Low charge acceptance mitigation using a traction battery

• US 9,796,291 B1
• Filed: 11/09/2016
• Issued: 10/24/2017
• Est. Priority Date: 11/09/2016
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Symanow, David Anthony
• Primary Examiner(s): Lee, Tyler J
• Application Number:
  US15/347,088
• Time in Patent Office: 349 Days
• Field of Search: 701 22
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 16/00 Structural combinations of different types of electrochemical generators
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2220/00 Batteries for particular applications
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor

Abstract

A controller may include input channels configured to receive charge acceptance values of an auxiliary battery and an SOC of a traction battery. The controller may also include output channels configured to provide threshold signals to set a voltage threshold of an auxiliary bus coupled with the auxiliary battery and deriving power from the traction battery. The controller may include control logic configured to generate the threshold signals such that during a next charging event, a voltage of the auxiliary battery achieves a desulfation value. The controller logic may generate the threshold signals in response to the acceptance falling below a predetermined sulfation value and the SOC being above an SOC threshold.

Claims

1. A controller of a vehicle comprising:

input channels configured to receive a charge acceptance value (CAV) of an auxiliary battery and a state of charge (SOC) of a traction battery;

output channels configured to provide threshold signals to set a voltage threshold of an auxiliary bus coupled with the auxiliary battery and powered by the traction battery during a next charging event; and

control logic configured to, in response to the CAV falling below a predetermined sulfation value and the SOC being above an SOC threshold, generate the threshold signals such that a voltage of the auxiliary battery achieves a desulfation value during the event.

2. The controller of claim 1, wherein the control logic is further configured to, in response to the CAV exceeding the predetermined sulfation value during the event, generate the threshold signals such that the voltage of the auxiliary battery falls below the desulfation value.

3. The controller of claim 2, wherein the generating is further in response to a vehicle key-off event.

4. The controller of claim 3, wherein a temperature of the auxiliary battery during the key-off event is above a temperature threshold.

5. The controller of claim 3, wherein the control logic is further configured to adjust the CAV to be temperature independent.

6. The controller of claim 3, wherein the control logic is further configured to, in response to the CAV falling below a predetermined stratification value, generate the threshold signals such that during the event a voltage of the auxiliary battery achieves a destratification value, and in response to the CAV exceeding the predetermined stratification value during the event, generate the threshold signals such that the voltage of the auxiliary battery falls below the destratification value.

7. The controller of claim 3, wherein the auxiliary battery has a state of charge falling below a state of charge threshold after the key-off event.

8. The controller of claim 7, wherein the input channels are further configured to receive a traction battery state of charge during the next charging event, and the control logic is further configured to, in response to the traction battery state of charge decreasing by more than a predetermined stored energy loss threshold, generate output signals to discontinue charging of the auxiliary battery.

9. A method comprising:

generating voltage threshold signals such that during a next charging event, a voltage of an auxiliary battery achieves a stratification value in response to a charge acceptance value of the auxiliary battery falling below a predetermined stratification value; and

setting a voltage threshold of an auxiliary bus, coupled with the auxiliary battery and deriving power from a traction battery, provided a state of charge of the traction battery is above a threshold.

10. The method of claim 9, wherein the generating is further in response to a vehicle key-off event.

11. The method of claim 10, wherein a temperature of the auxiliary battery during the key-off event is above a temperature threshold.

12. The method of claim 10 further comprising adjusting the charge acceptance value to be temperature independent.

13. The method of claim 10 further comprising,

generating destratification voltage threshold signals in response to the charge acceptance value exceeding the predetermined stratification value during the event such that the voltage of the auxiliary battery falls below the stratification value;

generating desulfation voltage threshold signals such that during the next charging event, the voltage of the auxiliary battery achieves a desulfation value in response to the charge acceptance value falling below a desulfation value and being above a destratification value; and

lowering values associated with the voltage threshold signals such that the voltage of the auxiliary battery falls below the desulfation value in response to the charge acceptance value exceeding a predetermined sulfation value during the event.

14. The method of claim 10, wherein the auxiliary battery has a state of charge falling below a state of charge threshold after the key-off event.

15. The method of claim 14 further comprising,

receiving a traction battery state of charge during the next charging event, and

generating voltage threshold signals to discontinue charging of the auxiliary battery in response to the traction battery state of charge decreasing by more than a predetermined stored energy loss threshold.

16. A vehicle system comprising:

a controller having

input channels configured to receive a charge acceptance value (CAV) related to an auxiliary battery, and a state of charge (SOC) of a traction battery;

output channels configured to provide threshold signals to set a voltage threshold of an auxiliary bus coupled with the auxiliary battery and deriving power from the traction battery; and

control logic configured to,

in response to the CAV falling below a predetermined stratification value and the SOC being above an SOC threshold, generate the threshold signals such that during a next charging event, a voltage of the auxiliary battery achieves a stratification value,

in response to the CAV exceeding the predetermined stratification value during the event, generate the threshold signals such that the voltage of the auxiliary battery falls below the stratification value,

in response to the CAV falling below a predetermined sulfation value and being above the predetermined stratification value, generate the threshold signals such that during a next charging event a voltage of the auxiliary battery achieves a desulfation value, and

in response to the CAV exceeding the predetermined sulfation value during the event, generate the threshold signals such that the voltage of the auxiliary battery falls below the desulfation value.

17. The system of claim 16, wherein the setting is further in response to a vehicle key-off event.

18. The system of claim 17, wherein a temperature of the auxiliary battery during the key-off event is above a temperature threshold.

19. The system of claim 17, wherein the auxiliary battery has a state of charge falling below a state of charge threshold after the key-off event.

20. The system of claim 17, wherein the input channels are further configured to receive a traction battery state of charge during the next charging event, and the control logic is further configured to, in response to the traction battery state of charge decreasing by more than a predetermined stored energy loss threshold, generate output signals to discontinue charging of the auxiliary battery.