什麼是電池

將化學能轉換成電能的一類器件，由一組電子元件組成。溼電池（如汽車電池）中有自由流動的液態電解質；乾電池（如手電筒電池）內的電解質被控制在吸收性材料中。配置好的化學物質，電池的負電極就能釋放電子，流過（參閱electric current）電池的外電路（在以電池為電源的裝置中）而到達正電極。電壓取決於所用的化學物質以及串聯的電池數；電流取決於總電路的電阻（包括電池的電阻，取決於電極的大小）。多個電池可以串聯（一個電池的正極連到下一個電池的負極），以增加總電壓；或者也可以並聯（正極連正極，負極連負極），以增加總電流。手電筒用的標準乾電池以及在海上、礦井、公路和軍事上用的某些溼電池是不能再充電的；汽車電池和無線裝置中用的乾電池，以及某些軍用和飛行器用的電池是可以反覆充電的。

battery

Any of a class of devices, consisting of a group of electric cells, that convert chemical energy into electrical energy. A wet cell (e.g., a car battery) contains free liquid electrolyte; in a dry cell (e.g., a flashlight battery), the electrolyte is held in an absorbent material. Chemicals are arranged so that electrons released from the battery's negative electrode flow (see electric current) through a circuit outside the battery (in the device powered by it) to the positive electrode. The voltage depends on the chemicals used and the number of cells (in series); the current depends on the resistance in the total circuit (including the battery—and thus on electrode size). Multiple batteries may be connected in series (the positive electrode of one to the negative electrode of the next), increasing total voltage, or in parallel (positive to positive and negative to negative), increasing total current. Standard dry cells used in flashlights and certain wet cells for marine, mine, highway, and military use are not rechargeable; car batteries, many dry cells used in cordless appliances, and batteries for certain military and aerospace uses may be recharged repeatedly.