A capacitor is described. The capacitor comprises a first casing member having a first face wall extending to a first surrounding sidewall in turn extending to a first annular edge defining a first open end. A second casing member has a second face wall extending to a second surrounding sidewall in turn extending to a second annular edge defining a second open end. The second casing member is supported on the first annular edge to thereby close the first open end of the first casing member and provide a first capacitor enclosure comprising the first and second casing members in a stacked relationship. A cover is secured to the second annular edge to close the second casing member and provide a second capacitor enclosure. An anode, for example of tantalum, and a cathode active material, for example of ruthenium oxide, reside in capacitive association with each other inside each of the first and second capacitor enclosures. A working electrolyte is also contained in the capacitor enclosures. Finally, leads extend from each anode through insulative seals structures supported by the casing members for making electrical connection to the capacitor.