The temperature dependence on the electrolyte stability of LiAlCl 4 and LiGaCl 4 in sulfur dioxide on a platinum electrode was studied by cyclic voltammetry and conductivity methods, whereas the temperature dependence on the electrolyte stability and electrode film conductivity on a lithium electrode was studied by the a.c. impedance technique. LiGaCl 4 with a better conductivity behavior is more stable than LiAlCl 4. For both electrolytes below 25 °C, the conductivity increases with increasing temperature, but above 25 °C it decreases with increasing temperature. The implication of an ionic transport mechanism change is discussed.