Electrical conductivity of (Mg,Fe)(Si,Al)O3 perovskite was measured in the multianvil press, using impedance spectroscopy at 25 GPa in the temperature range 100--1700¿C, in conjunction with M¿ssbauer spectroscopic measurements of quenched phases. Conductivity results confirm previous observations that activation enthalpies are larger at high temperatures than at low temperatures. Mobilities of charge carriers in (Mg,Fe)(Si,Al)O3 perovskite were calculated from the conductivity and M¿ssbauer data, and are consistent with Fe2+-Fe3+ electron hopping (small polaron) as the dominant conduction mechanism at low temperatures and ionic conduction at high temperatures. A laboratory-based conductivity model is constructed for the lower mantle based on the new results.