Today, thanks to modern technology,
nearly everything we use is battery powered. A battery is
simply a container full of chemicals that produce electrons
and thus power. Some of the prime attributes of a battery
are size, ability to provide high energy density, and
durability. Battery manufacturers are well aware of consumer
demands and have responded by producing batteries that are
best suited for specific applications. For example, the
mobile phone industry has emphasized small size, while
placing less importance on longevity.