A power battery device includes: a battery tray having a positioning member provided on the upper surface thereof; and a plurality of battery modules disposed on the battery tray and arranged in at least two layers in an up-down direction, each battery module comprising: a housing having a first positioning portion disposed on the upper surface of the housing and a second positioning portion disposed on the lower surface of the housing; a battery disposed within the housing, the first positioning portion of the housing in a lower layer is matched with the second positioning portion of the housing in an upper layer, and the battery modules in the lowermost layer of the battery modules are positioned by the positioning member.