NOVELTY - A liquid supply reservoir comprises first flexible pouch having high vapor pressure substance; second flexible pouch enclosing a liquid; and liquid conduit to provide liquid communication between the second pouch and an evaporator. The high vapor pressure substance causes the first pouch to exert pressure on the second pouch, thus assisting the flow of liquid from second pouch to liquid conduit.    USE - For supplying liquid to sorption cooling device used in temperature-controlled shipping container (claimed) required to maintain a temperature below ambient for a time (e.g. 1-120 hours) to complete the delivery of the container and its content (temperature-sensitive products).    ADVANTAGE - The invention enables the internal cavity of a container to be maintained at a reduced temperature for extended period of time.    DETAILED DESCRIPTION - A liquid supply reservoir for sorption cooling device comprises a rigid housing (614); a first flexible pouch (602) disposed within the housing and enclosing a high vapor pressure substance (606); a second flexible pouch (604) disposed within the housing adjacent to the first pouch and enclosing a liquid (608); a liquid conduit (612) for providing liquid communication between the second pouch and an evaporator. The high vapor pressure substance causes the first pouch to exert pressure on the second pouch, thus assisting the flow of liquid from the second pouch to the liquid conduit.    INDEPENDENT CLAIMS are also included for:    (1) a sorption cooling device comprising an evaporator for providing cooling; an absorber for absorbing vapor for the evaporator; a vapor passageway for directing vapor from the evaporator to the absorber; and a liquid supply reservoir;    (2) a temperature-controlled shipping container incorporating a sorption cooling device; and    (3) a method for operating a sorption cooling device comprising providing a first portion of liquid to the evaporator at a first liquid supply rate and providing a second portion of liquid to the evaporator at a second liquid supply rate that is lower than the first rate.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a liquid reservoir system for sorption cooling device.    First flexible pouch (602)    Second flexible pouch (604)    High vapor pressure substance (606)    Liquid (608)    Liquid conduit (612)    Rigid housing (614)