how+batteries+work

Batteries are all over the place in cars, laptops mp3 players and cell phones. A battery is really a can full of toxic chemicals that produce electrons. Chemical reactions that produce electrons are called electrochemicals raections.

if you look at any battery, youll notice that has two terminals. one terminal is marked (+), or positive, while the other is marked (-) or negative. In an AA,C or D cell ( normal flashlight batteries) the end of the battery are the terminals. In a large car battery ther are two heavy lead posts that act as the terminals.


 * Electrons** collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can (and wear out the battery very quickly -- this also tends to be dangerous, especially with large batteries, so it is not something you want to be doing). Normally, you connect some type of **load** to the battery using the wire. The load might be something like a lighst bulb, electronic circuit like a radio.

­Inside the battery itself, a chemical reaction produces the electrons. The speed of electron production by this chemical reaction (the battery's **internal resistance**) controls how many electrons can flow between the terminals. Electrons flow from the battery into a wire, and must travel from the negative to the positive terminal for the chemical reaction to take place. That is why a battery can sit on a shelf for a year and still have plenty of power -- unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place. Once you connect a wire, the reaction starts. The ability to harness this sort of reaction started with the voltaic pile.