Abstract: Disclosed herein is a battery system, including: an airtight housing; a plurality of blowers disposed on a front portion and a rear portion of an interior of the airtight housing, respectively, the plurality of blowers configured to suction and discharge the air toward a middle of the airtight housing and to discharge and to suction the air to both sides of the airtight housing; a battery pack disposed between the plurality of blowers to form a plurality of rows wherein an air passageway traverses through a front portion and a rear portion of each row; a mixing section disposed between the plurality of rows in the middle of the airtight housing is configured to mix air; and a thermoelectric element disposed on an air flow path on both sides of each blower.