Electrical conductivity, interaction with lithium metal and apparent Li+ transference number of gel polyelectrolytes was examined by the impedance spectroscopy and the dc polarisation of cells. Gel polyelectrolytes were obtained by crosslinking of plasticized lithium salts derived from comb-like half ester of maleic acid copolymer. Two gels contained additives: either BF3 as an agent complexing carboxylic anions or LiN(CF3SO2)(2) salt as a source of additional lithium ions. The measured impedance spectra of cells Li/gel/Li were simulated by an equivalent circuit. The time evolution of the circuit parameters indicated growth of passivation layer and degradation of the electrolyte. In all studied gels, the apparent Li+ transference number had low values, which decreased upon time of storage of cells with Lithium electrodes. Probably small ions are formed upon chemical interaction between lithium and dimethoxyethylenesulfoxide-the polar solvent used as a plasticizer.