National Battery Day is observed on February 18, 2017. Think on that day about the usefulness of the batteries - and charging some up again, if you like. Recognize, just how important the simple battery is to our way of life. In electricity, a battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Batteries have become a common power source for many household and industrial applications.
There are two types of batteries: primary batteries (disposable batteries), which are designed to be used once and discarded, and secondary batteries (rechargeable batteries), which are designed to be recharged and used multiple times. Batteries come in many sizes, from miniature cells used to power hearing aids and wristwatches to battery banks the size of rooms that provide standby power for telephone exchanges and computer data centers. (With material from: Wikipedia)