Apparatus and method for monitoring battery pack

• US 7,570,025 B2
• Filed: 11/29/2005
• Issued: 08/04/2009
• Est. Priority Date: 11/29/2004
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Kim, Woo Choul
• Primary Examiner(s): Berhane; Adolf
• Assistant Examiner(s): Fantu; Yalkew
• Application Number:
  US11/291,113
• Publication Number:
  US 20060139007A1
• Time in Patent Office: 1,344 Days
• Field of Search: 320/112, 320/132, 320/149, 320/150
• US Class Current: 320/150
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

A battery pack monitoring apparatus for and method of monitoring various characteristics of the battery pack such that when the battery pack malfunctions, the exact reason for the malfunction can be grasped. The apparatus includes a bare cell adapted to be charged/discharged with a predetermined voltage; a voltage sensor for sensing a charging/discharging voltage of the bare cell and outputting the voltage as a predetermined electrical signal; a current sensor for sensing a charging/discharging current of the bare cell and outputting the current as a predetermined electrical signal; a control unit, a current sensor, and a data storage unit.

Claims

1. A battery pack monitoring apparatus comprising:

a bare cell adapted to be charged or discharged with a voltage;

a voltage sensor adapted to sense a charging voltage or a discharging voltage of the bare cell and output a sensed charging voltage or a sensed discharging voltage as a first electrical signal;

a current sensor adapted to sense a charging current or a discharging current of the bare cell and output a sensed charging current or a sensed discharging current as a second electrical signal;

a charging switch and a discharging switch coupled between the bare cell and an external terminal;

a switch temperature sensor near the charging switch and the discharging switch, the switch temperature sensor adapted to sense a temperature of the charging switch or the discharging switch, and convert the sensed temperature into a third electrical signal;

a control unit adapted to convert the first electrical signal, the second electrical signal, and the third electrical signal into a respective first digital signal, second digital signal and a third digital signal, operate and process the first digital signal, the second digital signal and the third digital signal in accordance with a control command, and calculate a battery capacity with reference to the first electrical signal, the second electrical signal and the third electrical signal; and

a data storage unit adapted to store sensed charging voltage data or sensed discharging voltage data, sensed charging current data or sensed discharging current data, sensed temperature data of the charging switch or the discharging switch and calculated battery capacity data of the bare cell processed by the control unit.

2. The battery pack monitoring apparatus as claimed in claim 1, further comprising a cell temperature sensor near the bare cell to sense a temperature of the bare cell, convert the temperature of the bare cell into a fourth electrical signal, and output the fourth electrical signal to the control unit.

3. The battery pack monitoring apparatus as claimed in claim 2, wherein the control unit is adapted to calculate the battery capacity with reference to the sensed temperature of the bare cell.

4. The battery pack monitoring apparatus as claimed in claim 1, wherein the control unit is adapted to update and store the sensed charging voltage data when the sensed charging voltage is larger than an existing charging voltage.

5. The battery pack monitoring apparatus as claimed in claim 1, wherein the control unit is adapted to update and store the sensed discharging voltage data when the sensed discharging voltage is smaller than an existing discharging voltage.

6. The battery pack monitoring apparatus as claimed in claim 2, wherein the control unit is adapted to update and store the sensed temperature data of the bare cell when the sensed temperature of the bare cell is higher than an existing cell temperature.

7. The battery pack monitoring apparatus as claimed in claim 1, wherein the charging switch or the discharging switch is coupled to at least one protective circuit to toggle on/off the charging switch or the discharging switch in accordance with an input of the first electrical signal from the voltage sensor or the second electrical signal from the current sensor.

8. The battery pack monitoring apparatus as claimed in claim 1,

wherein the control unit is coupled to a communication interface unit, and

wherein the communication interface unit is adapted to transmit the sensed charging voltage data or the sensed discharging voltage data, the sensed charging current data or the sensed discharging current data, the sensed temperature data of the charging switch or the discharging switch and the calculated battery capacity data of the bare cell processed by the control unit.

9. The battery pack monitoring apparatus as claimed in claim 8, wherein the communication interface unit adopts a RS-232C (Recommended Standard 232 Revision C) mode.

10. The battery pack monitoring apparatus as claimed in claim 2, wherein the cell temperature sensor is selected from the group consisting of:

a thermistor, a winding resistor-type sensor, a wide area resistance sensor, a semiconductor diode sensor, a medal core-type sensor, and a thermocouple.

