ELI5: How do batteries work?

Imagine a battery like a tiny playground with two slides: a positive slide and a negative slide. Kids (we'll call them electrons) really want to go down the positive slide, but they're all crowded on the negative slide.

There's a gate between the slides. When the battery is just sitting there, the gate is closed.

Now, let's say you have a toy car. You connect a wire from the negative side of the battery to the car, and then another wire from the car to the positive side of the battery. This is like opening the gate!

Suddenly, the electrons on the negative slide have a way to get to the positive slide through the wire and the car.

• The electrons rush out of the negative side of the battery.
• They flow through the wire and into the car.
• The electrons power the car’s motor, making it move.
• Finally, they go through the wire and into the positive side of the battery.

Eventually, all the electrons will be on the positive side, and the slides will be empty. When that happens, the battery is "dead" because there are no more electrons to flow and the gate is closed again. It's like all the kids have already gone down the slide! We need a new playground (battery) to play again.