A low voltage, high continuous current DC switch assembly (16) is provided having integral switch operating means (24) with the switch (22) and a resistance means (26) which is fluid cooled. This switch assembly is particularly adapted to function as a shunt switch assembly connectable between generally parallel spaced apart electrical terminals (12, 14) which extend from or are connectable (18, 20) to an electrochemical cell (10). The switch assembly is modular in that a plurality can be assembled together as electrically parallel shunt paths (17).