×

Battery pack protective circuit for detecting overcharge or wire disconnect

  • US 7,638,977 B2
  • Filed: 11/29/2005
  • Issued: 12/29/2009
  • Est. Priority Date: 11/29/2004
  • Status: Active Grant
First Claim
Patent Images

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

  • a plurality of battery cells connected in series;

    a cell voltage detecting unit coupled to negative and positive electrodes of the battery cells through sensing wires for detecting a voltage of each of the battery cells, the cell voltage detecting unit having common circuitry for providing both;

    signals indicating a disconnection of one or more of the sensing wires, andsignals indicating an overcharging of one or more of the battery cells,wherein one of the signals indicating a disconnection of one of the sensing wires has a voltage higher than a signal corresponding to a cell voltage of a corresponding one of the battery cells which is not overcharged before said one of the sensing wires is disconnected;

    a switch unit coupled to a high current line in series between an end terminal of the plurality of battery cells and a first external terminal; and

    a control unit adapted to generate a control signal to operate the switch unit in response to both the signals indicating a disconnection of one or more of the sensing wires and the signals indicating an overcharging of one or more of the battery cells.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×