SYSTEMS AND METHODS FOR PERFORMING BATTERY MANAGEMENT

• US 20160190830A1
• Filed: 12/31/2014
• Published: 06/30/2016
• Est. Priority Date: 12/31/2014
• Status: Active Grant

• Current Assignee: Meridian Design Incorporated, Shorai, Inc. (XNRGI, Inc.)
• Original Assignee: Meridian Design Incorporated, Shorai, Inc. (XNRGI, Inc.)
• Inventors: KUHLMANN, KURT, RADFORD, DAVID, HIGBEE, SHAWN, MATTHEWS, DAN
• Granted Patent: US 9,847,658 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 13/00001 characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00026 involving a local wireless network, e.g. Wi-Fi, ZigBee or Bluetooth
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 10/40 Display of information, e.g. of data or controls

Abstract

Systems and methods for battery management are disclosed. A system may include an internal control network including multiple node controllers powered by a unique cell or combination of cells of a battery. The node controllers may communicate with each other via a node communication system. Each node controller may be responsible for managing a charge level associated with one or more cells. The one or more devices of the internal control network may enable measurement of environmental factors such as a temperature and a current and voltage applied at the battery. Based on the measured environmental factors, the internal control network may perform an ongoing assessment of the one or more cells of the battery and of an overall battery condition. The internal control network may initiate turning on or off a battery output to prevent over discharge and possible damage to the battery or devices connected to the battery.

Claims

1. A battery management system comprising:

a plurality of cells coupled in series between a positive terminal and a negative terminal;

a first node controller electrically coupled to a first set of node subsystems, the first node controller powered by a first cell or set of cells of the plurality of cells; and

a second node controller electrically coupled to a second set of node subsystems, the second node controller powered by a second cell or set of cells of the plurality of cells, wherein the second set of cells differs from the first set of cells.

2. The system of claim 1, further comprising a first set of node subsystems communicatively coupled to the first node controller and a second set of node subsystems communicatively coupled to the second node controller.

3. The system of claim 2, wherein the first set of node subsystems comprises a first cell balancing subsystem and wherein the second set of node subsystems comprises a second cell balancing subsystem.

4. The system of claim 3, wherein the first set of cells comprises a first cell and a second cell, wherein the first cell balancing subsystem comprises:

a first resistor, a first terminal of the first resistor coupled to a first output of the first node controller and a second terminal of the first resistor coupled to a positive terminal of the second cell and to a negative terminal of the first cell; and

a second resistor, a first terminal of the second resistor coupled to a second output of the first node controller, and a second terminal of the second resistor coupled to a negative terminal of the second cell.

5. The system of claim 4, wherein the first node controller is configured to:

selectively couple a positive terminal of the first cell or the negative terminal of the second cell to the negative terminal of the first cell and the positive terminal of the second cell via the first resistor; and

selectively couple the positive terminal of the first cell to the negative terminal of the second cell via the second resistor.

6. The system of claim 3, wherein the second set of cells comprises a first cell and a second cell, wherein the second cell balancing subsystem comprises:

a first resistor, a first terminal of the first resistor coupled to a first output of the first node controller and a second terminal of the first resistor coupled to a positive terminal of the second cell and to a negative terminal of the first cell; and

a second resistor, a first terminal of the second resistor coupled to a second output of the first node controller, and a second terminal of the second resistor coupled to a negative terminal of the second cell.

7. The system of claim 1, further comprising an output control circuit positioned in series with the one or more cells between the positive terminal and the negative terminal, the output control circuit further coupled to the first node controller, the second node controller, or both.

8. The system of claim 7, wherein the output control circuit comprises a transistor positioned in series with the one or more cells, wherein a control input of the transistor is coupled to the first control node or to the second control node.

9. The system of claim 8, wherein the first node controller or the second node controller is configured to:

selectively apply a signal to the control input to enable the transistor when the plurality of cells are not charging; and

selectively refrain from applying the signal to the control input when the plurality of cells are charging.

10. The system of claim 9, wherein a voltage difference between the first terminal and the second terminal includes a diode voltage due to an intrinsic body diode of the transistor or a parallel diode when the transistor is enabled, and wherein the voltage difference between the first terminal and the second terminal does not include the diode voltage when the transistor is disabled.

11. The system of claim 9, wherein a voltage difference between the first terminal and the second terminal corresponds to a charging profile of a first type of battery when the transistor is enabled and to a charging profile of a second type of battery when the transistor is disabled.

12. The system of claim 11, wherein the first type of battery is a lead acid type battery and wherein the second type of battery is a lithium iron phosphate type battery.

13. The system of claim 1, further comprising a node communication system communicatively coupling the first node controller to the second node controller.

14. A battery management method for charging a first type of battery at a charger configured for a second type of battery, the method comprising:

calculating a battery charge level;

determining based on the battery charge level whether a charging input is to be decreased, wherein the charging input comprises an externally applied voltage difference between the first terminal and the second terminal; and

in response to determining that the charging input is to be decreased, triggering a decrease in the charging input.

