A battery is a device that produces electrical energy from a chemical reaction. Another name for a battery is voltaic cell. Voltaic means to make electricity.
Most batteries contain two or more different chemical substances. The different chemical substances are usually separated from each other by a barrier. One side of the barrier is the positive terminal of the battery and the other side of the barrier is the negative terminal. When the positive and negative terminals of a battery are connected to a circuit, a chemical reaction takes place between the two different chemical substances that produces a flow of electrons (electricity).
When a battery is producing electricity, one of the chemical substances in the battery loses electrons. These electrons are then gained by the other chemical substance.
A battery is designed so that the electrons lost by one chemical substance are made to flow through a circuit, such as a flashlight lamp, before being gained by the other chemical substance. A battery will produce a flow of electrons until all of the chemical substances involved in the chemical reaction are completely used.
Hi Aurora. We tried ketchup and it worked for us. You can hear the crackle when you put the clip in the ketchup too.
Wow – great job figuring out something that worked!!
We tried this with lemon juice and could not hear any crackling sound. When we used tomato juice my one son said he could hear it faintly, but me and my other son when we built the “battery” we did not hear anything. So I went to the potato and a couple of nails. I stuck the two nails in different sides of the potato and connected the alligator clips to one nail and when we touched the other clip to the other nail we could definitely hear a crackling sound. 🙂
You’re listening for a cracking or clicking, and not much of it. You need a careful ear to pick it up. You can try different metals in place of the copper, like a brass screw or a shiny metal key.
Hi, we just tried it, and had nothing happened. Just wondering if we could use anything else apart from copper pennies?
Earnest
Would using rechargeable batteries make a difference? We are trying this tomorrow.
Yes, foil is listed as one of the materials needed!
hi hello can you use alumiom foil?
Got it… here’s another thing you can try instead of the tomato juice-foil-penny setup. Find 12 shiny copper pennies and zinc washers of the same size as the pennies, and also cut out 12 small circles paper towel (also the same size). Soak the paper towel circles in salted vinegar (1 tablespoon salt per cup of vinegar). Make a stack like this: one penny, one washer, one circle of soaked paper towel, one penny, one washer, one circle of soaked paper towel. Finish with a washer. Now touch one end of one wire to the top of the stack and the other to the bottom, and you’ve just made a battery!
Hi Aurora,
We could hear the crackling noise when we hooked up the headphones to the regular batteries but couldn’t hear any crackling noise when we hooked them up to the aluminum/tomato juice/copper one. I thought our penny was as shinny as could be but we will try the experiment again with a different one. We’ll let you know how it goes.
Thanks!
Alex, Philip and Annie
Hi Alex, Phillip, and Annie! I am sorry you’re having trouble with this experiment.. let me see if I can help. When you say “it didn’t work”, what exactly do you mean? What did or didn’t happen that you were expecting? Sometimes “nothing” means something, so be really clear about your observations, especially since I am not right there with you! 🙂
This experiment doesn’t give “big” results – it’s a very quiet crackling sound you’re listening for. When I’ve done this one with groups of kids, the biggest issue is that they’re using dull pennies. You need copper, not dimes, because the copper is needed to be one of the electrodes (the plating of the dime isn’t going to work in combination with the foil). You need something acidic, like tomato juice or lemon juice (no sugar) in order for this experiment to work.
Hi Aurora, we tried the batteries and it worked fine but then we tried the tomato sauce and pennies and it didn’t work. We also tried with different juices and objects and still nothing happened. We even tried to create our own experiment with dimes, vinegar and sugar on aluminum and still nothing worked. Please help.
Thanks,
Alex, Philip and Annie
this was awesome
This is Jake again. Aurora what if you used different battery ? What would happen?
Try it and tell me what happens!
Can you use ketchup instead ?
It’s not just the volts that a motor needs, it’s also current, both of which together make power. (Power = voltage x current).
If you’ve ever wondered what the difference between a AAA and a D-cell battery is… it’s current! They both have the same voltage (1.5V each), but D-cells are a lot heavier and larger than a AAA, right? That’s because it delivers a lot more current than a AAA battery.
A potato clock doesn’t have nearly enough current to make it turn, and it might have enough to power an LED, depending on your LED. Some require more current than others. Also, depending on how you connected the potatoes up (in series or in parallel), they will generate more voltage (when connected in series) or more current (when connected in parallel). There’s a write up about series and parallel circuits, as well as the difference between current and volts in Unit 10 that you might like.
This experiment morphed into making a potato battery … we made 6 potato batteries in circuit and managed to get 5.84 V on our multimeter, but it wouldn’t light a LED or run a 1.5-3 V motor. Why? We checked the light/motor with a normal battery and they worked.