Introduction
An electric battery is defined as a device that makes use of either one or an assembly of electrochemical cells that convert the stored chemical energy within them into electrical energy. Each cell has a positive terminal, cathode, and a negative terminal, anode. An estimate carried out in 2005 concluded that worldwide battery industry roughly generates $48 billion in annual sales with a 6% annual growth. Benjamin Franklin used the word battery in 1748 to describe his multiple Leyden jars. Alessandro Volta described the first electrochemical battery known as voltaic pile in 1800.
How Does a Battery Work? 
Batteries work by converting chemical energy into electrical energy. A battery is composed of electrochemical/voltaic cells that contain electrolyte (conducting material) and electrodes. The process of electron flow occurs when the electrons are deposited at the cathode and when electrons are removed from the anode during charging. The electrodes do not come in contact and the flow of electrons takes place via the external circuit (hence the current flows) while the cations and anions flow in electrolyte.
Types of Batteries 
Primary Batteries
The process of converting chemical energy into electrical energy is irreversible and once the reactants finish, the battery is exhausted.
- Zinc-Carbon Batteries
- Alkaline Batteries
Secondary Batteries
These are the batteries that can be charges; that is to say that the conversion process is reversible by supplying electric current to the battery.
- Lead Acid
- Nickel Cadmium
- Nickel Zinc
- Nickel Metal Hydride
- Lithium Ion
Applications of Batteries
- Cars
- Toys
- UPS
- Smartphones
- Gadgets
- Laptops
Precautionary Measures 
- Never charge a primary battery.
- Batteries should never be swallowed.
- Beware of the fact that batteries can leak.
- Leaked materials are harmful.
- Do not over charge a battery.
- Make sure your battery charges completely.
- Don’t keep batteries connected to power source once they’ve been charged.
- Don’t dispose off the battery in fire.