A frame assembly for an automobile and method of assembling same. The frame assembly includes a battery housing at least partially integral with an automobile frame. The frame includes longitudinal beams that extend between front frame rails and rear frame rails. The battery housing includes two portions, a upper cover integrated with the longitudinal beams and a base plate that connects to the upper cover or the longitudinal beams with a releasable connection. The base plate includes a connection flange that includes at least one seal. When connected, at least one battery module is enclosed in the battery housing.