Split charge battery start assist

Patent metadata

Field	Value
Publication number	US-11549477-B1
Application number	US-202217816162-A
Country	US
Kind code	B1
Filing date	Jul 29, 2022
Priority date	Jul 29, 2022
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

An electrical system of a vehicle includes a first battery, a second battery, a first switch electrically connected in series between the first battery and the second battery, an external connection point, and a second switch electrically connected in series between the second battery and the external connection point. The system and a method of operating the system include determining that the first battery will need assistance to start an engine of the vehicle, opening the second switch in response to a state of charge of the second battery decreasing below a charge threshold, and closing the first switch for the second battery to assist the first battery to crank the engine for starting.

First claim

The invention claimed is:

1. An electrical system of a vehicle comprising:
a first battery;
a second battery;
a first switch electrically connected in series between the first battery and the second battery;
an external connection point;
a second switch electrically connected in series between the second battery and the external connection point; and
a computer communicatively coupled to the first switch and the second switch, the computer programmed with computer executable instructions to:
determine that the first battery will need assistance to start an engine of the vehicle;
instruct the second switch to open in response to a state of charge of the second battery decreasing below a charge threshold; and
instruct the first switch to close for the second battery to assist the first battery to crank the engine for starting.

2. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance determines that a state of charge of the first battery is less than 50%;
the instructions executable to instruct the second switch to open is in response to the state of charge of the second battery decreasing below 60%; and
the instructions executable to instruct the first switch to close is performed before beginning to crank the engine.

3. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance determines that a health of the first battery is weak;
the instructions executable to instruct the second switch to open is in response to the state of charge of the second battery decreasing below 70%; and
the instructions executable to instruct the first switch to close is performed before beginning to crank the engine.

4. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance determines that an age of the first battery has exceeded a threshold age;
the instructions executable to instruct the second switch to open is in response to the state of charge of the second battery decreasing below 70%; and
the instructions executable to instruct the first switch to close is performed before beginning to crank the engine.

5. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance determines that an outside ambient temperature is or is predicted to be below 0*C in a location of the vehicle within a next 24 hours;
the instructions executable to instruct the second switch to open is in response to the state of charge of the second battery decreasing below 70%; and
the instructions executable to instruct the first switch to close is performed before beginning to crank the engine.

6. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance determines that a cranking speed during a first crank of a day is decreasing over a period of a last three starts;
the instructions executable to instruct the second switch to open is in response to the state of charge of the second battery decreasing below 70%; and
the instructions executable to instruct the first switch to close is performed before beginning to crank the engine.

7. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance determines that a state of charge of the first battery is below 40%; and
the instructions executable to instruct the first switch to close is performed during a key-off period and keep the first switch closed until the second battery has raised the state of charge of the first battery above 50%.

8. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance further includes instructions to determine that a voltage (V) of the first battery during cranking drops below 10 V; and
the instructions executable to instruct the first switch to close is performed during cranking.

9. The electrical system of claim 1 , wherein:
the instructions executable to determine that the first battery will need assistance further includes instructions to determine that a cranking speed in rotations per minute (RPM) during a cranking performed by the first battery is below 100 RPM; and
the instructions executable to instruct the first switch to close is performed during cranking.

10. The electrical system of claim 9 , further comprising instructions to:
send a notification that the first battery is performing poorly.

11. A method of operating an electrical system of a vehicle having a first battery, a second battery, a first switch electrically connected in series between the first battery and the second battery, an external connection point, and a second switch electrically connected in series between the second battery and the external connection point, the method comprising:
determining that the first battery will need assistance to start an engine of the vehicle;
opening the second switch in response to a state of charge of the second battery decreasing below a charge threshold; and
closing the first switch for the second battery to assist the first battery to crank the engine for starting.

12. The method of claim 11 , wherein:
determining that the first battery will need assistance includes determining that a state of charge of the first battery is less than 50%;
opening of the second switch is in response to the state of charge of the second battery decreasing below 60%; and
closing of the first switch is performed before beginning to crank the engine.

13. The method of claim 11 , wherein:
determining that the first battery will need assistance includes determining that a health of the first battery is weak;
opening of the second switch is in response to the state of charge of the second battery decreasing below 70%; and
closing of the first switch is performed before beginning to crank the engine.

14. The method of claim 11 , wherein:
determining that the first battery will need assistance includes determining that an age of the first battery has exceeded a threshold age;
opening of the second switch is in response to the state of charge of the second battery decreasing below 70%; and
closing of the first switch is performed before beginning to crank the engine.

15. The method of claim 11 , wherein:
determining that the first battery will need assistance includes determining that an outside ambient temperature is or is predicted to be below 0*C in a location of the vehicle within a next 24 hours;
opening of the second switch is in response to the state of charge of the second battery decreasing below 70%; and
closing of the first switch is performed before beginning to crank the engine.

16. The method of claim 11 , wherein:
determining that the first battery will need assistance includes determining that a cranking speed during a first crank of a day is decreasing over a period of a last three starts;
opening of the second switch is in response to the state of charge of the second battery decreasing below 70%; and
closing of the first switch is performed before beginning to crank the engine.

17. The method of claim 11 , wherein:
determining that the first battery will need assistance includes determining that a state of charge of the first battery is below 40%; and
closing of the first switch is performed during a key-off period and keep the first switch closed until the second bat

Assignees

• Ford Global Tech Llc

Inventors

• Salter Stuart C
• Collins Alasdair
• Celinske David
• Spoto Anthony Thomas
• Ansbacher Todd

Classifications

• F02N2200/061

  Battery state of charge [SOC] · CPC title

• F02N2200/041

  Starter speed · CPC title

• H01M10/482

  for several batteries or cells simultaneously or sequentially · CPC title

• F02N11/087 Primary

  Details of the switching means in starting circuits, e.g. relays or electronic switches · CPC title

• F02N2011/0874

  characterised by said switch being an electronic switch · CPC title