NOVELTY - A storage-stable liquid concentrate for use with a fuel cell, comprises metal hydride compound(s), a solvent comprising polar solvent component(s), and hydroxide ion providing compound(s). After storing the concentrate for 4 weeks at 25degreesC, not greater than 2% of the metal hydride compound have decomposed.    USE - For use with a fuel cell.    ADVANTAGE - The inventive storage-stable liquid concentrate can prevent or reduce the decomposition of a fuel for a liquid fuel cell during the storage.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (A) a process for preparing a metal hydride containing liquid for use in a fuel cell from a storage-stable concentrate, comprising metal hydride compound(s) and a polar solvent and has a hydroxide ion of greater than or equal to 7 moles/L, and not greater than 2% of the metal hydride compound decomposes when the concentrate is stored for 4 weeks at 25degreesC, and a solvent at greater than or equal to 15 vol.%;    (B) a process for providing a storage-stable packaged metal hydride containing liquid for use with a fuel cell, comprising providing a container having a first compartment and second compartment(s), partially or completely filling the first compartment with a concentrate which differs from the liquid in that it comprises only the first portion of the polar solvent and in that it has a hydroxide ion concentration of at least 8 moles/L, and partially or completely filling the second compartment with the second portion of the polar solvent;    (C) a storage-stable packaged metal hydride containing the liquid obtained by the above specified process;    (D) a container filled with a metal hydride containing liquid;    (E) a refilling device for a liquid fuel cell, comprising the container; and    (F) a packaged combination for providing a metal hydride containing liquid for use with a fuel cell.    The combination comprises a first container and second container(s). The first container contains a concentrate which comprises at least one metal hydride compound, a polar solvent, and at least one hydroxide ion providing compound, and has a hydroxide ion concentration of greater than or equal to 8 moles/L, and the second container contains a solvent in an amount sufficient to result in a hydroxide ion of not greater than 7 moles/L of a mixture of the solvent in the second container and the concentrate in the first container.