologically speaking) or if it is because the hole was drying out.

So, your little experiment needs to define:

  • Is it legal/desirable/beneficial to move the nails/wires?
  • Is it legal/desirable/beneficial to add more water to the hole?

Also, if you have one lemon do you have one battery cell or millions?

__________________
Few things limit our potential as much as knowing answers and setting aside questions.
Register to Reply
Power-User

Join Date: Jun 2007
Location: Center of the Known Industrial Universe - TUGGERAH 2259 - Australia
Posts: 180
Good Answers: 24
#15

Re: Lemon Battery Capacity?

01/13/2011 11:18 PM

Hmmm, slice the lemon, use the correct foil electrodes between layers, instead of a single cell you could have a higher voltage battery. Can't do this on the tree, folks!

0.83 volts per slice, maybe 11 slices per lemon, you could probably power a smoke alarm with a single sliced lemon. No, wait, the fire would dry out the lemon.

Mark Bingham
Relativity PL

Register to Reply
Guru

Join Date: Jun 2009
Location: Bangalore, India
Posts: 729
Good Answers: 24
#22

Re: Lemon Battery Capacity?

01/15/2011 11:12 AM

Capacity is a function of the mass of anode material dissolved. Bioramani

__________________
bioramani
Register to Reply
Register to Reply 22 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); bioramani (1); BruceFlorida (1); Doggoneit (1); jgjengr (1); Jimh77 (1); JRaef (1); Just an Engineer (1); kajot (1); Mikerho (2); Mitsurati (1); mjb1962853 (1); ozzb (1); Part time thinker (1); phph001 (1); Relativity PL (1); Tornado (4); XNuke (1)

Previous in Forum: What is Positive Sequency?   Next in Forum: Induction Motor Design

Advertisement