NOVELTY - The device (1) has two photovoltaic panels (2) connected together by respective joints (12a, 12b). Each joint has a flexible envelope i.e. tubular strap (3), that encloses electric cables (4). The tubular strap is made of textile material i.e. synthetic fiber fabric, and has width of 35 mm. The tubular strap is fixed to each photovoltaic panel by a thermosetting resin layer. The tubular strap is coated with a coating material layer. The electric cables are connected to polar terminals by two electrically conductive adhesive bands, respectively.    USE - Foldable energy converter device for supplying power to an electronic navigation apparatus such as navigation light, radio, radar and global positioning system, and a comfort apparatus such as refrigerator and lighting device, during boating, camping and hiking.    ADVANTAGE - The converter device can be fabricated in an inexpensive manner. The two photovoltaic panels are connected together by respective joints so as to obtain efficient converter device, while assuring compact and lightweight converter device. The tubular strap is made of textile material so as to provide excellent flexibility to the joint during folding of the converter device, and to ensure better mechanical resistance to humidity, salt water, wind, dirt, dust and heat, while assuring better protection of the electric cables, thus improving the life duration of the converter device. The electric cables are connected to the polar terminals by the electrically conductive adhesive bands, respectively, thus facilitating the fabrication of the panels, and hence facilitating the fabrication of the converter device. The joints provide reliable mechanical connection between the panels. The configuration of the converter device assures mass efficiency of 18 Watt per kilogram, and surface efficiency of 100 W per square meter, and assures better photovoltaic conversion efficiency. The configuration of the converter device assures robustness of the converter device so as to utilize the converter device in hostile medium, while assuring high operating power higher than 100 W, of the converter device. The converter device can be operated in a reliable manner.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for fabricating a foldable energy converter device.    DESCRIPTION OF DRAWING(S) - The drawing shows a top perspective view of a foldable energy converter device provided with panels in unfolded position.    Foldable energy converter device (1)    Photovoltaic panels (2)    Tubular strap (3)    Electric cables (4)    Joints (12a, 12b)