Protective circuit of battery pack

A protective circuit of a battery pack, the protective circuit comprising:

• at least one battery cell;
• a cell voltage detecting unit coupled to negative and positive electrodes of the battery cell through a sensing wire so as to detect a voltage of the battery cell;
• a switch unit coupled to a high current line in series between one terminal of the battery cell and an external terminal;
• and
• a control unit adapted to receive a signal from the cell voltage detecting unit and generate a predetermined control signal based on the signal of the cell voltage detecting unit, wherein the signal of the cell voltage detecting unit is based on the detected voltage, in order to operate the switch unit when the battery cell is overcharged.

A method of determining whether a sensing wire in a protective circuit of a battery pack is disconnected, the method comprising:

• detecting a voltage of a battery cell;
• receiving a signal indicative of whether a predetermined sensing wire is disconnected, wherein the signal is based on the detected voltage;
• and
• in response to the received signal indicating that the predetermined sensing wire is disconnected, generating a predetermined control signal to stop the charge of the battery cell.

A method of determining whether a sensing wire in a protective circuit of a battery pack is overcharged, the method comprising:

• detecting a voltage of a battery cell;
• receiving a signal indicative of whether the battery cell is overcharged;
• and
• in response to the received signal indicating that the battery cell is overcharged, wherein the signal is based on the detected voltage generating a predetermined control signal to stop the charge of the battery cell.