ORMOCER polymer electrolytes have been tested both as separator electrolytes, and as binder elctrolyte in composite cathodes of lithium secondary batteries. The interface stability towards metallic lithium has been strongly improved by careful control of purity and conditions during polymerization. similar to 900 cycles have been obtained with utilizations decreasing from 65 to 25%, with the total discharge capacity corresponding to 330 full discharges. The charge factor during long term cycling is very close to 1 (1.004 +/- 0.006), indicating that the amount of parasitic side reactions can be minimal.