The utility model discloses a battery box. The battery box comprises a box body and a battery pack arranged in the box body, wherein a left side plate and a right side plate of the box body are air inlet plates; air inlets are formed in the parts, which are close to the rear plate of the box body, of the air inlet plates; the front plate of the box body is an air-out plate; partition plates which are pressed against the left side plate and the right side plate respectively are arranged between the battery pack and the front plate in the box body; batteries in the battery pack are arranged in three columns along the horizontal direction of the box body; an air outlet is formed at the position between each two columns of the batteries on the partition plates; a clearance is reserved between each two batteries in each column; and clearances are reserved between two columns of batteries on two sides of the box body and the corresponding side plates, and heat preservation materials and heating components are arranged in the clearances. By the device, the clearances form a ventilation channel in the box body, and cooling air circulates around the batteries through the ventilation channel, so that the radiating surface of each battery is increased, and difference in temperature among the batteries is effectively reduced.