Apparatus and method for monitoring battery pack

• US 20060139007A1
• Filed: 11/29/2005
• Published: 06/29/2006
• 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
• Granted Patent: US 7,570,025 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• 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 predetermined 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 predetermined 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 predetermined electrical signal;

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

a data storage unit adapted to store the sensed charging voltage or the sensed discharging voltage, the sensed charging current or the sensed discharging current, and the calculated battery capacity 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 positioned near the bare cell to sense a temperature of the bare cell, convert the temperature of the bare cell into a third predetermined electrical signal, and output the third predetermined electrical signal to the control unit;

and

a charging switch and a discharging switch coupled to between the bare cell and an external terminal, a switch temperature sensor positioned near the charging switch and the discharging switch, the switch temperature sensor adapted to sense the temperatures of the charging switch or the discharging switch, convert the temperatures into a fourth predetermined electrical signal, and output the fourth 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 temperature of the bare cell and the temperature of the charging switch or the discharging switch.

4. The battery pack monitoring apparatus as claimed in claim 2, wherein the data storage unit is adapted to store the temperature of the bare cell sensed by the cell temperature sensor, and to store the temperature of the charging switch or the discharging switch that is sensed by the switch temperature sensor.

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

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

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

8. The battery pack monitoring apparatus as claimed in claim 2, 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 input of the first predetermined electrical signal from the voltage sensor or the second predetermined electrical signal from the current sensor.

9. The battery pack monitoring apparatus as claimed in claim 4,

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

wherein the communication interface unit is adapted to transmit data stored on the data storage unit to an external set,

wherein the data includes charging voltages or discharging voltages, charging currents or discharging currents, the bare cell temperature, the temperatures of the charging switch and the temperature of the discharging switches, and the battery capacity.

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

11. 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.

12. The battery pack monitoring apparatus as claimed in claim 9, 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, wherein the data includes the charging voltage or the discharging voltage, charging currents or discharging currents, the bare cell temperature, the temperature of the charging switch and the temperature of the discharging switch, and battery capacity.

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

wherein the set control unit has a set display unit coupled thereto to display data regarding the battery pack stored on the set data storage unit, the data including the charging voltage or the discharging voltage, the charging current or the discharging current, the bare cell temperature, the temperature of the charging switch or the temperature of the discharging switch, and the battery capacity.

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

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

23. 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 when the at least one switch temperature is higher than an existing switch temperature.

14. A method for monitoring a battery pack comprising:

sensing a charging voltage and outputting a sensed charging voltage, sensing a charging current and outputting a sensed charging current, sensing a temperature of a rechargeable bare cell and outputting a temperature of a charging switch or a discharging switch at a predetermined interval when the rechargeable bare cell is coupled to a charger; and

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

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

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

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

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

updating existing temperatures of the charging and discharging switches to sensed temperatures of the charging and discharging switches when the sensed temperatures are higher than the existing temperatures, and storing the sensed temperatures; and

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

16. The method as claimed in claim 14, wherein the interval is approximately 10-30 minutes.

17. The method as claimed in claim 14, further comprising transmitting the charging voltage, charging current, the temperature of the charging switch or the discharging switch, and the battery capacity to and from an external set.

18. A method for monitoring a battery pack comprising:

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

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

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

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

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

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

updating existing temperatures of the charging and discharging switches to sensed temperatures of the charging and discharging switches, when the sensed temperatures are higher than the existing temperatures, and storing the sensed temperatures; and

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

20. The method as claimed in claim 18, further comprising transmitting the discharging voltage of the bare cell, the discharging current, the temperature of the charging or discharging switch, and the battery capacity to and from an external set.