HYBRID BATTERY AND FULL CHARGE CAPACITY CALCULATION METHOD THEREOF

• US 20080048621A1
• Filed: 08/22/2007
• Published: 02/28/2008
• Est. Priority Date: 08/24/2006
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Yun, Changyong
• Granted Patent: US 7,737,660 B2
• Time in Patent Office: Days
• US Class Current: 320/136
• CPC Class Codes: G01R 31/3832 without measurement of battery voltage
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• 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 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A hybrid battery and full charge capacity calculation method thereof. A full charge capacity is calculated for each battery at at least two discharge voltage levels, and a total full charge capacity is calculated by adding the calculated full charge capacity of the discharging battery to a full charge capacity of a non-discharging battery. A hybrid battery includes: a first power source and a second power source; a sense resistor that senses and outputs current information of at least one of the first power source or the second power source; and a fuel gauge circuit that calculates a first accumulated discharge amount using the current information from the sense resistor when a voltage of a currently discharging one of the first or second power source reaches a first discharge voltage level, and to add a first capacity corresponding to the first discharge voltage level to the first accumulated discharge amount.

Claims

1. A hybrid battery comprising:

a first power source adapted to output a first voltage;

a second power source, which is parallel to the first power source and adapted to output a second voltage;

a sense resistor, which is in series with the first power source and the second power source and adapted to sense and output current information of at least one of the first power source or the second power source; and

a fuel gauge circuit adapted to calculate a first accumulated discharge amount using the current information from the sense resistor when a voltage of a currently discharging one of the first power source or the second power source reaches a first discharge voltage level, and to add a first capacity corresponding to the first discharge voltage level to the first accumulated discharge amount to calculate a first full charge capacity.

2. The hybrid battery as claimed in claim 1, wherein the first capacity is calculated by multiplying a previous full charge capacity with a percentage of remaining capacity corresponding to the first discharge voltage level.

3. The hybrid battery as claimed in claim 1, wherein the fuel gauge circuit is further adapted to calculate a second accumulated discharge amount using the current information from the sense resistor when the voltage of the currently discharging one of the first power source or the second power source reaches a second discharge voltage level, wherein the second discharge voltage level is lower than the first discharge voltage level, and

to calculate a second full charge capacity by adding a second capacity corresponding to the second discharge voltage level to the second accumulated discharge amount.

4. The hybrid battery as claimed in claim 3, wherein the second capacity is calculated by multiplying a previous full charge capacity with a percentage of remaining capacity corresponding to the second discharge voltage level.

5. The hybrid battery as claimed in claim 1, wherein the fuel gauge circuit comprises:

a first discharge voltage level detector for detecting at least two discharge voltage levels different from each other while the first power source is discharging;

a second discharge voltage level detector for detecting at least two discharge voltage levels different from each other while the second power source is discharging;

an accumulated discharge amount calculator for calculating an accumulated discharge amount using the current information from the sense resistor; and

a capacity calculator for calculating a full charge capacity by adding remaining capacity corresponding to one of the discharge voltage levels to the accumulated discharge amount when the discharge voltage level obtained from the first discharge voltage level detector or the second discharge voltage level detector reaches a preset discharge voltage level.

6. The hybrid battery as claimed in claim 5, wherein the capacity calculator calculates the first capacity by multiplying a percentage of remaining capacity corresponding to the discharge voltage level with a previous full charge capacity.

7. The hybrid battery as claimed in claim 1, wherein the fuel gauge circuit, after calculating the full charge capacity of the discharging one of the first power source or the second power source, adds a previously stored full charge capacity of a currently non-discharging one of the first power source or the second power source to calculate a new total full charge capacity.

8. The hybrid battery as claimed in claim 1, wherein the first power source and the second power source comprise rechargeable batteries.

9. The hybrid battery as claimed in claim 1, wherein at least one of the first power source or the second power source comprises at least one of a cylindrical lithium ion battery, a rectangular lithium ion battery, a pouch type lithium polymer battery or a pouch type lithium ion battery.

10. The hybrid battery as claimed in claim 1, wherein the first power source and the second power source are different from each other in at least one of shape, chemical property, capacity or charge/discharge voltage.

11. A method of calculating a full charge capacity of a hybrid battery comprising a first power source and a second power source, which are different from each other in at least one of shape, chemical property, capacity or charge/discharge voltage, the method comprising:

calculating a first accumulated discharge amount of the first power source while the first power source is discharging, and determining whether a first discharge voltage level of the first power source has been reached;

adding the first accumulated discharge amount of the first power source, which has been accumulated until the first discharge voltage level was reached for the first power source, to a first capacity of the first power source corresponding to the first discharge voltage level of the first power source, to calculate a first full charge capacity of the first power source;

calculating a second accumulated discharge amount of the first power source while the first power source is discharging, and determining whether a second discharge voltage level of the first power source, which is lower than the first discharge voltage level of the first power source, has been reached; and

adding the second accumulated discharge amount of the first power source, which has been accumulated until the second discharge voltage level was reached for the first power source, to a second capacity of the first power source corresponding to the second discharge voltage level of the first power source, to calculate a second full charge capacity of the first power source.

12. The method as claimed in claim 11, wherein the first capacity or the second capacity of the first power source is obtained, respectively, by multiplying a percentage of remaining capacity of the first power source corresponding to the respective first discharge voltage level or the second discharge voltage level of the first power source with a previous full charge capacity of the first power source.

13. The method as claimed in claim 11, wherein after respective calculation of the first full charge capacity or the second full charge capacity of the first power source, further comprising storing the first full charge capacity or the second full charge capacity, respectively, of the first power source in a memory.

14. The method as claimed in claim 11, wherein, after respective calculation of the first full charge capacity or the second full charge capacity of the first power source, further comprising adding the first full charge capacity or the second full charge capacity, respectively, of the first power source to a previously stored full charge capacity of the second power source, to calculate a total full charge capacity.

15. A method of calculating a full charge capacity of a hybrid battery comprising a first power source and a second power source, which are different from each other in at least one of shape, chemical property, capacity or charge/discharge voltage, the method comprising:

calculating a first accumulated discharge amount of the second power source while the second power source is discharging, and determining whether a first discharge voltage level of the second power source has been reached;

adding the first accumulated discharge amount of the second power source, which has been accumulated until the first discharge voltage level was reached for the second power source, to a first capacity of the second power source corresponding to the first discharge voltage level of the second power source, to calculate a first full charge capacity of the second power source;

calculating a second accumulated discharge amount of the second power source while the second power source is discharging, and determining whether a second discharge voltage level of the second power source, which is lower than the first discharge voltage level of the second power source, has been reached; and

adding the second accumulated discharge amount of the second power source, which has been accumulated until the second discharge voltage level was reached for the second power source, to a second capacity of the second power source corresponding to the second discharge voltage level of the second power source, to calculate a second full charge capacity of the second power source.

16. The method as claimed in claim 15, wherein the first capacity or the second capacity of the second power source is obtained, respectively, by multiplying a percentage of remaining capacity of the second power source corresponding to the respective first discharge voltage level or the second discharge voltage level of the second power source with a previous full charge capacity of the second power source.

17. The method as claimed in claim 15, wherein after respective calculation of the first full charge capacity or the second full charge capacity of the second power source, further comprising storing the first full charge capacity or the second full charge capacity, respectively, of the second power source in the memory.

18. The method as claimed claim 15, wherein, after respective calculation of the first full charge capacity or the second full charge capacity of the second power source, further comprising adding the first full charge capacity or the second full charge capacity, respectively, of the second power source to a previously stored full charge capacity of the first power source, to calculate another total full charge capacity.