Patent ID: 8872477

Claim:
A battery pack, comprising: a battery including a plurality of battery cells; a plurality of connection lines connected between the plurality of battery cells; a control unit configured to control a charging and discharging operation of the battery; and a protection circuit unit connected to the battery and to the control unit, wherein the control unit is configured to send a signal to open the protection circuit unit when a line open condition in a connection line is detected, wherein the protection circuit unit comprises a fuse connected between a positive terminal of the battery and a charging terminal of the battery pack, a heat resistor connected between the fuse and the control unit, and a control switch connected to the heat resistor and to the control unit; a voltage sensing and balancing circuit connected to the battery and to the control unit, wherein the voltage sensing and balancing circuit is configured to sense a voltage of the battery, and to control balancing of the battery; and an analog switch unit configured to determine a voltage of an additional battery cell, wherein the analog switch unit comprises a plurality of switches connected to a flying capacitor.