A battery device has at least two interconnected battery modules and at least one cooling plate arranged between two battery modules for cooling the battery modules. A housing encases the battery device and is provided with a frame structure. The at least one cooling plate is traversed by a flow of fluid and is formed from two metal layers that are connected to one another. Additionally, the at least one cooling plate is connected fixedly at least by its ends to the frame structure and stiffens the frame structure. Thus, the battery device exhibits high power and is robust.