Batteries are the most common energy carrier component of electric aircraft, due to their relatively high capacity. Batteries were the earliest source of electricity, first powering airships in the nineteenth century. These early batteries were very heavy and it was not until the arrival of technologies such as nickel-cadmium (NiCd) rechargeable types in the second half of the twentieth century, that batteries became a practical power source for aircraft. Modern battery types include lithium-based and a number of other less widely used technologies. Such batteries remain a popular power source today, although they still have limited endurance between charges and hence limited range.