Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. These include Li-TiS2, Li-V2O5, and Li-LiMn2O4 cells with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The realization of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li3.3PO3.8N0.22 and a conductivity at 25-degrees-C of 2 muS/cm. The thin-film cells have been cycled at 100% depth of discharge using current densities of 5 to 100 muA/cm2. Over most of the charge-discharge range, the internal resistance appears to be dominated by the cathode, and the major source of the resistance is the diffusion of Li+ ions from the electrolyte into the cathode. Chemical diffusion coefficients were determined from ac impedance measurements.