An air plenum assembly includes a first plenum for cooling, where the first plenum includes an inlet for air intake located at a first side of the first plenum. The air plenum assembly further includes a second plenum for exhausting heated air, where the second plenum includes an outlet for exhausting air located at a first side of the second plenum. The air plenum assembly further incudes a first aperture located on a first side of the first plenum for directing air from the inlet at the first side of the first plenum to a first compartment and includes a first vent located on a first side of the second plenum for exhausting air away from the first compartment towards the outlet at the first side of the second plenum. The first compartment is isolated from surrounding battery compartments by at least two thermal separators.