An apparatus for providing an optimized amount of refrigerant to a refrigeration system includes three valves coupled with a fluid coupling, the first valve being coupled between the fluid coupling and an inlet of a refrigerant source, the second valve being coupled between the fluid coupling and an outlet of the refrigerant source, the third valve being coupled between the fluid coupling and the refrigeration system, the fluid coupling having a refrigerant chamber operable to store a volume of refrigerant to selectively provide the volume of refrigerant to the refrigeration system upon operation of the first, second, and third valves.