Wet cells

One kind of battery is called a wet cell. A wet cell has two metal poles, or electrodes. One pole is called the negative pole (—) and the other pole is called the positive pole ( + ). The positive pole is made of lead oxide, the negative pole is made of spongy lead. Both poles are in sulfuric acid. When a wire is connected between the poles, the sulfuric acid causes little bits of electricity, called electrons, to form on the negative pole. The electrons flow from the negative pole through the wire to the positive pole.

This goes on until there are no more electrons left. lt is possible to put more electrons into the battery by connecting the wires to a direct-current (DC) generator. This is called recharging the battery. After the battery has been recharged, electricity will flow across the wires again. When electricity flows from the battery, the battery is discharging. The speed with which it discharges is hard to believe. The electrons travel through it at the amazing speed of 186,000 miles a second.

A wet cell has many uses. It is often used in emergencies when an electric generator has broken down. It is mostly used in automobiles, where three such cells are connected together. This is called a storage battery. When you wish to start the automobile the battery gives electricity to the starter and the spark plugs. When the automobile's engine is running, a generator attached to the engine sends electricity back to the battery. In this way a battery can be discharged and recharged at the same time, so that it is always ready for use. When the engine is not running, the battery supplies electricity for the lights and horn. If the automobile has a radio and cigarette lighter, the battery also supplies them with electricity.