Cool Kids Science Experiments - Fruit Battery

This is another one of my favorite kids science experiments. For this one, have your son or daughter begin by rolling a grapefruit or orange on a table so it can get soft. This will also move around the juices inside, but will keep it intact. Once they have done this for a few minutes, insert a two inch galvanized nail and a similar sized copper one into the fruit a couple of inches apart. Make sure you do not penetrate the other side.

Starting to sound better than the other kids science experiments you have researched, right? Ok, now get a Christmas tree light bulb that is about 2 inches long and remove a bit of the insulation from the leads. Attach a lead to each nail with electrical tape. Presto! You will see the impressive light!

What happens is the acid in citrus conducts electricity. You can also try other fruits such as lemons and limes to see if they produce more or less of a charge. This will be evident by the strength of the glow. You can also try different sizes to see how it affects the results. If you have a multimeter, use it to measure the current that is being produced.

There are a whole bunch of kids science experiments, but I know you will have a great time with this one. It also doesn’t cost a lot and will really impress your child’s classmates. As science fair projects go, this one is a winner!