System and method for avoiding depleted battery in a parked vehicle

Patent metadata

Field	Value
Publication number	US-10608447-B2
Application number	US-201816004731-A
Country	US
Kind code	B2
Filing date	Jun 11, 2018
Priority date	Jun 11, 2018
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

A vehicle electrical system has a battery monitor configured to measure battery current flowing from a vehicle battery and a power management controller receiving a measured battery current value from the battery monitor. A plurality of controller modules receives the current flowing from the vehicle battery, each controller module being coupled to the power management controller to exchange communication signals. The power management controller detects a key-off state wherein the plurality of controller modules are each configured to invoke a respective reduced-power mode. When the battery load exceeds a sleep threshold during the key-off state then the power management controller resets at least one of the modules to re-invoke the respective reduced-power mode. The resetting can involve cycling a status of an ignition signal from ON to OFF.

First claim

What is claimed is:

1. A method of limiting battery drain in a vehicle electrical system having a battery monitor configured to measure battery current flowing from a vehicle battery, a power management controller receiving a measured battery current value from the battery monitor, and an ignition switch for manually determining an ignition status signal, the method comprising the steps of:
detecting a key-off state wherein a plurality of controller modules are each configured to invoke a respective reduced-power mode, wherein the plurality of controller modules receive the current flowing from the vehicle battery and are coupled to the power management controller to exchange communication signals;
monitoring the measured battery current value during the key-off state;
if the measured battery current value exceeds a sleep threshold then resetting at least one of the controller modules to re-invoke the respective reduced-power mode, wherein the resetting by the power management controller is comprised of automatically cycling the ignition status signal from an ON status to an OFF status.

2. The method of claim 1 wherein the plurality of controller modules includes at least one module receiving power through a relay, and wherein the resetting step is comprised of turning off the relay.

3. The method of claim 1 wherein one of the controller modules is a sub-net module within a sub-net for which power is controlled by another module, and wherein the resetting step is comprised of cycling power to the sub-net.

4. The method of claim 1 wherein all of the plurality of modules are reset in the resetting step.

5. The method of claim 1 further comprising the step of:
identifying a faulted module within the plurality of controller modules that has failed to invoke its reduced-power state;
wherein the faulted module is targeted by the resetting step.

6. The method of claim 5 wherein the identifying step is comprised of:
comparing respective awake-time values measured by respective controller modules to an elapsed time since a user manually set the ignition status signal to an OFF status.

7. The method of claim 1 wherein the key-off state is detected by comparing an elapsed time since a user manually set the ignition status signal to an OFF status with a predetermined delay.

8. The method of claim 1 wherein at least some of the respective reduced-power modes are comprised of a respective sleep mode in which a respective controller module suspends its control functions.

9. The method of claim 8 wherein the sleep threshold is greater than a combined battery current of the controller modules having a respective sleep mode.

10. The method of claim 1 wherein at least some of the respective reduced-power modes are comprised of a zero battery load.

11. A vehicle electrical system comprising:
a battery monitor configured to measure battery current flowing from a vehicle battery;
a power management controller receiving a measured battery current value from the battery monitor;
an ignition switch for manually determining an ignition status signal; and
a plurality of controller modules receiving the current flowing from the vehicle battery and coupled to the power management controller to exchange communication signals;
wherein the power management controller detects a key-off state wherein the plurality of controller modules are each configured to invoke a respective reduced-power mode; and
wherein when the battery current exceeds a sleep threshold during the key-off state then the power management controller resets at least one of the modules to re-invoke the respective reduced-power mode; and
wherein the resetting by the power management controller is comprised of automatically cycling the ignition status signal from an ON status to an OFF status.

12. The system of claim 11 wherein the plurality of controller modules includes at least one module receiving power through a relay, and wherein the resetting by the power management controller is comprised of turning off the relay.

13. The system of claim 11 wherein all of the plurality of modules are reset in response to the battery current exceeding the sleep threshold.

14. The system of claim 11 wherein the power management controller identifies a faulted module within the plurality of controller modules that has failed to invoke its reduced-power state, and wherein the faulted module is reset by the power management controller.

15. The system of claim 11 wherein the power management controller identifies the faulted module by comparing respective awake-time values measured by respective controller modules to an elapsed time since a user manually set the ignition status signal to an OFF status.

16. The system of claim 11 wherein the key-off state is detected by comparing an elapsed time since a user manually set the ignition status signal to an OFF status with a predetermined delay.

17. A vehicle electrical system comprising:
a battery monitor configured to measure battery current flowing from a vehicle battery;
a power management controller receiving a measured battery current value from the battery monitor; and
a plurality of controller modules receiving the current flowing from the vehicle battery and coupled to the power management controller to exchange communication signals,
wherein one of the controller modules is a sub-net module within a sub-net for which power is controlled by another module;
wherein the power management controller detects a key-off state wherein the plurality of controller modules are each configured to invoke a respective reduced-power mode;
wherein when the battery current exceeds a sleep threshold during the key-off state then the power management controller resets at least one of the modules to re-invoke the respective reduced-power mode; and
wherein the resetting by the power management controller is comprised of cycling power to the sub-net.

18. The system of claim 17 wherein the plurality of controller modules includes at least one module receiving power through a relay, and wherein the resetting by the power management controller is comprised of turning off the relay.

19. The system of claim 17 wherein the power management controller identifies a faulted module within the plurality of controller modules that has failed to invoke its reduced-power state, and wherein the faulted module is reset by the power management controller.

Assignees

• Ford Global Tech Llc

Inventors

• Varughese Sibu

Classifications

• G01R31/378

  specially adapted for the type of battery or accumulator · CPC title

• G01R31/382

  Arrangements for monitoring battery or accumulator variables, e.g. SoC · CPC title

• B60R16/03 Primary

  for supply of electrical power to vehicle subsystems {or for (circuit arrangements for charging batteries H02J7/00)} · CPC title

• B60R16/033 Primary

  characterised by the use of electrical cells or batteries (for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36) · CPC title

• H02J2007/004

  Electricity · mapped topic