A wireless control system, comprising: a master configured to wirelessly transmit a first command packet; and a plurality of slaves (200; 200_1...200_N) configured to monitor a condition of a plurality of battery modules, wherein the master is configured to allocate and store an identification, ID, to each one of the plurality of slaves (200, 200_1...200_N), wherein an ID of higher rank is allocated to a slave having a shorter communication distance with the master, wherein each of the plurality of slaves is configured to wirelessly transmit a response packet including the identification, ID, of the corresponding slave in response to the first command packet when receiving the first command packet, the master is configured to set, as a first group, each slave from which the master wirelessly received the response packet within a predetermined period of time from a time point at which the first command packet was transmitted, the master is configured to set, as a second group, each slave not set as the first group among the plurality of slaves, corresponding to the slaves from which the master did not receive the response packet, the master is configured to wirelessly transmit a second command packet when at least one of the plurality of slaves belongs to the second group, and the second command packet includes the ID of each slave belonging to the second group, wherein each of the plurality of slaves is configured to: determine a relative rank of the ID of the corresponding slave among all the IDs included in the second command packet when the second command packet includes the ID of the corresponding slave, and wirelessly transmit the response packet at a time slot allocated to the relative rank, wherein the master is configured to wirelessly transmit the second command packet with a first amplified signal strength associated with an ID of a lowest rank among the IDs of each slave belonging to the second group. a master configured to wirelessly transmit a first command packet; and a plurality of slaves (200; 200_1...200_N) configured to monitor a condition of a plurality of battery modules, wherein the master is configured to allocate and store an identification, ID, to each one of the plurality of slaves (200, 200_1...200_N), wherein an ID of higher rank is allocated to a slave having a shorter communication distance with the master, wherein each of the plurality of slaves is configured to wirelessly transmit a response packet including the identification, ID, of the corresponding slave in response to the first command packet when receiving the first command packet, the master is configured to set, as a first group, each slave from which the master wirelessly received the response packet within a predetermined period of time from a time point at which the first command packet was transmitted, the master is configured to set, as a second group, each slave not set as the first group among the plurality of slaves, corresponding to the slaves from which the master did not receive the response packet, the master is configured to wirelessly transmit a second command packet when at least one of the plurality of slaves belongs to the second group, and the second command packet includes the ID of each slave belonging to the second group, wherein each of the plurality of slaves is configured to: determine a relative rank of the ID of the corresponding slave among all the IDs included in the second command packet when the second command packet includes the ID of the corresponding slave, and wirelessly transmit the response packet at a time slot allocated to the relative rank, wherein the master is configured to wirelessly transmit the second command packet with a first amplified signal strength associated with an ID of a lowest rank among the IDs of each slave belonging to the second group. determine a relative rank of the ID of the corresponding slave among all the IDs included in the second command packet when the second command packet includes the ID of the corresponding slave, and wirelessly transmit the response packet at a time slot allocated to the relative rank, wherein the master is configured to wirelessly transmit the second command packet with a first amplified signal strength associated with an ID of a lowest rank among the IDs of each slave belonging to the second group.