電池可以說是我們生活中司空見慣的東西。可是您知道電池是怎么“發電”的么？如果您還記得小學里學過的“電流”這一課，那就來復習一下英文版的電池原理吧！

A battery, by definition, consists of a group of two or more primary or secondary battery cells, which convert chemical energy into electrical energy. A portion of the chemical energy a cell produces is transformed into heat, and a portion into an electric current.

Primary battery cells can only be renewed during down time, when they replenish their chemicals. When one reach for his or her emergency flashlight, which contains a type of primary cell named an ordinary cell, and it fails to light up, one falls victim of this very principle.

Each and every primary cell uses various chemicals, and contains electrodes and an electrolyte, a liquid. Electrodes, a.k.a. "cell elements," consist of either two different metals, or one metal and carbon. Element number one, the cathode, is primarily zinc. Element number two, the anode, is primarily carbon.

A chemical action sets the electrons free, when it triggers the cathode slowly to dissolve into the liquid electrolyte. A circuit provides the escape route for the newly paroled electrons, and they rush down the hatch in the form of an electric current. Unfortunately, their freedom is short-lived, because, once an electrical conductor is connected to the two elements; the current flowing through it is recaptured as electricity.

Secondary battery cells merit less discussion, as they automatically recharge, when an electric current is injected through them. Primary examples of a secondary battery cells are the storage cells used to start, or not to start, our car batteries. Because a storage battery does not actually store electricity, it instills in one a false sense of security. One is well advised to carry jumper cables in our cars, for those times when, much to ones chagrin, the battery fails to start.

The misnomered "storage battery," draws its power from chemical charges. Inside a storage battery, one finds a set of plates made of metallic lead, and a set made of lead peroxide. When both sets of plates are immersed in sulphuric acid, they undergo a chemical change, which transforms them into lead sulphate, which in turn produces the electrical current in the storage battery, which does not store.

electrodes: 電極

electrolyte: 電解液

cathode: 負極

anode: 正極

chagrin: 懊惱

immerse: 沉浸，使陷入

sulphate: 硫酸鹽

（英語點津 Annabel 編輯）