BATTERY CHARGING SYSTEM, A BATTERY OPERATED SYSTEM AND A METHOD FOR STATE CONTROLLED CHARGING

• US 20110148342A1
• Filed: 12/23/2009
• Published: 06/23/2011
• Est. Priority Date: 12/22/2009
• Status: Active Grant

• Current Assignee: CTEK Sweden AB (CTEK Holding AB)
• Original Assignee: Creator Teknisk Utveckling AB
• Inventors: WAHLQVIST, Bengt, MALEUS, Borje
• Granted Patent: US 8,368,345 B2
• Time in Patent Office: Days
• US Class Current: 320/101
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/007192 in response to temperature

Abstract

A battery charging system (15) and method for state controlled charging of a battery (12). The battery charging system comprises two parallel paths (16, 17) for supplying charging current to the battery (12) from two parallel sources of charging current, an energy source (13) and a controlled charging device (14). A control unit (18) is adapted to control the supply of charging current along the two paths in response to a detected state of the battery (12). If a state above a predetermined threshold is detected, the control unit (18) controls the supply of charging current such that the battery (12) receives charging current from the controlled charging device (14), but not directly from the energy source (13). The detected state of the battery may e.g. be a temperature state. The present invention allows for balancing the demands of high charging rate and long expected lifetime of the battery (12).

Claims

1. A battery charging system comprising

a first path for supplying charging current from an energy source to a battery;

a second path, in parallel with the first path, for supplying charging current from a controlled charging device to the battery;

a control unit for controlling the supply of charging current along the first and second paths in response to a detected state of the battery, wherein the control unit is configured to

communicate with a first state sensor for receiving information regarding the detected state of the battery, and to

control the supply of charging current along the first and second paths such that the battery receives charging current from the controlled charging device via the second path, and not from the energy source via the first path, in response to detection of a state of the battery above a predetermined first threshold.

2. The battery charging system according to claim 1, wherein the control unit is further configured to control the supply of charging current along the first and second paths such that no charging current is supplied to the battery from the controlled charging device or from the energy source in response to detection of a state of the battery above a predetermined second threshold.

3. The battery charging system according to claim 1, wherein the control unit is further configured to, in response to detection of a state of the battery below a predetermined third threshold, connect the first path and the second path such that the battery is supplied with charging current from both the energy source and the controlled charging device.

4. The battery charging system according to claim 1, wherein the first state sensor is a temperature sensor and the detected state of the battery is a temperature state.

5. The battery charging system according to claim 4, wherein the control unit is further configured to

communicate with a second temperature sensor for receiving information regarding a detected ambient temperature, and to

control the supply of charging current along the first and second paths in response to the detected ambient temperature.

6. The battery charging system according to claim 5, wherein said first temperature threshold is dependent on the detected ambient temperature.

7. The battery charging system according to claim 5, wherein said first temperature threshold is specified in terms of a temperature difference between the temperature of the battery and the ambient temperature.

8. A battery operated system comprising

a battery charging system according to claim 1,

an energy source connected to the first path of the battery charging system,

a controlled charging device connected to the second path of the battery charging system,

a battery connected to the first and second paths of the battery charging system, and

a first state sensor adapted to detect a state of the battery and having a communication connection with the control unit of the battery charging system.

9. The battery operated system according to claim 8, wherein the energy source is an alternator, photovoltaic panel, wind generator or generator.

10. The battery operated system according to claim 8, wherein the first state sensor is a temperature sensor, and wherein the battery operated system further comprises a second temperature sensor adapted to detect an ambient temperature and having a communication connection with the control unit of the battery charging system, wherein the control unit is further configured to control the supply of charging current along the first and second paths in response to the detected ambient temperature.

11. The battery operated system according to claim 10, wherein the first temperature threshold is dependent on the detected ambient temperature.

12. The battery operated system according to claim 10, wherein the first temperature threshold is specified in terms of a temperature difference between the temperature of the battery and the ambient temperature.

13. A method for state controlled charging of a battery comprising

detecting a state of the battery, and

supplying charging current to the battery in response to the detected state of the battery, wherein the supply of charging current to the battery is controlled such that the battery receives charging current from an energy source via a first path and from a controlled charging device via a second path, in parallel with the first path, until a state above a predetermined first threshold is detected, and when the state above the predetermined first threshold is detected, the supply of charging current to the battery is controlled such that the battery receives charging current from the controlled charging device but not from the energy source via the first path.

14. The method according to claim 13, wherein the supply of charging current to the battery is controlled such that no charging current is supplied to the battery from the controlled charging device or from the energy source when a state above a predetermined second threshold is detected.

15. The method according to claim 13, wherein the state that is detected is a temperature state of the battery, the method further comprises detecting an ambient temperature, and said first threshold depends on the detected ambient temperature.