Battery

Today, batteries are useful if you can’t plug a device into an outlet, but when they were first invented, they were the only things capable of generating an electric current. Th e i nvent i on that ELECTRIFIED the planet

Electrical storm

Electricity is as old as lightning. In 1752, American scientist benjamin franklin flew a kite with a metal key in a storm and realized that the sparks coming from the metal proved that lightning is a form of electricity. This static (“at rest”) electricity was first discovered in ancient Greece by a mathematician named Thales who produced a static electric charge by polishing amber with animal fur.

Frog findings

Even though people knew about electricity, they did not yet know how to produce an electric current—a flow of electric charge. In 1780, Italian doctor luigi galvani noticed that the muscles in the legs of dead frogs twitched when they made contact with two different metals. He thought this was caused by “animal electricity” in the frog itself. But fellow scientist alessandro volTa realized that the electricity wasn’t due to the dead frog, but to the different metals.

Understanding electric current led to the electricity supply we have It paved the way for... come to rely on today. The first public electricity lit the streets of Godalming, England, in 1881. In Galvani’s experiment, the frog was the equivalent of the brine-soaked paper in Volta’s pile.

Did you know? French emperor Napoleon I was so impressed with Alessandro Volta’s invention of the voltaic pile that he made him a count.

Volta had discovered that two different metals submerged in acid could generate a tiny electric current between them. In 1800, he created his voltaic pile—the world’s first battery. It was made from layers of copper, cardboard soaked in saltwater, and zinc— each group of three makes a “cell,” and the more cells, the greater the electric current produced. The current is generated by a chemical reaction that moves electrons from one metal to the other.

Zinc disk

Saltwatersoaked cardboard Copper disk By the way... It took me years of experimentation before I discovered the first practical method of generating electricity. The unit “volt” is named after me.

Charging ahead

The voltaic pile was groundbreaking, but it leaked and didn’t last long. The first rechargeable battery was the lead-acid battery invented in 1859 by French physicist Gaston Planté. The basic principle of this version remained unchanged into the 21st century. The first dry battery (using paste instead of liquid) was the zinc-carbon one created by German scientist carl gassner in 1886, which led to the convenient batteries we put into flashlights today.

How it changed the world

Volta also discovered methane gas while poking around in a marsh, and invented an exploding pistol that he used to figure out the oxygen content of air. The battery was the first means of generating an electric current and the first easily portable energy source. Without it, there would be no phones, radio, or batteryoperated devices.

The electric flashlight first came into use in 1899. Like today’s flashlights, it used a dry-cell battery. Tablet computers, cell phones, and other mobile devices in everyday use all depend on a battery as a power source.