Electrical system for motor vehicles

• US 6,304,054 B1
• Filed: 08/23/1999
• Issued: 10/16/2001
• Est. Priority Date: 09/02/1998
• Status: Expired due to Fees

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Blomberg, Bengt, Granberg, Anders
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/378,892
• Time in Patent Office: 785 Days
• Field of Search: 307/10.1, 320/104, 320/103, 320/121, 320/138, 322/37
• US Class Current: 320/104
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An electrical system (1) for motor vehicles, with a generator (6) and with double batteries (3,7), one of them a starting battery (3) and the other a consumer battery (7), has a charging regulator (9) between the generator and the starting battery. The charging regulator (9) is arranged between the batteries (3,7) and separates them and can regulate the magnitude of the charging current to the starting battery (3).

Claims

1. An electrical system for motor vehicles having a plurality of consumers, comprising:

a starter motor;

a generator;

a pair of batteries, one battery being a starting battery connected to the starter motor and the other battery being a consumer battery connected to the consumers; and

a charging regulator connected between the generator and the starting battery, the charging regulator being arranged between the pair of batteries to keep them separated from one another and to regulate the magnitude of the charging current to the starting battery, the charging regulator including first and second transistors and an electronic controller for controlling the first and second transistors, the first transistor being connected to the generator and the second transistor being connected to the starting battery, the electronic controller regulating the current to the starting battery from the generator by slowly turning on the second transistor when the generator begins to charge the starting battery and turning off the second transistor when the current has decreased to a predetermined value corresponding to the starting battery being fully charged.

2. An electrical system according to claim 1, wherein the first and second transistors are MOSFET transistors which are arranged in series between the generator and the starting battery and which have their D-electrodes connected together.

3. An electrical system according to claim 1, wherein the electronic controller turns on the first transistor by applying an analog or a digital signal thereto when the generator charges the starting battery.

4. An electrical system according to claim 1, further including a measuring device for measuring the charging current to the starting battery, the measuring device being connected to the electronic controller.

5. An electrical system according to claim 2, wherein the charging regulator is provided with an output to an engine control unit and is arranged to deliver current from whichever of the batteries has the higher voltage, the engine control unit being connected to the mutually connected D-electrodes.

6. An electrical system according to claim 5, wherein respective protective diodes are incorporated in each of the first and second transistors.