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 ;)
If you will like this instructable, please vote it for the Epilog Contest!
The winner gets a laser cutter. It would be perfect if I would have something like that at home, I could have made my homemade folding camera way better; and would be of incommensurable help witth my next project, which i'll anticipate you that will involve giving a hand to a friend... literally.
Replacing his ugly prosthesis (and immovable, so useless too) with something more smart, using some gearmotors and nitinol wires, that I have still to test; and for the exterior, i'll use and old tecnique that was used long time ago by some fake mediums to produce moulds, supposedly modelled around materialized 'spirit hands', that were (even if obvioulsy fake) very detailed indeed...
Ok, i'm already telling you too much ;)
Step 1: The Flower Lemon battery
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 ;)