Advanced battery controller with state of charge control

• US 6,271,642 B1
• Filed: 12/02/1998
• Issued: 08/07/2001
• Est. Priority Date: 02/13/1998
• Status: Expired due to Fees

• Current Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Dougherty, Thomas J., Iverson, Michael E., Segall, William P.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/204,207
• Time in Patent Office: 979 Days
• Field of Search: 320/104, 320/103, 320/132, 320/162, 429/9, 429/90
• US Class Current: 320/104
• CPC Class Codes: G08B 29/181 due to failing power supply
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Battery powered equipment is provide with a controller which monitors the voltage supplied by the battery. Should the battery voltage drop below a preset level when the equipment is inactive, the controller disconnects non-essential loads of the equipment from the battery to conserve what charge remains in the battery. When used with a motor vehicle the controller may be tied into the security system and disable the ignition during inactive periods unless the proper reactivation signal is received.

Claims

1. In a vehicle having an electric motor for starting an engine, an alternator driven by the engine to generate electricity, and vehicle loads, a battery system comprising:

a first battery for selectively powering the electric motor to start the engine, the first battery having a first charge level;

a second battery to operate and maintain the vehicle loads, the second battery being connected to the alternator and having a second charge level;

a charging switch in a first circuit path between the first battery and the second battery and the alternator, the charging switch connecting the first battery to the second battery and the alternator;

a charge maintenance device in a second circuit path between the first battery and the second battery and the alternator for charging the first battery to a predefined level; and

a controller coupled to the first battery to monitor the first charge level and coupled to the second battery to monitor the second charge level, the controller enabling and disabling the charge maintenance device in response to the first charge level, and the controller opening and closing the charging switch in response to the second charge level.

2. The battery system of claim 1 wherein:

the second battery has an absorptive glass mat type construction.

3. The battery system of claim 2 wherein:

the second battery has a relatively high reserve capacity and is adapted to provide a relatively low-rate discharge for an extended period of time.

4. The battery system of claim 1 wherein:

the controller enables the charge maintenance device in response to the first charge level being less than a first threshold, and disables the charge maintenance device in response to the first charge level being greater than a second threshold, the first threshold being less than the second threshold.

5. The battery system of claim 1 wherein:

the controller closes the charging switch in response to second charge level being less than a first threshold, and opens the charging switch in response to the second charge level being greater than a second threshold, the first threshold being less than the second threshold.

6. The battery system of claim 1 further comprising:

a switchable device in a circuit path between accessory electrical loads and the second battery, the switchable device being connected to the controller,

wherein the controller operates the switchable device in response to the second charge level to connect or disconnect the accessory electrical loads and the second battery.

7. The battery system of claim 1 further comprising:

a switchable device in a circuit path between an ignition circuit and the second battery, the switchable device being connected to the controller; and

a receiver connected to the controller, the receiver receiving and processing a first signal from a transmitter and outputting a second signal to the controller,

wherein the controller operates the switchable device in response to the second signal to connect or disconnect the ignition circuit and the second battery.

8. The battery system of claim 1 wherein:

the charge maintenance device responds to an enable signal from the controller by applying a series of current pulses to recharge the first battery.

9. The battery system of claim 1 wherein:

wherein the controller is suitable for enabling and disabling the charge maintenance device when the alternator is not producing electricity.

10. The battery system of claim 1 wherein:

the controller is suitable for enabling the charge maintenance device for a predetermined time period.

11. The battery system of claim 1 wherein:

the controller closes the charging switch after engine starting until the first battery is charged.

12. In a vehicle having an electric motor for starting an engine, an alternator driven by the engine to generate electricity, and vehicle loads, a battery system comprising:

a first battery for selectively powering the electric motor to start the engine, the first battery having a first voltage level;

a second battery to operate and maintain the vehicle loads, the second battery being connected to the alternator and having a second voltage level;

a charging switch in a first circuit path between the first battery and the second battery and the alternator, the charging switch connecting the first battery to the second battery and the alternator;

a charge maintenance device in a second circuit path between the first battery and the second battery and the alternator for charging the first battery to a predefined voltage level; and

a controller coupled to the first battery to monitor the first voltage level and coupled to the second battery to monitor the second voltage level,

wherein the controller enables the charge maintenance device in response to the first voltage level being less than a first reference voltage, and disables the charge maintenance device in response to the first voltage level being greater than a second reference voltage, the first reference voltage being less than the second reference voltage, and

the controller closes the charging switch in response to second voltage level being less than a third reference voltage, and opens the charging switch in response to the second voltage level being greater than a fourth reference voltage, the third reference voltage being less than the fourth reference voltage.

13. The battery system of claim 12 further comprising:

a switchable device in a circuit path between accessory electrical loads and the second battery, the switchable device being connected to the controller,

wherein the controller operates the switchable device in response to the second charge level to connect or disconnect the accessory electrical loads and the second battery.

14. The battery system of claim 12 further comprising:

a switchable device in a circuit path between an ignition circuit and the second battery, the switchable device being connected to the controller; and

a receiver connected to the controller, the receiver receiving and processing a first signal from a transmitter and outputting a second signal to the controller,

wherein the controller operates the switchable device in response to the second signal to connect or disconnect the ignition circuit and the second battery.

15. The battery system of claim 12 wherein:

the charge maintenance device responds to an enable signal from the controller by applying a series of current pulses to recharge the first battery.

16. The battery system of claim 12 wherein:

the controller is suitable for enabling the charge maintenance device for a predetermined time period.

17. The battery system of claim 12 wherein:

the controller closes the charging switch after engine starting until the first battery is charged.

18. In a vehicle having an electric motor for starting an engine, an alternator driven by the engine to generate electricity, and vehicle loads, a battery system comprising:

a first battery for selectively powering the electric motor to start the engine, the first battery having a first voltage level;

second battery to operate and maintain the vehicle loads, the second battery being connected to the alternator and having a second voltage level;

a charging switch in a first circuit path between the first battery and the second battery and the alternator, the charging switch connecting the first battery to the second battery and the alternator;

a charge maintenance device in a second circuit path between the first battery and the second battery and the alternator for charging the first battery to a predefined voltage level; and

a controller coupled to the first battery to monitor the first voltage level and coupled to the second battery to monitor the second voltage level,

wherein the controller enables the charge maintenance device in response to the first voltage level being less than a first reference voltage, and disables the charge maintenance device in response to the first voltage level being greater than a second reference voltage, the first reference voltage being less than the second reference voltage, and

the controller closes the charging switch in response to second voltage level being less than a third reference voltage, and opens the charging switch in response to the second voltage level being greater than a fourth reference voltage, the third reference voltage being less than the fourth reference voltage, and

the controller closes the cging switch after engine starting until the first battery is charged, and

the charge maintenance device responds to an enable signal from the controller by applying a series of current pulses to recharge the first battery.

19. The battery system of claim 18 further comprising:

a switchable device in a circuit path between accessory electrical loads and the second battery, the switchable device being connected to the controller,

wherein the controller operates the switchable device in response to the second charge level to connect or disconnect the accessory electrical loads and the second battery.

20. The battery system of claim 19 further comprising:

a second switchable device in a circuit path between an ignition circuit and the second battery, the second switchable device being connected to the controller; and

a receiver connected to the controller, the receiver receiving and processing a first signal from a transmitter and outputting a second signal to the controller,

wherein the controller operates the second switchable device in response to the second signal to connect or disconnect the ignition circuit and the second battery.