Introduction: The Tiny Lemon Battery, and Other Designs for Zero Cost Electricity and Led Light Without Batteries

About: I love designing cool gadgets... I'm also Founder at Lumi Industries where we design awesome 3D Printers and Holographic displays!
Hi, you probably already know about lemon batteries or bio-batteries.
They are used normally for educational purposes and they use electrochemical reactions that generate low voltages, usually shown in the form of a led or light bulb glowing.

These batteries usually use 3-4 lemons to barely light up a led.
Good designed ones use just one lemon, but are still very limited and I never show breakthrougs or innovations in the design.

I'd like to share with you some of my designs for something different.

They use a few DROPS of lemon juice. The Smallest uses just 1 DROP, and you have to look carefully to see it with naked eye, and still you can build it in a few minutes with scrap materials.

The lightest weights half a gram - 0.5g.

They light up a 3.5V, 35mA white Led for at least 1 hour.

After 1 hours (more or less depending on climate) the lemon juice evaporates.
It is like a natural timer. If you want more light, just put other drops of lemon juice.

These cells can be re-used for many, many times before oxidizing makes it unusable.

Now I'm showing how to make in less than 10 minutes some of my Lemon battery designs, all with scrap materials you have around house and zero cost.

We will make the Smallest lemon battery first. They are REALLY small. And they work! Try by making one yourself.

After that I'll introduce you to the flower lemon battery design, in which you light up the led by watering the flower (with drops of lemon juice).

Finally, we will see other different designs for making a battery out of ordinary materials.

I hope you will enjoy them.
A little step toward being green will be you using these designs instead of buying a battery to light a led or to make an emergency flashlight ;)

You will be able to make light out of almost every material, and you shalt never be in the darkness anymore ;)

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Step 1: The Flower Lemon Battery

This can also be a very original gift.
Give it to your special one, bring her and the flower in quite darkness, then give her half a lemon (or lemon juice in a nice tiny cup if you feel more elegant) and ask her to water the flower.
Success guaranteed ;)

Step 2: The Flower Lemon Battery, Better Design

The flower lemon lamp!

Same idea as before, but many improvement.

18 cells, 3 yellow leds, for the flower.
1 green led for the leaf.

Tools: scissors, glue gun, paper, copper and zin wire.

More details will come soon...

Step 3: Materials

Ok, Let's start. We will make now the Tiny Lemon Battery with led, design 1.

Very basic materials you will need, you should have more or less all of them around house and you can use pieces that would have been wasted otherwise, like a lemon cut some days ago, piecese of scrap wire metal, pieces of unused copper wire.
Here we are:

-Zinc plated iron wire, 0.8mm section i use, but this is not important;
-Some pieces of copper wire;
-A Lemon
-One paper facial tissue or a sheet of absorbing paper
-A Led


- A Solder,
- Scissors, those that you can use to cut 0.8mm metal wire

Step 4: How It Works

This battery is a zinc-copper battery. Searching with google or wikipedia will give you exact explanation of the electrochemical reactions involved, but here, we'll just see how to realize it.

This battery is made up of 4 mini cells. Each cell will provide about 0,9 volts.
They will be linked in series to achieve at least 3.5v that is necessary for the led to light up.

Each cell si essentially this:

-a 0.8mm section, 1cm long piece of iron wire zinc plated, acting as anode;

-a layer of absorbing paper, with a drop of lemon juice, acting as a salt bridge, wrapped around the iron wire;

-copper wire wrapped around the paper, carefully not to touch the iron directly.

Step 5: How to Make the Cells

Cut about 1.5 cm of Iron wire.

Take one paper facial tissue and carefully extract one of the 3 or 4 layers that compose the tissue.
(The thinner, the better).

Cut a a rectangle 2 cm long and 1cm wide.

Roll the 2x1 cm rectangle cut out of the layer around it the iron wire.
Make sure to left space, about 5 mm, uncovered.

Cut a piece of copper wire about 10 cm long.
Extract the thin copper wire strands removing the insulating plastic around.

Finally, wrap around the copper wire strands around the paper, making sure it doesn't touch the iron directly.

Here, you just have made one cell.

Now just make 4 of them and solder them is series.
(That means, solder the copper tail of one cell to the exposed iron wire of the next one)

I put them alternately to minimize the overall size.

Step 6: Done!

Solder the 4 cell in series to the led, respecting polarity according to the scheme.

Put 1 drop of lemon juice on each cell.

And voila', enjoy one hour of free light ;)

Here are some considerations about this battery design:
-wire the copper strands very close together for better results;
-if you enclose the whole battery to reduce evaporation, the led will light for longer time.

Next I am showing you my tiny reasearch on Volta's batteries.
We will see 10 different designs, each one with its pro and cons.

PS: if you liked this instructable, please vote it for the Epilog Challenge ;)

Step 7: The Lemon Crab

In this design the cool thing is that the legs and claws of the crab are the battery.
This is used to light the crab's eyes.

It means that to make the eyes of the crab glow, you just have to squeeze a few lemon drops on each leg and claw of the crab ;)

In the detail, each leg/claw/cell is a 1 cm long piece of zinc wire, with a tiny strip of paper towel around it and a smaller strip of copper foil around the paper. It's a simple electrochemical cell activated when you drop a lemon juice drop on it and the paper becomes wet, because it becomes the electrolyte and electrons can flow through it.

