![Ni-Cd Battery](https://www.eurotronix.com/images/categories/1551092518-baterias-NiCd.jpg)
The so-called Nickel-cadmium batteries belong to the group of secondary or rechargeable batteries. They use a nickel hydroxide cathode and an anode of a cadmium compound. The electrolyte is potassium hydroxide and its power density is 50 Wh/kg. These types of batteries allow overcharging and a wide range of working and storage temperatures.