A rechargeable battery is also known as a secondary battery. It stores energy and is connected to a load which refers to any system that requires electricity. Whenever the load requires electricity, the battery is discharged with the help of a chemical reaction. This reaction can be reversed to charge the battery again.
In essence, these batteries can be used multiple times, thus making them one of the most cost-effective ways of storage. A few examples of rechargeable batteries areLead-acid, Lithium-ion, Nickel-cadmium, and Nickel-metal hydride.
Rechargeable batteries like Lead-acid and Lithium-ion are used in data centers, telecom sites, and other industrial facilities for their UPS which acts as a backup power source in case of a power interruption.