A cell controller includes: a balancing unit which performs balancing of states of charge of a plurality of secondary batteries by discharging or charging each of the plurality of secondary batteries; a first timer which measures an elapsed time after a start of the balancing; a receiving unit which receives a balancing command signal including information regarding balancing times for the secondary batteries; and a first control unit which controls the balancing unit on a basis of the elapsed time after the start of the balancing, and the balancing command signal, the elapsed time being measured by the first timer and the balancing command signal being received by the receiving unit, in which the receiving unit receives the information on the plurality of secondary batteries through the single balancing command signal.