TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The indicator is present in an amount effective to render the electrolyte visually detectable when the electrolyte is exposed to electromagnetic radiation in the visible light spectrum. It is present in an amount effective to render the electrolyte visually detectable when the electrolyte is exposed to electromagnetic radiation at a frequency below the frequencies occurring in the visible light spectrum. It is present in an amount effective to render the electrolyte visually detectable when the electrolyte is exposed to electromagnetic radiation at a frequency above the visible light spectrum. The electromagnetic radiation frequency is in the infrared or ultraviolet range.Preferred Properties: The electrolyte has a voltage window that is greater than or equal to80 (preferably greater than or equal to95)% of the voltage window of a reference electrolyte, where the reference electrolyte comprises the same salt and solvent in the same molar ratio as the electrolyte above; and a conductivity that is greater than or equal to80 (preferably greater than or equal to95)% of the conductivity of the reference electrolyte.Preferred Method: The method of manufacturing the system further comprises inspecting the system under the conditions periodically after the device is installed to determine whether the electrolyte is leaking.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The indicator is a substance, preferably a dye, that reflects electromagnetic radiation, emits electromagnetic radiation, or is odiferous. The dye is one or more compounds from naphthalimide, perylene, coumarin, anthraquinone, or thioxanthene. It is preferably 1,8-naphthalimide; an organic metal chelate, preferably organic europium chelate; or aniline based heterocyclic organic acid. The concentration of the dye in the electrolyte is 5-300 (preferably 10-50) parts per million (ppm) by weight of the electrolyte. The salt comprises one or more anions from perfluoro borates, perfluoro phosphates, perfluoro sulfonates, or organic sulfonates; and one or more cations from tetraalkyl ammonium or pyridinium. It is one or more of tetraethyl ammonium tetrafluoroborate (TEABF4, preferably), methyltriethylammonium tetrafluoroborate, pyridinium tetrafluoroborate, tetraethyl ammonium hexafluorophosphate, tetraethyl ammonium hexafluoroarsenate, or imidazolium salts. The solvent is one or more of linear ether, cyclic ether, ester, carbonate, formate, lactone, nitrile, amide, sulfone, or sulfolane; one or more of alkyl carbonate, alkyl nitrile, or alkyl lactone; or one or more of acetonitrile, glutaronitrile, sulfolane, gamma-butyrolactone, propylene carbonate (PC), ethylene carbonate, or dimethyl carbonate. It is preferably propylene carbonate or acetonitrile. EXAMPLE - A TEABF4/PC electrolyte solution containing a trace amount of fluorescent organic europium chelate as an indicator was prepared. The solution with indicator was tested for cyclic voltametry and conductivity. The solution produced results similar to those of a TEABF4/PC electrolyte solution having no indicator. Thus, fluorescent organic europium chelate represented another class of indicators (organic complexes of rare earth ions) that could be used with the electrolyte.