NOVELTY - The system (102) comprises multiple modular components that include multiple left-right side components (104) and front side components (106). Each side component comprises multiple openings. Each front side component is coupled to the left-right side components using a connection. A lower top component (108) is coupled to the left-right side components, and an upper top component (110) is coupled to the left-right side components. The upper top component is configured to prevent the decoupling of the lower top component from the left-right side components.    USE - Enclosure system for retaining battery system such as high voltage (HV) battery system e.g. 360V HV battery system and HV rechargeable energy storage system (RESS), for powering electric drivetrain components e.g. electric drive motors of vehicle e.g. motor cars.    ADVANTAGE - The modular enclosure system protects the battery system from internal and external forces including acceleration, deceleration, and/or vehicle impact forces, experienced during normal vehicle operation when the components are assembled. The modular enclosure system utilizes snap, compression, frictional fit, and/or other mechanical connections between the constituent components that allow the modular enclosure to be constructed with or without discrete fasteners. The material of the components does not significantly degrade over time under the normal operation of the battery system and/or the vehicle, and provides sufficient protection and/or structural integrity from forces occurring during the normal operation of the battery system and/or the vehicle. The components are designed to withstand forces resulting from vehicle collisions or impacts. The alignment of the components is facilitated and/or the structural support is provided to the assembled enclosure. The portions of components having less rigidity is selectively deformed to facilitate assembly of the enclosure using snap, compression, frictional fit, and/or other mechanical connections. The openings facilitate the assembly of the modular enclosure by providing positions in which the first side component is manipulated.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the enclosure system.    Enclosure system (102)    Left-right side components (104)    Front side components (106)    Lower top component (108)    Upper top component (110)