High power C-size Ca-SOCl2 cells with Sr(AlCl4) + 20% SO2 electrolyte and SS can (positive can configuration) proved to have very good storage properties at room temperature, 55°C, and 70°C. When these cells were made with nickel plated cold rolled steel can (negative can configuration) they exhibited very high self discharge and failed 70 and 55°C storage tests. Postmortem analysis of this cell proved a severe corrosion of the steel can especially near the anode to can contact. Cathodic protection tests revealed an enhanced pitting corrosion of stainless steel due to its connection to a calcium foil. The mechanism of this corrosion process is discussed.