Once the processing chips got smaller, so did the devices. Smaller devices meant portability and portable products required power – specifically, battery power.

The concept of a cell that retains and supplies power dates back to the 18th century to both Benjamin Franklin and Alessandro Volta. The first lead acid battery was produced in France in 1859. In 1866, Georges Leclanché invented the electrolyte battery – a so-called wet cell. It wasn't until 1887 that a German scientist, Dr. Carl Gassner, patented the first "dry" cell, which used zinc as its primary ingredient. Gassner's battery was much like the carbon-zinc, general-purpose batteries on the market today. In 1896, the National Carbide Company, later Union Carbide and then Eveready, produced the first consumer dry cell battery. Two years later, the company made the first D cell. In 1912, the American Electrochemical Society standardized the basic consumer battery sizes, accepted in 1919 by the National Bureau of Standards, which became ANSI (American National Standards Institute).

But for most of the early 20th century, consumer batteries were made from carbon-zinc and didn't last very long. Shortly before World War II, Samuel Ruben invented the mercury primary cell. When combined with the transistor in the late 1950s, mercury batteries were used in hearing aids and transistor radios. Also during the 1950s, high-powered alkaline manganese batteries were built into camera flashes.

But it wasn't until 1959 that the modern alkaline battery was invented. In the cafeteria of the Cleveland-based Eveready battery factory, then still owned by Union Carbide, researcher Lew Urry lined up two toy cars, one containing a standard carbon-zinc battery and the second containing a prototype of an alkaline cell. To the delight of his co-workers, the car powered by the carbon-zinc battery stopped after a few feet. The car with the alkaline battery traveled back and forth across the cafeteria floor so many times, that Urry's cheering co-workers finally became bored and wandered off.

Alkaline batteries, first developed by Thomas Edison in 1914, lasted five to eight times as long as carbon-zinc batteries, still common for most consumer applications. It was well-known within the industry that alkaline was more powerful than carbon-zinc cells, but it wasn't until Urry's developments and his toy car demonstration that alkaline cells went into full commercial production.

Urry, who holds 56 patents, also helped develop rechargeable and mercury-free cells as well as lithium technology. In the late 1980s, the federal government mandated that mercury be removed from alkaline cells for environmental reasons. Alkaline batteries now produce 40 times more power than Urry's original.
Replacing battery after battery, however, in a portable-centric gadget world, became both inconvenient and expensive. Efforts to develop a reusable rechargeable power cell were always on developers' minds and picked up steam in the early 1980s. German scientist Johann Wilhelm Ritter made the first attempt at a rechargeable power cell in 1802. Nearly a century later in 1899, Waldmar Jungner invented the nickel cadmium rechargeable battery. But Junger's invention was expensive, and therefore useless as a consumer technology. The technology was refined throughout the 1930s and 1940s. In the late 1950s, hearing aid company Sonotone developed a rechargeable flashlight battery that replaced two D cells.

But it wasn't until the mid-1980s that rechargeable nickel-cadmium batteries were made for consumer use. Longer-lasting nickel metal hydride (NiMH) batteries were introduced in the late-1980s.

Development on rechargeable batteries using lithium, the lightest of all metals, began in 1912. But rechargeable lithium cells weren't ready for commercial use until Sony introduced the first practical lithium-ion (Li-ion) battery in 1990 for use in the company's camcorders. Around this time, more durable single-use lithium batteries also hit the market, first in camera sizes, then in the familiar AA size for use in high drain products such as digital cameras.

Lithium-ion batteries now power most portable products including camcorders, digital cameras, PDAs and cell phones. The newest power technology is the even lighter, thinner and more pliable lithium polymer. New formulations continue to be developed, including hydrogen cells to provide more power for increasingly higher-drain digital products.