Battery

This article is about electrical batteries. For the crime of battery, see battery (tort).

A battery is a device that can store electricity. Some are rechargeable, and some are not. They store direct current (DC) electricity.

A battery really means two or more wet or dry cells connected in series for more voltage, or in parallel for more current, although people often call a cell a battery. AA, AAA, C, and D batteries all have 1.5 volts. The voltage of a cell depends on the chemicals used while the amount of power or current it can supply also depends on how large the cell is; a bigger cell of a given type can supply more amps, or for a longer time.

The chemical reactions that occur in a battery are exothermic reactions and, thus, produce heat. For example, if you leave your laptop on for a long time, and then touch the battery, it will be warm or hot. The batteries used in laptops are called lithium-ion batteries.

Batteries come in lots of different shapes and sizes and voltages. It is possible, but not easy, to run wires to use an odd size battery for an odd purpose.

Batteries are always more costly/expensive than mains electricity. But mains electricity is not suitable for things that are mobile.

Bicycles have tail-lights that can be operated by batteries, and sometimes by a little generator powered by the wheels.

Hand and foot generators can be used to replace batteries in various devices, but they can be tiresome.

Wind-up generators are now available to power small clockwork radios, clockwork torches, etc.

Since clockwork clocks have been around for hundreds of years, and batteries for two hundred, it is amazing that no-one thought of a clockwork torch until recently.

Rechargeable batteries are recharged by reversing the chemical reaction that occurs within the battery. But a rechargeable battery can only be recharged a given amount of time (recharge life). Even iPods, with built in batteries, cannot be recharged forever. Moreover, each time a battery is recharged, its ability to hold a charge is degraded a bit. Non-rechargeable batteries should not be charged as various caustic and corrosive substances can leak out, such as potassium hydroxide.

History

The very first batteries were invented in the Middle East around 1000 B.C. Then they were buried and forgotten about.

The first battery was invented in 1800 by Alessandro Volta. Nowadays, his battery is called the voltaic pile.

Later batteries were bottles with a fluid and some metal rods in them. People had to be careful not to turn these batteries upside-down so the fluid would spill.

In modern batteries, the fluid is "soaked up" in a kind of paste. And everything is put in a completely tight case. Because of this case, nothing can spill out of the battery. An exception is car batteries; they still have liquid inside.

Types of batteries

• Alkaline battery, "alkaline", not rechargeable
• Leclanche battery, "super heavy duty", not rechargeable
• Nickel metal-hydride battery, "NiMH", rechargeable
• Nickel cadmium battery, "NiCd", rechargeable
• Lead acid battery, rechargeable, car battery
• Lithium battery, unrechargeable, "coin cell"
• Lithium-ion battery, rechargeable, used in cell phones and laptops
• Mercury battery, unrechargeable
• Silver oxide battery, unrechargeable, watch battery

Alternatives to batteries

• Solar cell

Other pages

• Dry cell
• Rechargeable battery
• Table of batteries