How battery chargers work

If you've read our main article on batteries, you'll know all about these portable power plants. An example of what scientists refer to as electrochemistry, they use the power of chemistry to release stored electricity very gradually.

What happens inside a typical battery—like the one in a flashlight? When you click the power switch, you're giving the green light to chemical reactions inside the battery. As the current starts flowing, the cells (power-generating compartments) inside the battery begin to transform themselves in startling but entirely invisible ways. The chemicals from which their components are made begin to rearrange themselves. Inside each cell, chemical reactions take place involving the two e