US Patent 11329343 Battery device for vehicle

A battery device for a vehicle, which can be miniaturized while including ancillary instruments such as a relay device. The battery device is mounted in a lower portion of a vehicle, and including a battery case; a plurality of battery modules accommodated in the battery case and arranged such that at least some of the battery modules are stacked in a plurality of levels; and a first relay device that switches connection and disconnection between external electric devices and the battery modules. The first relay device is disposed on a side in a vehicle width direction of a portion where the battery modules are stacked in a plurality of levels.