Each cell generates about 0,7 V. There are 8 cells, and they are connected in series, 4 of them for each led.

Step 8: The MICRO Lemon Battery

This is by far the smallest lemon battery at all. I came to this design wondering how can I redce the size and still have a lemon battery capable of making a led glow and still using very poor materials from scrap or household junk ;)

It is made by 4 micro cells.

Each one is a 0,4 mm long piece of zinc wire, with some tissue paper around it, and a tiny piece of copper around the paper.

The cells are put in series and soldered directly on the pins of the Led.

A drop of lemon juice will activate it for an hour. make sure that with this size the paper of one cell doesn't touch the paper of another one.

I have included two views from a 3d cad, for better reference on how to assembly it.
Purple balls are showing where you have to solder.

Step 9: Other Designs_1: the Long Lasting

Here we make a battery trying to maximize duration and portability, that is quite solid too.
Also good looking and green ;)


Each cell is contained in these small boxes I have found perfect for this purpose, and good looking too. These boxes are sold with extra leads for drawing compass (actually, you buy the extra leads, and you get these wonderful boxes for free)

Other materials you need are:

-Copper wire
-Zinc (you can get it from an art shop beacus it is used in 10x15cm sheets for carving)
-Some wire and solder
-a Led
-Sunlight(R) Active Gel Lime hand dish washing liquid, any brand would work, Gel instead of liquid will last longer, and green color is my personal choice ;)

Step 10: Other Designs_2: the Straw Battery

Basically, each cell is made up of a spiral of copper wire, another spiral of zinc-plated iron wire, inside a transparent straw filled with hand dish washing liquid, and sealed with hot glue.
Each cell generates about 0.8-1V for at least a week with a load, or 1 month and more if not used.

Then 4 of them are put in series with a led for a week of free light ;)

Step 11: Other Designs_3: the Futuristic Lemon Battery

Similar design as the previous one.
The strange circular plastic item is a connector that you find in the box of light sticks ( 2 of them are included so you can make a sphere of light sticks)

We have 6 cells, every "cavity" contains a tiny piece of copper wire, a tiny piece of zinc wire, some lemon juice. The cavity is sealed with hot glue.

The cells are connected in series and a led is put in the center of the plastic connector. It already had a hole in the middle, perfect size for a led... here is how this battery started ;)

Step 12: Other Designs_4: the RCA Lemon Battery

Similar to the straw battery, but here instead of the copper we use the gold plated connectors from an unused gold-plated RCA plug.

With 5 of them in series we have a quite powerful battery, enough to lit a led for 2 months or powering a watch for 1 month.

Step 13: Other Designs_5: the Almost AA Battery

Here is my first attempt at making an AA battery, using only copper and zinc-plated iron wire.
Even if it does not meet the specifications of an AA battey, it was quite good anyway, even able to power a tiny pager motor.

Step 14: Other Designs_6: the (better) Almost AA LB

A better design, still not powerful as an alcaline AA battery, but much better than the previous design.

It consists in 2 cells put in series, now the voltage is about 1,5 volt that is correct for an AA battery.
The current is less than a real AA battery, I should put 3 pairs of cells in parallel for a "real" AA battery.

Step 15: Other Designs_7: the Palugraph Lemon Battery

The Paper Aluminium Graphite battery

One of the simplest battery that you can make with common household items in less than a minute. Extremely light and thin, but will last just a few hours and is not very powerful. Good for demonstrations with a voltmeter.


peak voltage: 0.6V
duration: 1-3 hours
weight: 0,42g
volt / weight ratio: 1,4 V/g
thickness: 0,15mm

Paper sheet about 3cm x 3 cm
Soft Pencil (6B - 8B)
Gel hand dish washing liquid, or lemon juice.

Draw a square with the pencil on the piece of paper, filling the same square more times until
the resistance measured with the tester between two points on the square, not less than 1 cm from each other is less than 500ohm.
Ok, you can draw whatever you want, not just a square ;)
Put the aluminium foil under it and place two small pieces of scotch on the sides to
minimize the gap from the paper and the aluminium foil and to secure them.
Finally, drop some drops of dish soap on the square drawn with the pencil.
Voila', the battery is finished!

The difference of potential between the square and the aluminium is about 0,60V and will last for about 1-3 hours, mostly because the dish soap (or lemon) will dry out.o

Step 16: Other Designs_8: the CPA Lemon Battery

A quite simpe design: a stack of copper foil - paper - aluminium foil, with a drop of hand
dish washing liquid.

Step 17: Other Designs_9: the Ultra-thin Lemon Battery

A nice design for an ultra-thin battery.

Very easy to make, just cut a rectangle 2x1cm of aluminium foil, cover it with paper tissued, wrapped on the edges; wrap around the paper a smaller rectangle cut from some copper foil.

Try making an armlet connecting 5-6 of them and a led in series ;)

Step 18: Final Considerations

Here you have seen many different designs for making a battery out of ordinary materials.

Some designs are at the moment explained better than others, I will update them soon.

All of them are made by me, I have done many searches but it seems that the classic zinc-and-copper-and-some-lemons is the only design to show and explain how Volta's batteries can be done.

And if you liked this instructable, please vote it and spread the word ;)

It is my entry for the Epilog Zing Laser Contest and I can only dream how a laser cutter could improve my research ;)
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