BATTERY UNIT

PROBLEM TO BE SOLVED: To effectively cool down a battery cell.SOLUTION: A battery unit comprises: cell rows 15 consisting of a plurality of battery cells 8 arranged in a first direction; a heat sink 10 installed as in contact with a first side face 9 among side faces of the battery cells around the first direction and forming a first flow path 28 extending in the first direction; and a flow path forming member 11 disposed between a first battery cell 8A and a second battery cell 8B orientated in the first direction and adjacent with each other among the plurality of the battery cells 8, and forming a second flow path 30 of a coolant between the first battery cell 8A and the second battery cell 8B so that a coolant G that has flown through the first flow path 28 and a coolant G that has flown around the battery cell 8A in the first direction without contacting the heat sink 10 merge and flow toward the second battery cell 8B.