A battery is a power source consisting of one or more electrochemical cells with external connections. They are used for powering electrical devices such as flashlights, mobile phones, and electric cars. Italian physicist
Alessandro Volta is generally credited with discovering the first practical
battery. He invented his battery in 1800, it consisted of discs of two different metals, such as copper and zinc, separated by cardboard soaked in brine (high-concentration solution of salt
NaCl in water
H2O). However in the present we have portable rechargeable batteries with many advanced features.