Vehicle battery device

A vehicle battery device comprising:

• at least one battery cell mounting part accommodating a battery cell group constituted by a plurality of laminated battery cells and having a temperature control solution passage through which a temperature control solution can circulate along a lamination direction of the battery cells;
• and at least one interface box integrating connection functions between the at least one battery cell mounting part and an outside, wherein
• the at least one battery cell mounting part is connected to at least one of two opposing side surfaces in an outer surface of the at least one interface box;
• the at least one interface box has, on any outer surface other than the at least one of the two opposing side surfaces connected with the at least one battery cell mounting part, a power interface part transmitting and receiving electricity and a temperature control solution interface part transmitting and receiving the temperature control solution;
• the battery cell group of the at least one battery cell mounting part is electrically connected to the power interface part;
• and
• the temperature control solution passage of the battery cell mounting part is connected to the temperature control solution interface part so as to be capable of circulating the temperature control solution,
• wherein the at least one interface box has, between the two opposing side surfaces, a fragile part.