Battery management system employing software controls upon power failure to estimate battery duration based on battery/equipment profiles and real-time battery usage

• US 20020138772A1
• Filed: 03/22/2001
• Published: 09/26/2002
• Est. Priority Date: 03/22/2001
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Crawford, Timothy James, Derenburger, Jack Harvey
• Application Number:
  US09/814,596
• Publication Number:
  US 20020138772A1
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24

Abstract

A power management system uses software to predictively estimate remaining battery endurance by considering battery usage in context of a predetermined battery output and equipment load profiles, and appropriately issuing a shutdown alert or commencing a shutdown event as the end of battery endurance nears. More particularly, a battery supplies power to electrical equipment when a primary power source fails. Initially, the system receives one or more estimates of the battery'"'"'s endurance and capability of supplying electrical power to the equipment. The system tracks battery use by prescribed electrical equipment. Utilizing software, for example, the system determines when estimated endurance minus battery usage equals a predetermined difference. Relative to this time, the system takes appropriate action(s) such as initiating shutdown of the equipment or issuing a shutdown alert.

Claims

1. A power management method for use in a system including electrically powered equipment utilizing a primary power source where a battery provides backup power during failure of the primary power source, the method comprising operations of:

monitoring charge state of the battery including whether the battery is substantially fully charged;

monitoring cumulative on-battery time of the equipment since a most-recent substantially full charge of the battery;

monitoring condition of the primary power source including whether the primary power source has failed, and

responsive to each failure of the primary power source, applying a predetermined formula to compute a remaining battery endurance, and starting a timer to track expiration of the remaining battery endurance;

responsive to each restoration of the primary power source, stopping the timer;

responsive to the timer reaching a predetermined level, commencing one or more predetermined shutdown actions.

2. The method of claim 1, the computation of the remaining battery endurance including a safety margin.

3. The method of claim 1, the shutdown actions comprising:

commencing shutdown of the electrically powered equipment.

4. The method of claim 1,

the operation of monitoring charge state of the battery comprising estimating that the battery is substantially fully charged responsive to the battery receiving charge for a prescribed period of time.

5. The method of claim 1, where:

the operation of applying the predetermined formula comprises determining whether the battery has previously reached full charge, and if not establishing the remaining battery endurance as an estimated partial charge battery endurance, otherwise establishing the remaining battery endurance as an estimated full charge battery endurance minus any cumulative on-battery time.

6. The method of claim 1, where the operation of applying the predetermined formula comprises:

determining whether the battery has previously reached full charge, and if so, establishing the remaining battery endurance as an estimated full-charge battery endurance minus an estimated shut down period minus any cumulative on-battery time.

7. The method of claim 1, where the operation of applying the predetermined formula comprises:

determining whether the battery has previously reached full charge, and if not establishing the remaining battery endurance as an estimated partial-charge battery endurance minus an estimated shut down period.

8. The method of claim 7, where the operations are performed by a power manager and further comprise:

estimating the partial-charge battery endurance by performing operations comprising estimating battery endurance starting at a level of battery power that would be achieved by charging the battery for an amount of time required for the power manager to boot up.

9. A method of managing backup battery power in a system where a battery supplies power to electrical equipment when a primary power source fails, comprising operations of:

receiving one or more estimates of endurance of the battery to supply electrical power to the equipment;

tracking battery use by the electrical equipment;

utilizing software to determine when estimated endurance minus battery use equal a predetermined difference, and responsive thereto commencing one or more predetermined shutdown actions.

10. A method of managing backup battery power, comprising the operations of calculating a cumulative amount of time that prescribed equipment has been running on battery power since full charge of the battery, and utilizing the calculation to provide a output indicating an amount of time that the equipment can continue to operate on battery power before exhausting a predetermined battery endurance.