15. The method of claim 14, wherein the battery charge level is based on voltages associated with one or more cells of the battery, on currents associated with the one or more cells, on a voltage difference between a first terminal and a second terminal of the battery, on an electrical current between the first terminal and the second terminal, on a temperature of the battery, on a charge profile history stored at the battery, or a combination thereof.

16. The method of claim 14, wherein triggering an increase in the charging input comprises increasing a voltage difference between the first terminal and the second terminal by applying a voltage to an input of a transistor coupled between the first terminal and the second terminal, wherein applying the voltage to the input increases a resistance of the transistor.

17. The method of claim 14, wherein triggering a decrease in the charging input comprises decreasing a voltage difference between the first terminal and the second terminal by lowering a voltage to an input of a transistor coupled between the first terminal and the second terminal or refraining from applying a voltage to the input of the transistor, wherein the transistor includes a parallel diode or an intrinsic body diode that causes a voltage drop across the diode when the transistor is disabled.

25. The system of claim 14, wherein the second node controller is configured to send data to the first node controller indicating a charge level of the second set of cells.

18. A battery management system for charge balancing, the system comprising:

a first node controller, the first node controller corresponding to a first cell or set of cells of a plurality of cells;

a second node controller, the second node controller corresponding to a second cell or set of cells of the plurality of cells, wherein the second set of cells differs from the first set of cells; and

a node communication system communicatively coupling the first node controller to the second node controller via a communication signal line.

19. The system of claim 18, wherein the communication signal line includes a capacitor positioned between the first node controller and the second node controller

20. The system of claim 19, wherein the communication signal line couples a signal input/output of the first node controller to a signal input/output of the second node controller via the capacitor.

21. The system of claim 18, further comprising another communication signal line that includes another capacitor, wherein the communication signal line couples an output of the first node controller to an input of the second node controller and the other communication signal line couples an output of the second node controller to an input of the first node controller.

22. The system of claim 18, wherein the first node controller comprises a first weak pull up resistor pulling an input signal at the first node controller to a high value, and wherein the second node controller comprises a second weak pull up resistor pulling an input signal at the second node controller to a high value.

23. The system of claim 22, wherein the first node controller selectively communicates with the second node controller by changing the input signal at the second node controller to a low value and the second node controller selectively communicates with the first node controller by changing the input signal at the first node controller to a low value.

24. The system of claim 18, wherein the first node controller is configured to send data to the second node controller indicating a charge level of the first set of cells.

26. The system of claim 18, wherein the first node and the second node are configured to balance the plurality of cells by discharging one or more cells through one or more resistors.

27. The system of claim 26, wherein the one or more resistors include at least one heating element configured to heat the plurality of cells in response to a current passing through the heating element.

28. A battery management method for cell balancing, the method comprising:

initiating measurement, by a first node controller, of first charge levels associated with each cell of a first set of cells of a battery, the first set of cells coupled to the first node controller, wherein a first total charge level associated with the first set of cells is based on the first charge levels;

in response to determining that the first charge levels are unbalanced, reducing a charge level of one or more cells of the first set of cells;

receiving, at the first node controller, an indication from a second node controller of a second total charge level associated with a second set of cells coupled to the second node controller; and

in response to determining that the first total charge level is not balanced with the second total charge level, simultaneously reducing a charge level of each cell of the first set of cells.

29. The method of claim 28, further comprising:

initiating measurement, at the second node controller, of second charge levels associated with each cell of the second set of cells coupled to the second node, wherein the second total charge level is based on the second charge levels;

in response to determining that the second charge levels are unbalanced, reducing a charge level of one or more cells of the second set of cells; and

sending, to the first node, the indication of the second total charge level.

30. The method of claim 28, wherein receiving an indication from the second node of the second total charge level comprises:

floating a first input/output (I/O) pin of the first node to a logical high value using a pull up resistor, wherein the first I/O pin is coupled to a second I/O pin of the second node; and

detecting, at the first node, that the first I/O pin is pulled to a logical low value.

31. The method of claim 30, wherein the first I/O pin is coupled to the second I/O pin via a capacitor.

32. The method of claim 28, wherein cell balancing is performed in response to a determination that a voltage of the battery corresponds to at least 50% charged while the battery is receiving a charging input.

33. The method of claim 28, wherein reducing the charge level of the one or more cells of the first set of cells comprises electrically connecting the one or more cells of the first set of cells to a first resistor, and wherein simultaneously reducing the charge level of each cell of the first set of cells comprises electrically connecting each cell of the first set of cells in series with a second resistor.

34. The method of claim 33, wherein electrically connecting the one or more of the cells of the first set of cells to the first resistor is performed via a first push-pull output of the first node controller, and wherein electrically connecting each cell of the first set of cells in series with a second resistor is performed via a second push-pull output of the first node controller.

35. The method of claim 33, wherein electrically connecting the one or more of the cells of the first set of cells to the first resistor is performed via a first network of transistors coupled to a first output of the first node controller, and wherein electrically connecting each cell of the first set of cells in series with a second resistor is performed via a second network of transistors coupled to a second output of the first node controller.

36. The method of claim 33, wherein the first resistor, the second resistor, or both are heating elements coupled to one or more cell of the first set of cells and the second set of cells.

