Dc-dc converters, solar charging system and the movable body

The present invention relates to DC-DC converters, solar charging system and the movable body. The DC / DC converter comprising a first DC / DC converter and the second DC / DC converter for performing DC voltage supplied from the first DC / DC converter / DC conversion. The first DC / DC converter or the second DC / DC converter is one of fixed-factor DC / DC converter, and the other of the first DC / DC converter or the second DC / DC converter is a variable factor DC / DC converter.