11. The battery pack monitoring apparatus as claimed in claim 8, wherein the communication interface unit is coupled to an external set, wherein the external set comprises:

a set communication interface unit coupled to the communication interface unit of the battery pack;

a set control unit adapted to process signals inputted from the set communication interface unit; and

a set data storage unit adapted to store data regarding the battery pack under control of the set control unit, the data including the charging voltage data or the discharging voltage data, charging current data or discharging current data, the bare cell temperature data, the temperature data of the charging switch or the discharging switch, and the battery capacity.

12. The battery pack monitoring apparatus as claimed in claim 11,

wherein the set control unit has a set display unit coupled thereto to display the data regarding the battery pack stored on the set data storage unit.

20. The battery pack monitoring apparatus as claimed in claim 2, wherein the control unit is adapted to update and store the sensed charging current data when the sensed charging current is smaller than an existing charging current.

21. The battery pack monitoring apparatus as claimed in claim 2, wherein the control unit is adapted to update and store the sensed discharging current data when the sensed discharging current is larger than an existing discharging current.

22. The battery pack monitoring apparatus as claimed in claim 2, wherein the control unit is adapted to update and store at least one switch temperature data when the temperature of the charging switch or the discharging switch is higher than an existing switch temperature.

13. A method for monitoring a battery pack comprising:

sensing a charging voltage of a bare cell and outputting a sensed charging voltage signal;

sensing a charging current of the bare cell and outputting a sensed charging current signal;

sensing a temperature of the bare cell and outputting a sensed temperature of the bare cell signal;

sensing a temperature of a charging switch or a discharging switch and outputting a sensed temperature of the charging switch or the discharging switch signal at an interval when the bare cell is charged or discharged; and

storing sensed charging voltage data, sensed charging current data, sensed temperature data of the bare cell and sensed temperature data of the charging switch or the discharging switch together with a calculated battery capacity data.

14. The method as claimed in claim 13, wherein storing comprises:

updating existing charging voltage data to the sensed charging voltage data when the sensed charging voltage is larger than an existing charging voltage, and storing the sensed charging voltage data;

updating existing charging current data to the sensed charging current data when the sensed charging current is smaller than an existing charging current, and storing the sensed charging current data;

updating existing bare cell temperature data to the sensed bare cell temperature data when the sensed bare cell temperature is higher than an existing bare cell temperature, and storing the sensed bare cell temperature data;

updating existing temperature data of the charging switch or the discharging switch to the sensed temperature data of the charging switch or the discharging switch when the sensed temperature of the charging switch or the discharging switch is higher than an existing temperature of the charging switch or the discharging switch, and storing the sensed temperature data of the charging switch or the discharging switch; and

updating existing battery capacity data to the calculated battery capacity data when the calculated battery capacity is larger than an existing battery capacity, and storing the calculated battery capacity data.

15. The method as claimed in claim 13, wherein the interval is approximately 10-30 minutes.

16. The method as claimed in claim 13, further comprising transmitting the charging voltage data, the charging current data, the temperature data of the charging switch or the discharging switch, and the battery capacity data to and from an external set.

17. A method for monitoring a battery pack comprising:

sensing a discharging voltage of a bare cell and outputting a sensed discharging voltage signal,

sensing a discharging current of the bare cell and outputting a sensed discharging current signal;

sensing a temperature of the bare cell and outputting a sensed temperature signal;

sensing a temperature of a charging switch or a discharging switch at an interval when the bare cell is coupled to an external set and outputting a sensed temperature of a charging switch or a discharging switch signal; and

storing sensed discharging voltage data of the bare cell, sensed discharging current data, sensed temperature data of the bare cell, sensed temperature data of the charging switch or the discharging switch and previously-calculated battery capacity data.

18. The method as claimed in claim 17, wherein storing comprises:

updating existing discharging voltage data to the sensed discharging voltage data when the sensed discharging voltage is smaller than an existing discharging voltage, and storing the sensed discharging voltage data;

updating existing discharging current data to the sensed discharging current data when the sensed discharging current is larger than an existing discharging current, and storing the sensed discharging current data;

updating existing bare cell temperature data to the sensed bare cell temperature data when the sensed bare cell temperature is higher than an existing bare cell temperature, and storing the sensed bare cell temperature data;

updating existing temperature data of the charging switch or the discharging switch to the sensed temperature data of the charging switch or the discharging switch, when the sensed temperature of the charging switch or the discharging switch is higher than an existing temperature of the charging switch or the discharging switch, and storing the sensed temperature data of the charging switch or the discharging switch; and

updating existing battery capacity data to the calculated battery capacity data when a calculated battery capacity is smaller than an existing battery capacity, and storing the calculated battery capacity data.

19. The method as claimed in claim 17, further comprising transmitting the discharging voltage data of the bare cell, the discharging current data, the temperature data of the charging or discharging switch, and the battery capacity data to and from the external set.