What is A Battery?

A battery is a device that converts chemical energy into electrical energy. Batteries have two electrodes, an anode (the positive end) and a cathode (the negative end). In between the battery’s two electrodes runs an electrical current caused primarily from a voltage differential between the anode and cathode. The voltage runs through a chemical called an electrolyte (which can be either liquid or solid). This battery consisting of two electrodes is called a voltaic cell.

The first inclination that an electrical path-way from an anode to a cathode within a battery or in this first instance “a frog” occurred in 1786, when Count Luigi Galvani (an Italian anatomist, 1737-1798) found that when the muscles of a dead frog were touched by two pieces of different metals, the muscle tissue twitched.

This led to idea by Count Alessandro Giuseppe Antonio Anastasio Volta (Feb. 18, 1745- March 5, 1827), an Italian physicist who realized that the twitching was caused by an electrical current that was created by chemicals. Volta’s discovery led to the invention of the chemical battery (also called the voltaic pile) in 1800. His first voltaic piles were made from zinc and silver plates (separated by a cloth) put in a salt water bath. Volta improved the pile, using zinc and copper in a weak sulfuric acid bath and thus invented the first generator of continuous electrical current.

In 1820, the French physicist André-Marie Ampère discovered many of the laws governing the relationship between electricity and magnetism, along with how a battery works. Ampere found that electrical current move through conductors, and that electrical charges flow from one electrode to the other. Ampere invented the astatic needle, which detected electrical currents.

In an interesting side bar regarding Ampère and Volta:

From Volta’s work we get the Volt – or V – which is an electrical measure of energy potential. For example you can think of energy potential as the pressure being exerted by all the electrons of a PDA Battery’s negative terminal as they try to move to the positive terminal.

From Ampère’s work we get Amps – or A – which is measures the volume of electrons passing through a wire in a one second. One Amp equals 6.25 x 1018 electrons per second.

From both Volts and Amps we get the formula for a battery’s full potential measured in Watts: Volts x Amps = Watts. Watts are important because a watt represents the electrical energy spent by a battery (power generator) and used by an electrical device. Watts in effect is the measure of the amount of work done by certain amperage (amount) of electric current at a certain pressure or voltage.

The batteries we use today are simply variations of the early battery or voltaic pile. Today’s battery’s are made up of plates of reactive chemicals separated by barriers, being polarized so all the electrons gather on one side. The side that all the electrons gather on becomes negatively charged, and the other side becomes positively charged. Connecting a device creates a current and the electrons flow through the device to the positive side. At the same time, an electrochemical reaction takes place inside the batteries to replenish the electrons.

The effect is a chemical process that creates electrical energy with one downside: about 80 percent of the energy put into batteries is lost through this process.

Though the battery maybe inefficient we still need the battery, especially battery replacements that are inexpensive. We are power hungry consumers. We like our power and lot’s of it. Lithium-ion batteries (Li-ions) are generally considered the most powerful, offering the same energy as nickel metal hydride (NiMH) batteries, with 20 to 30 percent less weight. They are expensive compared to older battery technologies, but are valued for high-power portable applications, such as laptops, cell phones, and PDAs.

Until next time – Dan Hagopian, BatteryShip.com