SAFETY IMPROVED MULTI BATTERY PACK SYSTEM AND CONTROL METHOD THEREOF, AND BATTERY PACK USING THE SAME

摘要

A multi-battery pack system is provided to control a great number of slave battery packs while not increasing the load to a master battery pack, and to prevent generation of undesired overcurrent-protecting action. A multi-battery pack comprises: a cell group having a plurality of cells connected in series; a voltage detection circuit for sensing the voltage of each battery and outputting the voltage as a total voltage; a switching device(904) for turning on/off the connection between the cell group and output terminals; a control section receiving the total voltage of at least one slave battery pack and the total voltage from the voltage detection circuit to calculate a target voltage, transmitting the target voltage to each slave battery pack, and comparing the target voltage to the total voltage of itself to control the switching device based on the results; and a current buffering circuit(901,1001) for sensing the charging or discharging current of the battery pack and carrying out an action of increasing the on-resistance of the switching device if the sensed current exceeds the limit value by side feedback control, thereby limiting the charging current or discharging current to a constant current.