Battery protection system and method

• US 6,646,845 B1
• Filed: 09/21/2000
• Issued: 11/11/2003
• Est. Priority Date: 09/21/2000
• Status: Expired due to Term

• Current Assignee: Aptiv Technologies Limited (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Rajashekara, Kaushik, Formulak, Mark S., Turner, Steven Richard
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): Rodriguez, Isabel
• Application Number:
  US09/667,095
• Time in Patent Office: 1,146 Days
• Field of Search: 361/82, 361/92, 320/13, 320/40, 307/10.7
• US Class Current: 361/86
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045
• CPC Class Codes: H02J 9/002 in which a reserve is maintained in an energy source by disconnecting non-critical loads, e.g. maintaining a reserve of charge in a vehicle battery for starting an engine

Abstract

A battery protection system for a battery having a switching mechanism positioned intermediate to the positive terminal and an electrical load of the battery. A controller manipulates the switching mechanism between an open position and a closed position, the closed position connects the electrical load to the battery and the open position disconnects the electrical load from the battery. The battery protection system utilizes a battery state-of-charge detection system, which instructs the controller to open the switching mechanism when the detection system detects a battery state-of-charge that is lower than a threshold value. The battery protection system is also equipped with a vehicle status detection system, which instructs the controller to close the switching mechanism when a vehicle startup condition is detected by the vehicle status detection system.

Claims

1. A battery protection system for a battery, comprising:

an electronic switching device comprising a plurality of electronic switches positioned intermediate to a positive terminal of a battery and an electrical load;

a controller for manipulating said electronic switching device between an open circuit position and a closed circuit position, said closed circuit position connecting said electrical load to said battery and said open circuit position disconnecting said electrical load from said battery;

a detection system, said detection system instructs said controller to manipulate said electronic switching device into said open circuit position when said detection system detects a battery charge that is lower than a threshold value, said threshold value is a charge sufficient enough to provide cranking power to an automobile engine;

a short-circuit detection system being capable of detecting a short-circuit situation within said electrical load of said battery, said short-circuit detection system instructs said controller to manipulate said electronic switching device into said open circuit position when said short-circuit detection system detects said short-circuit;

a manual override switch for completely disconnecting said battery from any electrical load;

a bypass circuit being adapted to allow a bypass current to flow from the battery when said electronic switching device is in said open circuit position, said bypass current being incapable of supplying a starting voltage to an engine of a vehicle into which the battery is installed;

a vehicle status detection system, said vehicle status detection system instructs said controller to manipulate said electronic switching device into said closed circuit position when a battery re-connect condition is detected in said bypass current by said vehicle status detection system; and

a controller bypass system, said controller bypass system prevents said controller from manipulating said electronic switching device into said open circuit position when a critical vehicle system is in operation.

2. A battery protection system as in claim 1, wherein said short-circuit detection system inhibits said controller from instructing said electronic switching device to said closed circuit position after said short-circuit detection system detects said short-circuit.

3. A battery protection system as in claim 2, wherein said battery charge detection system is also capable of detecting a reverse polarity situation encountered by a terminal of said battery, said battery charge protection system instructs said controller to manipulate said electronic switching device into said open circuit position when said battery charge detection system detects said reverse polarity situation.

4. A battery protection system as in claim 1, wherein said battery re-connect condition is a depression of a brake pedal which illuminates a taillight, the illumination of said taillight causing a current fluctuation which is detected by said vehicle status detection system or the movement of an ignition switch from an off position to a start position, said start position causes a starter motor to activate, the activation of said starter motor causes a current fluctuation which is detected by said vehicle status detection system or the opening of a car door which illuminates an interior light, the illumination of said interior light causes a current fluctuation which is detected by said vehicle status detection system.

5. A battery protection system as in claim 1, wherein said critical vehicle system is the activation of a hazard light of the vehicle or the engine, which is operating.

6. The battery protection system as in claim 1, wherein the battery protection system is an integral part of the battery.

7. The battery protection system as in claim 1, wherein the manipulation of the said electronic switching device into said closed circuit position is transparent to the vehicle operator.

8. A method for maintaining a minimal charge value in a battery of a vehicle, comprising:

receiving a signal indicative of the charge of the battery;

receiving a signal indicative of the load on the battery;

receiving a signal indicative of the amount of time the load has been on the battery;

predicting when the charge of the battery under the present load will reach the minimal charge;

disconnecting the load from the battery before the charge of the battery will reach the minimal value by manipulating a plurality of electronic switches into an open circuit position, while allowing a small by-pass current to remain connected to the battery, the small by-pass current being insufficient to provide a starting voltage to the vehicle;

disconnecting the load when a short circuit condition has been detected;

monitoring the small by-pass current for a current fluctuation indicative of an action requiring battery reconnect; and

reconnecting the battery to the load in a transparent manner when said current fluctuation is found.

9. The method as in claim 8, wherein the current fluctuation is caused by an illumination of taillight, or the movement of an ignition switch from an off position to a start position or the illumination of an interior light of the vehicle.

10. The method as in claim 8, wherein the load is prevented from being disconnected when an engine of the vehicle is operating or the hazard lights of the vehicle are operating.

11. The method as in claim 9, wherein the load is prevented from being disconnected when an engine of the vehicle is operating or the hazard lights of the vehicle are operating.

12. The method as in claim 8, further comprising disconnecting the load when a reverse polarity has been detected at the terminals of the battery.

13. The method as in claim 11, further comprising disconnecting the load when a reverse polarity has been detected at the terminals of the battery.