Potato Battery Experiment - Why is mine not working???

So, the topic this term is still "Foodnimals" and Mikail was given an experiment last two weeks as homework. It was the potato battery experiment..The instructions didn't come with pictures so the parents were pretty much guessing how to do it and most of us turned to Google of course. 

I am not going to explain the science behind the potato battery here as I'm sure you can find that all over the internet. The basic thing that you need to know is that - the two main elements that are producing the energy are the copper (positive electrode ) and the zinc (negative electrode) the acids in potato just causes the reaction between the two to produce power. With that in mind.. your battery is not going to work if you don't have the two elements together. 

Things that you will need are:

For those who are clueless (like me) what kind of nails should you buy and what are alligator clips:

I bought the nails above and alligator clips from ACE hardware. The alligator clips are like this:

The experiment pretty much works on all citrus fruits I think cos we tried oranges and lemons but using potatoes produces more power. I read somewhere that cooked potatoes works even better but nah we were too lazy to cook them. 

All you need to do is:

1) stick 1 nail and 1 coin on each fruit / potato (not too near)

2) connect the nail from 1 fruit to the coin in the other with the alligator clip (please buy one with the wire attached and not just the head)

3) then take the second alligator clip and connect the nail to the - side of the battery slot of the timer.

4) lastly take the third alligator clip and connect the coin to the + side of the battery slot.

Like this (tadaaa!)

LED timer on lemon battery and potato battery (pic is of 4 potatoes because I was trying to power up an LED light bulb earlier and I was too lazy to take away two potatoes)

Remember to buy a timer that runs on 1 AAA battery. I bought my first one (the white one from Daiso but it runs on the small LR44 battery which was why I couldn't use the alligator clip cos the + and - slots are tricky to find. So I had to use copper wires instead to try and find the + and - points. The second LED clock (red color) I found at Mr DIY and costed me RM8.60 (if I am not mistaken)

Now, you will read somewhere also that you can do this with a LED bulb and you might go like me and say.. hmm.. LED bulb is waaay easier  to find in hardware stores than a LED timer or clock.. yes easier to find BUT if you want to use a bulb instead, you need to buy exposed ones like these:

LED bulbs for potato battery experiment (found in ACE Hardware store)

So, some parents like me tried the LED bulbs and then hmm.. theirs didn't work.. the bulb just won't light up.. why??? that's because the LED bulbs uses more power than the LED timer or clock.. so using two oranges or two lemons won't work.. heck even 4 potatoes connected with alligator clips didn't work with those bulbs up there.. I had to use 4 potatoes connected with copper wires.. then the bulb lighted up.. and mind you I was only trying to power up one LED bulb.. 

So.. if you are feeling adventurous and wants to do the light bulb.. you might need these as well:

Pliers to cut the wire, copper wire and electrical tape to connect the wire to the bulb)

So, you just cut the copper wire using the pliers to desired length and wrap the wire one end around the coin and the other end around the nail. (repeat till all nails and coins are connected to each other) and then connect the last coin to one end of the bulb and connect the last nail to the other end of the light bulb (hard to tell which is which so if it does not work, change the side of the bulb that you connect the coin/ nail to) like this:

This is the LED light bulb bought from ACE.. it requires 4 potatoes connected with copper wires to light up. 

I tried to light up the LED bulb from ACE once by using two oranges and again by using 4 potatoes but it didn't work.. then I went to find a smaller light bulb (lower voltage) and the 4 potatoes worked but the light bulb is not very bright as picture before. 

All this got me curious.. so I went to the hardware store again and bought a multimeter haha and tried various things:

So.. as we can see.. two oranges produces the least power.. 2 lemons are much better and the 2 potatoes win by a slight margin..

4 potatoes connected using alligator clips produces lesser power than 4 potatoes connected using copper wires.

And then we tried a different approach.. will moving the nail and coin closer to each other produce a higher voltage or lower? apparently moving them closer (nails and copper coins not the oranges yeah) produces higher voltage... then I thought since the source of electrons are the copper and zinc elements.. what if I put in two coins and two nails in 1 orange? what will happen then? and you can see from the picture on the far right above.. the voltage went down :p 

Waahhh.. ok.. the geek in me is now satisfied haha.. the mommy gets more excited than the son 😬

Hope your experiment works!