Method and apparatus for charging a high voltage battery of an automotive vehicle having a high voltage battery and a low voltage battery

• US 6,791,295 B1
• Filed: 02/20/2003
• Issued: 09/14/2004
• Est. Priority Date: 02/20/2003
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Berels, David Jeffeory
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/248,806
• Publication Number:
  US 20040164703A1
• Time in Patent Office: 572 Days
• Field of Search: 320/104, 320/149, 320/103, 320/132, 320/134, 320/150
• US Class Current: 320/103
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: H02J 1/082 Plural DC voltage, e.g. DC supply voltage with at least two different DC voltage levels
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

An electrical system for an automotive vehicle includes a low voltage battery having a low voltage, a high voltage battery having a high voltage, and a DC-to-DC converter coupled to the low voltage battery and the high voltage battery. A controller controls a conversion of the low voltage to a high voltage through the DC-to-DC converter and controls the charging of the high voltage battery with the high voltage. The controller monitors a state of charge of the high voltage battery, compares the state of charge to a predetermined state of charge and generates an indicator when the state of charge reaches the predetermined state of charge.

Claims

1. A method of charging a high voltage battery comprising:

electrically coupling a first low voltage source to a low voltage battery;

converting the low voltage to a high voltage;

charging a high voltage battery with the high voltage;

monitoring a state of charge of the high voltage battery;

comparing the state of charge to a predetermined state of charge; and

generating an indicator when the state of charge reaches the predetermined state of charge.

2. A method as recited in claim 1 wherein when monitoring a state of charge comprises measuring a battery voltage and measuring a battery current.

3. A method as recited in claim 1 further comprising coupling the low voltage battery to a high voltage battery through a contactor.

4. A method as recited in claim 3 further comprising comparing the low voltage battery voltage and the high voltage battery voltage and controlling the contactor in response to comparing.

5. A method as recited in claim 1 wherein converting comprises converting the low voltage to a high voltage using a DC-to-DC converter.

6. A method as recited in claim 1 wherein said predetermined state of charge corresponds to a starting state of charge to enable starting of the engine with a starter/generator.

7. A method as recited in claim 1 wherein generating an indicator comprises generating a visual indicator.

8. A method as recited in claim 1 wherein generating an indicator comprises generating an audible indicator.

9. A method as recited in claim 1 further comprising generating an initiating electrical signal from a switch coupled to a battery terminal.

10. A method as recited in claim 1 wherein the indicator indicates the high voltage battery is charged.

11. A method as recited in claim 1 further comprising generating a second indicator indicating the high voltage battery is not charged when the state of charge is less than the predetermined threshold.

12. A method of charging a high voltage battery through a first low voltage battery generating a low voltage with a low voltage source electrically coupled to the low voltage battery comprising:

converting the low voltage to a high voltage through a DC-to-DC converter;

charging a high voltage battery with the high voltage;

monitoring a state of charge of the battery;

comparing the state of charge to a predetermined state of charge;

generating a first indicator when the state of charge is below the predetermined state of charge; and

generating a second indicator when the state of charge reaches the predetermined state of charge.

13. A method as recited in claim 12 wherein when monitoring a state of charge comprises measuring a battery voltage and measuring a battery current.

14. A method as recited in claim 12 further comprising coupling the low voltage battery to a high voltage battery through a contactor.

15. A method as recited in claim 14 further comprising comparing the first battery voltage and the second battery voltage and controlling the contactor in response to comparing.

16. A system for an automotive vehicle comprising:

a low voltage battery having a low voltage;

a high voltage battery having a high voltage;

a DC-to-DC converter coupled between the low voltage battery and the high voltage battery; and

a controller coupled to the high voltage battery, the low voltage battery and said controller controlling a conversion of the low voltage to a high voltage through the DC-to-DC converter and controlling charging of the high voltage battery with the high voltage, said controller monitoring a state of charge of the high voltage battery, comparing the state of charge to a predetermined state of charge, said controller generating an indicator when the state of charge reaches the predetermined state of charge.

17. A system as recited in claim 16 further comprising a starter/generator and a starting load, wherein said predetermined state of charge being a function of said temperature and said starting load.

18. A system as recited in claim 16 further comprising a battery terminal cover coupled to a battery terminal of the low voltage battery.

19. A system as recited in claim 16 further comprising a battery terminal cover generating an electrical signal when the battery terminal cover is in an open position, said electrical signal coupled to said controller.

20. A hybrid electric vehicle having a system as recited in claim 16.