37. A battery management system comprising:

a plurality of cells coupled in series between a positive terminal and a negative terminal; and

a transistor coupled in series with the plurality of cells between the positive terminal and the negative terminal.

38. The system of claim 37, further comprising a node controller configured to:

selectively enable or disable the transistor by sending a signal to a control input of the transistor; and

control a resistance of the transistor when the transistor is enabled.

39. The system of claim 37, further comprising a low current output circuit comprising:

a second transistor positioned in series with the plurality of cells and a resistor.

40. The system of claim 39, further comprising a node controller configured to:

selectively enable or disable the second transistor by sending a signal to a control input of the second transistor.

41. The system of claim 39, wherein a resistance of the resistor is sufficiently high to limit a current through the plurality of cells to less than or equal to 30 mA.

42. A battery management method for enabling low current output comprising:

disabling a first transistor positioned in series with a plurality of cells between a first terminal and a second terminal; and

enabling a second transistor positioned in series with the plurality of cells and in series with a resistor between a first terminal and a second terminal.

43. The method of claim 42, further comprising:

measuring load conditions corresponding to the plurality of cells; and

determining whether a load is present between the first terminal and the second terminal; and

in response to determining that a load is present between the first terminal and the second terminal, enabling the first transistor.

44. A battery management method for communicating with an external device, the method comprising:

when a battery is in a charging state, selectively enabling and disabling a transistor positioned in series with one or more cells between terminals of the battery, wherein selectively enabling and disabling the transistor changes a voltage between the terminals;

when the battery is in a state of discharge or in a quiescent state, selectively applying a voltage level to a control input of the transistor to change a resistance of the transistor, wherein changing a resistance of the transistor changes the voltage between the terminals.

45. The method of claim 44, further comprising modulating the voltage between the terminals to generate a signal to be received by a charging device coupled to the terminals.

46. The method of claim 45, wherein the signal includes data to be displayed to a user.

47. The method of claim 45, wherein the signal includes data to control charge input from the charging device.

48. The method of claim 45, wherein selectively enabling and disabling the transistor and selectively applying a voltage level to the control input is performed by a first node controller, the method further comprising:

receiving data at the first node controller from a second node controller; and

transmitting the data to the charging device via the signal.

49. The method of claim 48, wherein the data includes a temperature, a voltage between the terminals, a current through the one or more cells, a previous battery history, a previous charging level, a previous demand level, or combinations thereof.

50. The method of claim 44, further comprising receiving a signal from a charging device at a node controller.

51. The method of claim 50, wherein the signal includes a command received from a user.

52. The method of claim 50, wherein receiving the signals from the charging device comprises:

when the battery is in a charging state, initiating measurement of a current through the one or more cells; and

when the batter is in a state of discharge or in a quiescent state, initiating measurement of a voltage between terminals of the battery.

53. A battery management method for adapting a charging input, the method comprising:

receiving a charging input associated with a first battery chemistry-type, wherein the charging input comprises an externally applied current between the first terminal and the second terminal;

generating a modified charging input associated with a second battery chemistry-type corresponding to the plurality of cells, wherein the modified charging input comprises a current applied to the plurality of cells.

54. The method of claim 53, wherein generating the modified charging input comprises using one or more transistors positioned between the first terminal and the second terminal as a programmable resistor.

55. The method of claim 53, wherein an upper limit of a charge voltage level of the first battery chemistry-type is different than an upper limit of a charge voltage level of the second battery chemistry-type, and wherein a lower limit of the charge voltage level of the first battery chemistry-type is different than a lower limit of the charge voltage level of the second battery chemistry-type.

56. The method of claim 53, wherein the first battery chemistry-type includes lead-based (Pb-based) batteries, and wherein the second battery chemistry-type includes lithium-based (LiFePO4-based) batteries.

57. The method of claim 53, further comprising indicating a modified charge level to a charging device via a voltage difference between the first terminal and the second terminal, wherein the modified charge level is different than a total charge level associated with the plurality of cells.

58. The method of claim 57, wherein indicating the modified charge level comprises selectively refraining from applying a signal to a control input of a transistor positioned between the first terminal and the second terminal, wherein the transistor exhibits a diode-like voltage drop when disabled.

59. The method of claim 58, wherein the voltage drop is approximately 0.7 volts.

60. A battery management method of controlling an output of a battery, the method comprising:

measuring a voltage between terminals of a battery; and

disabling an output current of the terminals when the voltage is below a threshold voltage.

61. The method of claim 60, further comprising:

measuring the output current over a period of time; and

disabling the output current when the output current exceeds a threshold over the period of time.

62. The method of claim 60, further comprising:

evaluating an output current to determine a range of current demand and to determine a time of low current demand; and

disabling the output current at the time of low current demand.

63. The method of claim 60, wherein the battery receives a charging input via the terminals to charge one or more cells of the battery while the output current is disabled.

64. The method of claim 60, further comprising:

inhibiting current in a first direction between the terminals while the output current is disabled; and

enabling current in a second direction between the terminals while the output current is disabled.