An apparatus is provided that relates to an electrochemical cell assembly. The apparatus is capable of controlling water loss from a fuel cell, at least in part by separating gas and liquid fluid flows. A variety of flow designs are provided that separate liquid electrolyte flow from reagent gas flow. Some flow designs may be suitable for one or more of fuel cells, rechargeable fuel cells, and batteries such as metal hydride batteries. Furthermore, some embodiments may include a single electrochemical cell, or plurality of cells arranged in parallel or in series. Some embodiments may also relate to methods of mitigating water loss from an electrochemical cell assembly.