A new, glassy, solid electrolyte system CdI2–Ag2O–V2O5–B2O3 has been synthesized and the composition with high ionic conductivity is used as an electrolyte in a solid-state cell. The silver ion transport number of this electrolyte is nearly unity. The thermoelectric power varies inversely with absolute temperature. The discharge and current–voltage characteristics are examined for different negative and positive electrodes to evaluate the applicability of these cells as power sources for low-energy applications.