The aim of this study was to determine an influence of lithium excess in Li1 + deltaMn2 - deltaO4 spinels (in the 0 less than or equal to delta less than or equal to 0.32 range) on their transport and structural properties. The additional lithium atoms take Mn positions causing in the lattice parameter diminution and disappearance of the phase transition observed for the stoichiometric Li1Mn2O4 manganese spinel. Low-temperature (230-330 K) measurements of electrical conductivity and thermoelectric power indicate rather minor influence of the excess lithium on transport properties in this system.