An electric vehicle power supply includes a housing, a power supply, and a plurality of fasteners. The housing defines an internal cavity and has inwardly protruding tabs that extend into the cavity. The power assembly has a front cover and an end cover. The power assembly also has an array of electrical switching units arranged horizontally between the front and end covers. The front and end covers have outwardly protruding tabs. Each of the plurality of fasteners extend vertically, engage one inwardly protruding tab, and engage one outwardly protruding tab to secure the power assembly to the housing.