Batteries--making a voltaic pile and dissecting a battery

Dissecting a battery is one of those things I've always kind of wanted to do but didn't know I was allowed to! :) I got the idea from this site, which gives step-by-step instructions. Make sure you use only the carbon-zinc batteries, as alkaline batteries may have dangerous acids in them that can burn you!

We talked about cells vs batteries. The batteries we dissected here are technically cells—you'd need two or more to make an actual battery. A 9V battery, on the other hand, actually is a battery—you can see a picture of the cells inside it, here.

Here is our battery, all taken apart. You can see the blue plastic casing, the two round electrodes (the ends of the battery), the carbon rod (covered with black stuff which is manganese-oxide, the electrolyte), and the zinc casing (the thin metal tube that goes around it all).

We also made a Voltaic Pile, or a homemade battery with dimes and pennies. You sandwich them with paper towel pieces soaked in lemon juice and salt, and that's enough to generate a small current. We got our instructions from a book, but here are some similar instructions online. It's a pretty simple activity.

Here you see that no current is going through (our circuit isn't complete)

Here is the current generated by our tiny battery 

And here is the measurement when the current is going through Sebby's body instead of the wire---the resistance has increased (Sebby isn't as good of a conductor as a wire is) so there is less electricity getting through.

More battery activities:

There are a million descriptions online of how to make a lemon battery; here's one.

This is a similar project to ours for a homemade battery, but it involves sanding down pennies which seemed more complicated.

This is a cool site; it has diagrams of what's inside various types of batteries (in case you are curious about the ones you can't dissect yourself!) :)

Video about how batteries work