A vehicle battery device comprises a box for receiving therein at least a vehicle battery, wherein a fastening platform is disposed on an inner sidewall surface of the box, and support boards is disposed at a bottom of the fastening platform; an upper lid disposed above the box and separated from the box by a waterproof plastic sheet; and at least a quick-release unit comprising a screw, washer, spring, fixing board, and wedge-shaped fixing block, with the at least a quick-release unit fastened between the fastening platform and the vehicle battery, wherein a wedge-shaped recess is disposed on an upper surface of the vehicle battery, and a wedge-shaped fastening hole is disposed in the fixing board, allowing the wedge-shaped fixing block to penetrate the wedge-shaped fastening hole and engage with the wedge-shaped recess, thereby allowing the vehicle battery to be fixed in place inside the box.