Vehicle battery charging system

• US 4,345,197 A
• Filed: 03/03/1980
• Issued: 08/17/1982
• Est. Priority Date: 03/03/1980
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Wheadon, Ellis G., Nowakowski, Robert J.
• Primary Examiner(s): HICKEY, ROBERT
• Application Number:
  US06/126,532
• Time in Patent Office: 897 Days
• Field of Search: 320/6-8, 320/15, 320/61, 322/25, 322/28, 322/35
• US Class Current: 320/124
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/1446 in response to parameters of a vehicle
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

The output voltage of an engine-driven generator is varied in accordance with engine vacuum in a manner to increase the charging rate during deceleration of the vehicle and to decrease the charging rate during acceleration of the vehicle. The charging current developed in the generator is alternately applied to one or the other of two storage batteries while the other storage battery is connected to supply power to the various electrical loads of the vehicle. A switching circuit responsive to the terminal voltage of the battery connected to supply power to the loads operates to exchange the battery connections when the voltage supplied to the loads decreases below a reference value so that the depleted battery is connected to be charged by the generator and the charged battery is connected to supply power to the loads.

Claims

1. A vehicular battery charging system comprising:

first and second storage batteries for supplying power to vehicular electrical loads;

a source of charging current;

a bistable switching means for alternatively connecting said storage batteries for charging and discharging, said bistable switching means having a first state wherein said first storage battery is connected to supply power to said electrical loads and said source of charging current is connected to charge said second storage battery, and a second state wherein said second storage battery is connected to supply power to said electrical loads and said source of charging current is connected to charge said first storage battery; and

means including voltage sensitive elements connected to each of said storage batteries responsive to the voltage of the storage battery that is connected to supply power to said electrical loads for changing the state of said bistable switching means when the voltage of such battery decreases below a reference valve which is independent of the instantaneous terminal voltage of either of said batteries, whereby the voltage supplied to said electrical loads is maintained within a range defined by the nominal terminal voltage of said storage batteries and said reference value.

2. A charge/discharge control system for the storage batteries of a vehicle comprising:

first and second storage batteries for supplying power to electrical loads of said vehicle;

a source charging current connected in a manner to charge each of said first and second storage batteries;

means for connecting said first storage battery to supply power to said electrical loads;

first switching means actuable to disconnect said source of charging current from said first storage battery when the terminal voltage of said first storage battery exceeds a reference value which is independent of the instantaneous terminal voltage of either of said batteries;

second switching means actuable to disconnect said source of charging current from said second storage battery, to connect said second storage battery to supply power to said electrical loads, and to disconnect said first storage battery from said electrical loads when the terminal voltage of said second storage battery exceeds said reference value; and

means responsive to the actuation of said first and second switching means to prevent actuation of the other of said switching means, said first and second switching means thereby forming a bistable switching device wherein said first or second switching means are alternately actuated according to the terminal voltage of the battery connected to supply power to said electrical loads, whereby said first and second storage batteries are alternately connected to said source of charging current or said electrical loads to maintain the voltage supplied to said electrical loads at a value between the reference value and the nominal terminal voltage of said first and second storage batteries.

3. A battery charging system comprising:

first and second storage batteries for supplying power to vehicular electrical loads;

an engine-driven source of voltage for charging said storage batteries, and means for controlling the voltage of said source over a wide range as a function of the load of said engine;

switching means for alternately connecting said storage batteries for charging and discharging, said switching means having a first stage wherein said first storage battery is connected to supply power to said electrical loads and said source of voltage is connected to charge said second storage battery, and a second state wherein said second storage battery is connected to supply power to said electrical loads and said source of voltage is connected to charge said first storage battery;

means responsive to the terminal voltage of the storage battery connected to supply power to said electrical loads for changing the state of said switching means when said terminal voltage decreases below a reference value whereby the voltage supplied to said electrical loads is maintained within a narrow range defined by the nominal terminal voltage of said storage batteries and said reference value despite the wide range of charging voltage developed by said source of voltage.

4. A battery charging system comprising:

first and second storage batteries for supplying power to vehicular electrical loads;

an engine-driven source of voltage for charging said storage batteries, and means for controlling the voltage of said source of voltage over a wide range as a function of the internal vacuum of said engine;

switching means for alternately connecting said storage batteries for charging and discharging, said switching means having a first state wherein said first storage battery is connected to supply power to said electrical loads and said source of voltage is connected to charge said second storage battery, and a second state wherein said second storage battery is connected to supply power to said electrical loads and said source of voltage is connected to charge said first storage battery;

means responsive to the terminal voltage of the storage battery connected to supply power to said electrical loads for changing the state of said switching means when said terminal voltage decreases below a reference value whereby the voltage supplied to said electrical loads is maintained within a narrow range defined by the nominal terminal voltage of said storage batteries and said reference value despite the wide range of charging voltage developed by said source of voltage.

5. A charge/discharge control system for the storage batteries of a vehicle comprising:

first and second storage batteries for supplying power to electrical loads of said vehicle;

an engine-driven source of direct current;

switch means having a rest position wherein said source of direct current is connected to charge said first and second storage batteries, and said first storage battery is connected to supply power to said electrical loads;

first electrically actuable means for disconnecting said source of direct current from said first storage battery when (1) said engine is operational and (2) the terminal voltage of said first storage battery exceeds a reference value;

second electrically actuable means for disconnecting said source of direct current from said second storage battery, for connecting said second storage battery to supply power to said electrical loads, and for disconnecting said first storage battery from said electrical loads when (1) said engine is operational and (2) the terminal voltage of said second storage battery exceeds said reference value;

means resposive to the actuation of said first and second electrically actuable means to prevent actuation of the other of said electrically actuable means; and

non-electrical means for returning said switch means to said rest position when said engine is not operational or in the event of an electrical power failure, whereby said first and second storage batteries are connected to be charged by said source of direct current and said first storage battery is connected to supply power to said electrical loads despite an electrical failure that prevents actuation of said first and second electrically actuable means.

6. A vehicular battery charging system comprising:

first and second storage batteries for supplying power to vehicular electrical loads;

a source of charging current;

bistable storage battery connection means switchable between a first state wherein said first storage battery is connected to supply power to said electrical loads and said source of charging current is connected to charge said second storage battery, and a second state wherein said second storage battery is connected to supply power to said electrical loads and said source of charging current is connected to charge to said first storage battery; and

means responsive to the terminal voltages of said first and second storage batteries for switching the state of said bistable battery connection means when the terminal voltage of the battery connected to supply power to said electrical loads falls below a reference value, the terminal voltage of the storage battery connected to said source of charging current being ineffective for switching the state of said bistable battery connection means so long as such voltage exceeds said reference value, whereby the voltage supplied to said electrical loads is maintained within a range defined by the nominal terminal voltage of said batteries and said reference value.