A heater control system, which is a system configured to control heaters of at least two battery packs connected in parallel, comprising a plurality of battery packs comprising a single master pack and at least two slave packs, the master pack comprising: at least two heating groups comprising first and second cell arrays (112,114) each comprising a plurality of cells and a heater provided between and configured to heat the first and second cell arrays (112,114), wherein the heater has a pad shape, and first and second cell arrays (112,114) are respectively arranged on a upper and a lower portion of the heater; a master communication unit configured to connecting communication between the slave packs; and an operation determination unit configured to determine whether to operate the heaters of the slave pack on the basis of temperature data received from each slave pack through the master communication unit and transmit a heater operation control signal of the heaters in the slave pack according to a determination result, the slave pack comprising: at least two heating groups each comprising first and second ell arrays (212, 214) comprising a plurality of cells, and a heater provided between the first and second cell arrays (212, 214) and configured to heat the first and second cell arrays (212, 214), wherein the heater has a pad shape, and first and second cell arrays (212, 214) are respectively arranged on a upper and a lower portion of the heater; a slave communication unit configured to connect communication with the master pack; a temperature data calculation unit configured to measure the temperatures of the first and second cell arrays (212, 214) at certain period intervals and calculate temperature data for determining whether to operate heaters in the slave pack on the basis of the measured temperature; and a first heater operation control unit configured to control an operation of each heater in response to the heater operation signal received from the master pack. at least two heating groups comprising first and second cell arrays (112,114) each comprising a plurality of cells and a heater provided between and configured to heat the first and second cell arrays (112,114), wherein the heater has a pad shape, and first and second cell arrays (112,114) are respectively arranged on a upper and a lower portion of the heater; a master communication unit configured to connecting communication between the slave packs; and an operation determination unit configured to determine whether to operate the heaters of the slave pack on the basis of temperature data received from each slave pack through the master communication unit and transmit a heater operation control signal of the heaters in the slave pack according to a determination result, the slave pack comprising: at least two heating groups each comprising first and second ell arrays (212, 214) comprising a plurality of cells, and a heater provided between the first and second cell arrays (212, 214) and configured to heat the first and second cell arrays (212, 214), wherein the heater has a pad shape, and first and second cell arrays (212, 214) are respectively arranged on a upper and a lower portion of the heater; a slave communication unit configured to connect communication with the master pack; a temperature data calculation unit configured to measure the temperatures of the first and second cell arrays (212, 214) at certain period intervals and calculate temperature data for determining whether to operate heaters in the slave pack on the basis of the measured temperature; and a first heater operation control unit configured to control an operation of each heater in response to the heater operation signal received from the master pack. at least two heating groups each comprising first and second ell arrays (212, 214) comprising a plurality of cells, and a heater provided between the first and second cell arrays (212, 214) and configured to heat the first and second cell arrays (212, 214), wherein the heater has a pad shape, and first and second cell arrays (212, 214) are respectively arranged on a upper and a lower portion of the heater; a slave communication unit configured to connect communication with the master pack; a temperature data calculation unit configured to measure the temperatures of the first and second cell arrays (212, 214) at certain period intervals and calculate temperature data for determining whether to operate heaters in the slave pack on the basis of the measured temperature; and a first heater operation control unit configured to control an operation of each heater in response to the heater operation signal received from the master pack.