A system of communication between stacked integrated circuits powered by different voltage supply levels in a multiple cell-stacked battery pack is disclosed. The system includes a number of battery cells and a number of integrated circuits. Each integrated circuit includes a battery detecting unit, a data transceiving unit and a power acquiring unit. Since the data transceiving unit transmits signals by toggling voltage level, current flow which causes higher power consumption can be avoided. Meanwhile, the system of communication can therefore be applied to many internal communicating protocols.