A rechargeable battery is a type of battery that can be recharged and reused multiple times. The most common type of rechargeable battery is the nickel-cadmium (NiCad) battery, which is composed of nickel and cadmium. NiCad batteries are known for their long life and high energy density, making them ideal for use in portable electronics such as laptops, cell phones, and digital cameras. They are also used in electric vehicles and other applications where frequent recharging is necessary.