Nickel-Cadmium (NiCd) solar batteries are rechargeable batteries that use nickel oxide hydroxide and metallic cadmium as electrodes. Known for their ruggedness, long cycle life, and ability to operate in extreme temperatures, NiCd batteries have been widely used in industrial, remote, and off-grid solar applications.
They can withstand deep discharges and overcharging without significant damage, making them highly durable compared to lead-acid batteries. However, they are more expensive, have a lower energy density, and contain toxic cadmium, which requires special handling and disposal.