Abstract: An improved electrical system for a recreational vehicle or the like including a first battery for starting the engine and the like, having a second or auxiliary battery for providing electric current to interior lights and the like. The improvement includes a link circuit for electrically linking the first and second batteries and a supplemental electric current source such as an independently powered generator or an electric utility current source, and control structure for allowing electric current to flow through the link circuit from the second battery and/or the supplemental electric current source to the first battery and the first battery load without allowing the flow of significant electric current from the first battery to the second battery or the second battery load.

Abstract: A core element, as for example a pipe, tube, hose or the like, has thermal insulation applied thereto in the form of a plurality of layers of tape applied in a continuous process in which conditions are selected to deliberately create wrinkles thereby defining air spaces serving to further reduce the transmission of heat through the composite thermal insulation. The wrinkles may be introduced by wrapping the tape about the pipe at an applied angle greater or smaller than the angle required for a given effective diameter, overlap factor, and width of tape, At the outer surface of the wrap the tape is substantially wrinkle-free and a jacket of polyvinyl chloride or the like is applied thereto.