Have you ever wondered how your average battery worked and why the commercials make no sense? Well here is why. It is because in a battery there is a very dense amount of electrons and and protons in a battery. And the electrons are attracted to protons. So the electrons want to go to the protons but there is a wall blocking that. They take another route and often go through a copper wire to the other side where the protons are. Along the way there is usually a light bulb ( or anything else) in the middle and the electrons have to go through it. Some metals are harder to go through than others so in a light bulb the metal they use makes it really hard for the electrons to go through. the friction of the electrons going through causes immense light to come out of that wire and then they go to the other side of the battery. It depends on the type of battery too. Your average AA battery has 1.5 volts in it that are released the bigger the battery the The more voltage sometimes but usually it just means that they last longer. That is the basic circuit for a battery. There a bunch of other things like Video game controllers, TV remotes and RC cars but those are a lot more complicated. Well now you know how a basic circuit works.