Battery system

• US 20020008495A1
• Filed: 07/23/2001
• Published: 01/24/2002
• Est. Priority Date: 02/13/1998
• Status: Active Grant

• Current Assignee: CPS Technology Holdings, LLC
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Iverson, Michael E., Segall, William P., Dougherty, Thomas J.
• Granted Patent: US 6,452,361 B2
• Time in Patent Office: Days
• 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 an engine to generate electricity, and accessory electrical loads;

a battery system comprising;

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

a second battery to operate and maintain accessory electrical loads, and having a second charge level;

a charge maintenance device connecting the first battery to the second battery for maintaining a charge of the first battery to a predefined level; and

a controller coupled to the first battery to monitor the first charge level, and operating the charge maintenance device in response to the first charge level.

2. The battery system as recited in claim 1 wherein the second battery has an absorptive glass mat type construction.

3. The battery system as recited in 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 as recited in claim 1 wherein the controller activates the charge maintenance device when the first battery requires charging while the alternator is not generating electricity.

5. The battery system as recited in claim 1 further comprising a charging switch connecting the first battery to the alternator and being connected to the controller, wherein the controller operates the charging switch in response to voltage across the second battery.

6. The battery system as recited in claim 5 wherein the controller closes the charging switch in response to the voltage across the second battery being greater than a first threshold, and opens the charging switch in response to the voltage across the second battery being less than a second threshold.

7. The battery system as recited in claim 6 wherein the second threshold is less than the first threshold.

8. The battery system as recited in claim 1 further comprising a power switch which connects the accessory electrical loads to one of the first battery and the second battery, and which is connected to the controller, wherein the controller operates the power switch in response to voltage across the second battery.

9. The battery system as recited in claim 1 further comprising a power switch which connects the accessory electrical loads to the first battery, and which is connected to the controller, wherein the controller operates the power assembly to disconnect accessory electrical loads when voltage across the second battery is below a given threshold.

10. The battery system as recited in claim 1 wherein the charge maintenance device responds to a control signal from the controller by applying a series of currect pulse to recharge the first battery.

11. In a vehicle having an electric motor for starting an engine, an alternator driven by an engine to generate electricity, and accessory electrical loads;

a battery system comprising;

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

a second battery to operate and maintain accessory electrical loads, and having a second voltage level;

a charging switch connecting the first battery to the alternator;

a charge maintenance device connecting the first battery to the second battery to maintain the charge level of the first battery to a predefined magnitude in response to a control signal; and

a controller coupled to both the first battery and the second battery to monitor the first voltage level and the second voltage level, and operating the charging switch and the charge maintenance device in response to the first voltage level and the second voltage level.

12. The battery system as recited in claim 11 wherein the controller produces the control signal thereby activating the charge maintenance device when the first battery requires charging while the alternator is not generating electricity.

13. The battery system as recited in claim 11 wherein the controller closes the charging switch in response to the second charge level being greater than a first threshold, and opens the charging switch in response to the second charge level being less than a second threshold.

14. The battery system as recited in claim 13 wherein the second thresold is less than the first threshold.

15. The battery system as recited in claim 11 further comprising a power switch which connects the accessory electrical loads to the first battery and which is connected to the controller, wherein the controller operates the power switch in response to the second charge level.

16. The battery system as recited in claim 11 further comprising a power switch which connects the accessory electrical loads to the first battery and which is connected to the controller, wherein the controller operates the switch assembly to disconnect accessory electrical loads when the second charge level is below a given threshold.

17. The battery system as recited in claim 11 wherein the charge maintenance device responds to the control signal by applying a series of currect pulse to recharge the first battery.