11. A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a power management method for use in a system including electrically powered equipment utilizing a primary power source where a battery provides backup power during failure of the primary power source, the method comprising operations of:

monitoring charge state of the battery including whether the battery is substantially fully charged;

monitoring cumulative on-battery time of the equipment since a most-recent substantially full charge of the battery;

monitoring condition of the primary power source including whether the primary power source has failed, and

responsive to each failure of the primary power source, applying a predetermined formula to compute a battery endurance, and starting a timer to track expiration of the remaining battery endurance,

responsive to each restoration of the primary power source, stopping the timer;

responsive to the timer reaching a predetermined level, commencing one or more predetermined shutdown actions.

12. The medium of claim 11, the shutdown actions comprising:

commencing shutdown of the electrically powered equipment.

13. The medium of claim 11, the operations further comprising:

the operation of monitoring charge state of the battery comprising estimating that the battery is substantially fully charged responsive to the battery receiving charge for a prescribed period of time.

14. The medium of claim 11, where:

the operation of applying the predetermined formula comprises determining whether the battery has previously reached full charge, and if not establishing the battery endurance remaining as an estimated partial charge battery endurance, otherwise establishing the remaining battery endurance as an estimated full charge battery endurance minus any cumulative on-battery time.

15. The medium of claim 11, where the operation of applying the predetermined formula comprises:

determining whether the battery has previously reached full charge, and if so, establishing the remaining battery endurance an estimated full-charge battery endurance minus an estimated shut down period minus any cumulative on-battery time.

16. The medium of claim 11, where the operation of applying the predetermined formula comprises:

determining whether the battery has previously reached full charge, and if not establishing the remaining battery endurance as an estimated partial-charge battery endurance minus an estimated shut down period.

17. The medium of claim 16, where the operations are performed by a power manager and further comprise:

estimating the partial-charge battery endurance by performing operations comprising estimating a battery endurance starting at a level of battery power that would be achieved by charging the battery for an amount of time required for the power manager to boot up.

18. A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a process of managing backup battery power in a system where a battery supplies power to electrical equipment when a primary power source fails, the process comprising operations of:

receiving one or more estimates of endurance of the battery to supply electrical power to the equipment;

tracking battery use by the equipment;

determining when estimated endurance minus battery use equal a predetermined difference, and responsive thereto commencing one or more predetermined shutdown actions.

19. A logic circuit of multiple interconnected electrically conductive elements configured to perform a process of managing backup battery power in a system where a battery supplies power to electrical equipment when a primary power source fails, the process comprising operations of:

receiving one or more estimates of endurance of the battery to supply electrical power to the equipment;

tracking battery use by the equipment;

determining when estimated endurance minus battery use equal a predetermined difference, and responsive thereto commencing one or more predetermined shutdown actions.

20. A power management system, comprising:

battery power source providing backup power to electrically powered equipment during failure of a primary power source;

a sensor of primary power source failure;

a timer;

a power manager programmed to perform operations comprising;

monitoring charge state of the battery including whether the battery is substantially fully charged;

monitoring cumulative on-battery time of the equipment since a most-recent substantially full charge of the battery;

monitoring condition of the primary power source including whether the primary power source has failed, and

responsive to each indication by the sensor of failure of the primary power source, applying a predetermined formula to compute remaining battery endurance, and starting the timer to track expiration of the remaining battery endurance;

responsive to each restoration of the primary power source, stopping the timer;

responsive to the timer reaching a predetermined level, commencing one or more predetermined shutdown actions.

21. The system of claim 20, further comprising the electrically powered equipment.

22. A backup power system, comprising:

a battery;

a sensor of battery use;

a power manager coupled to the battery and the sensor and programmed to perform operations comprising;

receiving one or more estimates of endurance of the battery to supply electrical power to prescribed electrical equipment;

tracking battery use by the equipment;

determining when estimated endurance minus battery use equal a predetermined difference and responsive thereto commencing one or more predetermined shutdown actions.

23. A backup power system, comprising:

a battery;

sensor means for detecting battery use;

processing means coupled to the battery and the sensor means for receiving one or more estimates of endurance of the battery to supply electrical power to the prescribed electrical equipment, tracking battery use by the equipment, and determining when estimated endurance minus battery use equal a predetermined difference, and responsive thereto commencing one or more predetermined shutdown actions.