A power supply assembly is provided for a vehicle, such as a Personalized Motorized Vehicle (PMV), including a detachable mounting assembly therefor which facilitates the ease of attachment of a Power Supply Unit (PSU) to a main structural frame of the vehicle, provides a positive electrical and structural connection therebetween, and integrates the power supply assembly with the external geometry of the vehicle to provide an aesthetically pleasing external appearance. The power supply assembly includes a pair of PSUs. A segment of one PSU unit overlaps a segment of another PSU unit and another segment of one PSU overlaps a portion of the main structural frame. Electrical connectors are disposed in combination with the overlapping housing segments for electrically coupling the PSUs and at least one PSU to the vehicle. The power supply, assembly, furthermore includes a retention subassembly for structurally connecting each PSU to the main structural frame.