Dual voltage battery system for a vehicle

Patent metadata

Field	Value
Publication number	US-11215156-B2
Application number	US-201815910663-A
Country	US
Kind code	B2
Filing date	Mar 2, 2018
Priority date	Mar 3, 2017
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A power management system for a vehicle includes a first battery monitoring module configured to monitor a first state of charge (SOC) of a first battery of the vehicle. The first battery has a first nominal voltage. A second battery monitoring module is configured to monitor a second SOC of a second battery of the vehicle. The second battery has a second nominal voltage that is greater than the first nominal voltage. A control module is configured to, using a direct current (DC) to DC converter, selectively charge the second battery with power from the first battery until the second SOC of the second battery is greater than or equal to a predetermined SOC.

First claim

What is claimed is:

1. A power management system for a vehicle, comprising:
a first battery monitoring module configured to monitor a first state of charge (SOC) of a first battery of the vehicle,
wherein the first battery has a first nominal voltage;
a second battery monitoring module configured to monitor a second SOC of a second battery of the vehicle,
wherein the second battery has a second nominal voltage that is greater than the first nominal voltage;
a control module configured to, using a direct current (DC) to DC converter, selectively charge the second battery with power from the first battery until the second SOC of the second battery is greater than or equal to a predetermined SOC; and
a starter control module configured to selectively apply power to a starter of an engine from the second battery.

2. The power management system of claim 1 wherein the control module is configured to selectively charge the second battery with power from the first battery when the second SOC of the second battery at shutdown of the engine of the vehicle is less than the predetermined SOC.

3. The power management system of claim 1 wherein the control module is configured to:
determine whether to charge the second battery with power from the first battery based on an ambient temperature at shutdown of the engine; and
selectively charge the second battery with power from the first battery based on the determination.

4. The power management system of claim 1 wherein the control module is further configured to, prior to a startup of the engine of the vehicle, selectively apply power to a heater of the second battery based on a temperature of the second battery and the SOC of the second battery.

5. The power management system of claim 4 wherein the control module is configured to, prior to the startup of the engine of the vehicle, apply power to the heater of the second battery when the temperature of the second battery is less than a predetermined temperature.

6. The power management system of claim 4 wherein the control module is configured to, prior to the startup of the engine of the vehicle, apply power to the heater of the second battery from the first battery when:
the temperature of the second battery is less than a predetermined temperature; and
the second SOC of the second battery is less than the predetermined SOC.

7. The power management system of claim 1 wherein the control module is further configured to, prior to a startup of the engine of the vehicle, using the DC to DC converter, charge the first battery with power from the second battery when the second SOC of the second battery is greater than a second predetermined SOC.

8. The power management system of claim 7 wherein the second predetermined SOC is greater than the predetermined SOC.

9. A power management system for a vehicle, comprising:
a first battery monitoring module configured to monitor a first state of charge (SOC) of a first battery of the vehicle,
wherein the first battery has a first nominal voltage;
a second battery monitoring module configured to monitor a second SOC of a second battery of the vehicle,
wherein the second battery has a second nominal voltage that is greater than the first nominal voltage;
a control module configured to, using a direct current (DC) to DC converter, selectively charge the second battery with power from the first battery until the second SOC of the second battery is greater than or equal to a predetermined SOC, wherein the control module is configured to:
in response to a shutdown of an engine of the vehicle, determine an estimated temperature at a next startup of the engine;
determine whether to charge the second battery with power from the first battery based on the estimated temperature; and
selectively charge the second battery with power from the first battery based on the determination.

10. The power management system of claim 9 wherein the control module is configured to set the estimated temperature at the next startup of the engine based on an ambient temperature at the shutdown of the engine.

11. The power management system of claim 10 wherein the control module is configured to set the estimated temperature at the next startup of the engine based on an ambient temperature obtained in response to the shutdown of the engine minus a predetermined temperature.

12. The power management system of claim 9 wherein the control module is configured to determine the estimated temperature at the next startup of the engine based on an average temperature at a location of the vehicle at the next startup of the engine.

13. The power management system of claim 9 wherein the control module is configured to determine the estimated temperature at the next startup of the engine based on a forecast temperature at a location of the vehicle at the next startup of the engine.

14. The power management system of claim 9 wherein the control module is configured to determine the estimated temperature at the next startup of the engine based on a plurality of previous temperatures at previous startups of the engine performed near a location of the vehicle, respectively.

15. The power management system of claim 9 wherein the control module is configured to determine to charge the second battery with power from the first battery when, based on the estimated temperature at the next startup of the engine, an estimated value of the second SOC of the second battery at the next startup of the engine is less than the predetermined SOC.

16. The power management system of claim 1 wherein the control module is configured to:
in response to a shutdown of the engine of the vehicle, determine an estimated temperature at a next startup of the engine;
determine an ambient temperature at the next startup of the engine; and
selectively apply power to a heater of the second battery based on a comparison of the estimated temperature at the next startup of the engine and the ambient temperature at the next startup of the engine.

17. The power management system of claim 16 wherein the control module is configured to selectively apply power from only the second battery to the heater when the estimated temperature at the next startup of the engine is greater than the ambient temperature at the next startup of the engine.

18. The power management system of claim 16 wherein the control module is configured to selectively apply power from both the first battery and the second battery to the heater when the estimated temperature at the next startup of the engine is less than the ambient temperature at the next startup of the engine.

19. A power management method for a vehicle, comprising:
monitoring a first state of charge (SOC) of a first battery of the vehicle,
wherein the first battery has a first nominal voltage;
monitoring a second SOC of a second battery of the vehicle,
wherein the second battery has a second nominal voltage that is greater than the first nominal voltage;
using a direct current (DC) to DC converter, selectively charging the second battery with power from the first battery until the second SOC of the second battery is greater than or equal to a predetermined SOC; and
selectively applying power to a starter of an engine from the second battery.

20. The power management method of claim 19 wherein the selectively charging the second battery includes selectively charging the second battery with power from the first battery when the second SOC of the second battery at shutdown of the engine of the

Assignees

• Gentherm Inc

Inventors

• Ciaccio Michael Peter
• Hughes Timothy

Classifications

• H02J2105/33

  exchanging power with road vehicles · CPC title

• H02J7/585

  Sequential battery discharge in systems with a plurality of batteries · CPC title

• H02J7/975

  in response to temperature · CPC title

• H02J7/855

  with circuits adapted for supplying loads from the battery · CPC title

• H02J7/96

  in response to battery voltage · CPC title