Secondary cells, also known as rechargeable batteries, are gaining popularity due to their ability to be reused several times. There are various synonyms that can be used for the term secondary cells, including rechargeable batteries, storage batteries, and accumulators. These batteries are differentiated from primary cells, which cannot be recharged once their power is depleted. Secondary cells come in various chemistries, such as nickel-cadmium, lead-acid, and lithium-ion. They find extensive application in devices like smartphones, cameras, and electric vehicles. Overall, the development of secondary cells has revolutionized the energy storage industry and opened up new possibilities for sustainable energy solutions.