NOVELTY - The container arrangement for a fuel cell system, comprises a coolant container (2) and a module having an ion exchanger material that is introduced in the coolant container by means of an insertion opening. The module has a protective sleeve, which brings to seal the insertion opening against an environment of the coolant container when the module is introduced in the coolant container. The protective sleeve comprises a sealing element, which is supported on the nozzle (3) of the coolant container having opening.    USE - Container arrangement useful for a fuel cell system.    ADVANTAGE - The container arrangement can be efficiently and economically produced.    DETAILED DESCRIPTION - The container arrangement for a fuel cell system, comprises a coolant container (2) and a module having an ion exchanger material that is introduced in the coolant container by means of an insertion opening. The module has a protective sleeve, which brings to seal the insertion opening against an environment of the coolant container when the module is introduced in the coolant container. The protective sleeve comprises a sealing element, which is supported on the nozzle (3) of the coolant container having opening and/or which is screwed on the protective sleeve in an interior circumference side or external circumference side. A stroke for limiting insertion of the module in the coolant container is provided on the module and/or the coolant container. A guide track (12) is provided for positionally correcting the insertion of the module in the coolant container. The module introduced under formation of a sealing seat in the coolant container is snapped with the coolant container. The module has handling elements and/or a reception area in a connecting position for the handling elements, by which the module is detached from the coolant container. An INDEPENDENT CLAIM is included for a method for introducing a module having an ion exchanger material into a coolant container for fuel cell system.    DESCRIPTION OF DRAWING(S) - The shows a schematic representation of a container arrangement with a coolant container .    Coolant container (2)    Nozzle (3)    Protective sleeve (8)    Sealing ring (11)    Guide track. (12)