Vehicular power supply device

• US 6,639,384 B2
• Filed: 04/02/2002
• Issued: 10/28/2003
• Est. Priority Date: 04/03/2001
• Status: Active Grant

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Hasegawa, Tetsuya, Tamai, Yasuhiro
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/112,765
• Publication Number:
  US 20020140397A1
• Time in Patent Office: 574 Days
• Field of Search: 320/116, 320/118, 320/119, 320/120, 320/126, 320/127, 320/128, 320/137, 320/162, 320/163, 320/164
• US Class Current: 320/126
• CPC Class Codes: H02J 7/1423 with multiple batteries

Abstract

A vehicular power supply device which includes a generator, a high-voltage battery, a voltage converter, and a plurality of low-voltage batteries. The high-voltage battery is charged with power outputted from the generator and supplies the charged power to a high-voltage load. The voltage converter converts an output voltage of the high-voltage battery into another voltage. The plurality of low-voltage batteries respectively connected to the voltage converter in parallel, are charged with power outputted from the voltage converter and supply the charged power to a low-voltage load.

Claims

1. A vehicular power supply device, comprising:

a generator generating power;

a high-voltage battery being charged with power outputted from the generator, the high-voltage battery supplying the charged power to a high-voltage load;

a voltage converter converting an output voltage of the high-voltage battery into another voltage; and

a plurality of low-voltage batteries respectively being connected to the voltage converter in parallel and being charged with power outputted from the voltage converter, the low-voltage battery supplying the charged power to a low-voltage load.

2. The vehicular power supply device according to claim 1, further comprising:

a control circuit selecting at least one low-voltage battery for supplying the power required for driving the low-voltage load among the plurality of low-voltage batteries.

3. The vehicular power supply device according to claim 2, wherein the control circuit allows the plurality of low-voltage batteries to be sequentially charged with the power outputted from the voltage converter.

4. The vehicular power supply device according to claim 3, further comprising:

a detector for detecting a charge amount of the low-voltage battery, wherein, when the power required for driving the low-voltage load is smaller than a predetermined value, the control circuit allows a low-voltage battery having a small charge amount detected by the detector to be used for supplying the power prior to the other low-voltage batteries.

5. The vehicular power supply device according to claim 4, wherein the detector is configured with a current sensor for detecting a charge/discharge current of the low-voltage battery and a voltage sensor for detecting a voltage of a terminal thereof, the current and the voltage detected by the detector are sent to the control circuit, the control circuit calculates the charge amount based on the charge/discharge current and stores the calculated charge amount.

6. The vehicular power supply device according to claim 2, further comprising:

a box for accommodating the voltage converter and the control circuit.

7. The vehicular power supply device according to claim 2, further comprising:

a box for accommodating the control circuit wherein the voltage converter is provided outside of the box.