Power supply control system for vehicle and method

• US 7,042,115 B2
• Filed: 02/14/2003
• Issued: 05/09/2006
• Est. Priority Date: 02/26/2002
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Mizutani, Koichi, Abo, Shouji, Ohtsuka, Kan
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US10/366,380
• Publication Number:
  US 20030160510A1
• Time in Patent Office: 1,180 Days
• Field of Search: 307/80, 307/9.1, 307/10.6, 320/103, 320/104
• US Class Current: 307/10.1
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 11/087 Details of the switching means in starting circuits, e.g. relays or electronic switches
• CPC Class Codes: F02N 11/14 Starting of engines by means of electric starters with external current supply F02N11/12 takes precedence
• CPC Class Codes: F02N 2011/0888 DC/DC converters
• CPC Class Codes: F02N 2300/2002 using different starting modes, methods, or actuators depending on circumstances, e.g. engine temperature or component wear
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A power supply control system for a vehicle that is provided with a lead-acid battery with comparatively high output density and low energy density, and a lithium-ion battery with comparatively low output density and high energy density. On an engine start that accompanies an ignition operation of a vehicle operator, power is supplied to a starter from the lead-acid battery and the engine is started. On an engine restart that accompanies an idling stop control, power is supplied to the starter from the lithium-ion battery and the engine is started.

Claims

1. A power supply control system for a vehicle in which an idling stop control is performed such that an engine is automatically stopped and started in accordance with an operating state of the vehicle, the power supply control system comprising:

a first battery connected to a starter of the vehicle;

a second battery connected to the starter of the vehicle, and having an energy density higher than that of the first battery and having an output density lower than that of the first battery; and

a controller operative to select the first battery to be connected to the starter so as to receive a power supply from the first battery under a first condition where the engine is started to cause the vehicle to take off, and to select the second battery to be connected to the starter so as to receive the power supply from the second battery under a second condition where the engine is started by the idling stop control.

2. The power supply control system according to claim 1, wherein the second battery comprises one of a lithium-ion battery and a nickel metal hydride battery.

3. The power supply control system according to claim 1, wherein the first battery comprises a lead-acid battery.

4. The power supply control system according to claim 2, wherein the first battery comprises a lead-acid battery.

5. The power supply control system according to claim 1, wherein the start of the engine under the first condition is established on the basis of an intention of a vehicle operator of causing the vehicle to take off.

6. The power supply control system according to claim 1, wherein the start of the engine under the first condition is established upon authentication of a wireless communication between a device mounted on the vehicle and a portable device carried by the vehicle operator.

7. The power supply control system according to claim 1, wherein the controller determines whether the power supply to the starter from the second battery is sufficient to start the engine;

and when it is determined that the power supply to the starter from the second battery to start the engine under the second condition is insufficient, selects the first battery to be connected to the starter so as to receive the power supply from the first battery.

8. The power supply control system according to claim 1, wherein the controller determines whether the power supply to the starter from the first battery is sufficient to start the engine;

and when it is determined that the power supply to the starter from the first battery to start the engine under the first condition is insufficient, selects the second battery to be connected to the starter so as to receive the power supply from the second battery.

9. The power supply control system according to claim 7, wherein the controller determines whether the power supply to the starter from the first battery is sufficient to start the engine;

and when it is determined that the power supply to the starter from the first battery to start the engine under the first condition is insufficient, selects the second battery to be connected to the starter so as to receive the power supply from the second battery.

10. The power supply control system according to claim 9, wherein the controller determines each power supply sufficiency to the starter of the first battery and the second battery on the basis of one of parameters including a capacity, a temperature, a voltage, and a current of each of the first battery and the second battery.

11. The power supply control system according to claim 1, wherein the start of the engine under the second condition is canceled when at least one of a voltage and a capacity of each of the first battery and the second battery is smaller than a predetermined value.

12. A power supply control method for a vehicle in which an idling stop control is performed such that an engine is automatically stopped and started in accordance with an operating state of the vehicle, and a first battery and a second battery having a higher energy density and a lower output density than the first battery are connected to a starter, the power supply control method comprising:

selecting the first battery to be connected to the starter so as to receive a power supply from the first battery under a first condition where the engine is started to cause the vehicle to take off; and

selecting the second battery to be connected to the starter so as to receive the power supply from the second battery under a second condition where the engine is started by the idling stop control.

13. The power supply control method according to claim 12, wherein the start of the engine under the first condition is established on the basis of an intention of a vehicle operator of causing the vehicle to take off.

14. The power supply control method according to claim 12, wherein the start of the engine under the first condition is established upon authentication of a wireless communication between a device mounted on the vehicle and a portable device carried by the vehicle operator.

15. The power supply control method according to claim 12, further comprising determining whether the power supply to the starter from the second battery is sufficient to start the engine;

and selecting the first battery to be connected to the starter so as to receive the power supply from the first battery when it is determined that the power supply to the starter from the second battery to start the engine under the second condition is insufficient.

16. The power supply control method according to claim 12, further comprising determining whether the power supply to the starter from the first battery is sufficient to start the engine;

and selecting the second battery to be connected to the starter so as to receive the power supply from the second battery when it is determined that the power supply to the starter from the first battery to start the engine under the first condition is insufficient.

17. The power supply control method according to claim 15, further comprising determining whether the power supply to the starter from the first battery is sufficient to start the engine;

and selecting the second battery to be connected to the starter so as to receive the power supply from the second battery when it is determined that the power supply to the starter from the first battery is insufficient.

18. The power supply control method according to claim 17, wherein each power supply sufficiency to the starter of the first battery and the second battery is determined on the basis of one of parameters including a capacity, a temperature, a voltage, and a current of the one of the first battery and the second battery.

19. The power supply control method according to claim 12, further comprising canceling the start of the engine under the second condition when at least one of a voltage and a capacity of each of the first battery and the second battery is smaller than a predetermined value.