Method and system for regulating current discharge during battery discharge conditioning cycle

• US 20090195211A1
• Filed: 01/31/2008
• Published: 08/06/2009
• Est. Priority Date: 01/31/2008
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Chiasson, Shane, Wang, Ligong
• Granted Patent: US 8,129,946 B2
• Time in Patent Office: Days
• US Class Current: 320/136
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems

Abstract

Methods and systems are disclosed for utilizing a memory control circuit for controlling transfer of data to and from a memory system. A memory control circuit with a back up battery and control circuits is provided. Battery health is determined through a discharge cycle of the back up battery. A power supply generated from the back up battery is provided to circuitry of the memory control card during normal operations of the memory control circuit during a non-power loss state. The power supplied from the back up battery during the non-power loss state of the memory control circuit is utilized by at least a first circuit of the memory control circuit as part of normal memory controller card operations during the battery health discharge cycle. When the system is not performing a battery health cycle the first circuit receives normal system power. The memory control circuit may be a RAID card. The first circuit may be memory circuitry. The backup battery discharge rate may be regulated during the battery health discharge cycle by switching the power source for the circuitry of the memory control card between the backup battery and the normal system power.

Claims

1. A method of determining the health of a backup battery in storage memory controller circuitry, the method comprising steps of:

providing the storage memory controller system circuitry with a back up battery and other control circuits, the back up battery providing a power source during occurrences of a system power loss condition;

commencing a battery health discharge cycle of the back up battery even though normal power conditions exist with normal system power being available;

providing a power supply generated from the battery to at least some circuitry of the storage memory controller circuitry as part of the battery health discharge cycle of the back up battery that occurs while normal system power conditions exist with normal system power being available;

discharging at least a portion of the back up battery during the battery health discharge cycle of the back up battery that occurs while normal system power conditions exist;

regulating a discharge rate of current from the back up battery during the battery health discharge cycle by switching the power supply provided to at least some circuitry of the storage memory controller circuitry back and forth between the backup battery and the normal system power to reduce the current drawn from the backup battery during the battery health discharge cycle; and

determining a health of the back up battery after the discharging of at least a portion of the back up battery.

2. The method of claim 1, wherein the storage memory controller circuitry is a RAID controller card.

3. The method of claim 2, wherein the at least some circuitry of the storage memory controller circuitry comprises cache memory.

4. The method of claim 1, further comprising digitally calculating a second and average value of current rate from a first reported digital value of current rate;

regulating the discharge rate of current from the back up battery during the battery health discharge cycle by repeatedly switching the power supply provided to at least some circuitry of the storage memory controller circuitry back and forth between the backup battery and the normal system power according to a discharge duty cycle to reduce the second digitally calculated average value of current drawn over time from the backup battery during the battery health discharge cycle.

5. The method of claim 4, further comprising adjusting the discharge duty cycle to increase or decrease the second digitally calculated average value of the backup battery discharge current rate over time during the battery health discharge cycle based on said first reported digital value of current rate.

6. The method of claim 4, further comprising using a battery management unit (BMU) of a smart battery to measure said first digital value of the backup battery discharge current rate over time during the battery health discharge cycle;

reporting said measured first digital value of current rate from said BMU to at least one other processor;

using said at least one other processor to digitally calculate said second calculated average value of the backup battery discharge current rate over time from said first reported digital value of current rate;

determining if said second calculated average value of the backup battery discharge current rate over time is greater than a current threshold value or range of values; and

adjusting the discharge duty cycle to decrease said second calculated average value of the backup battery discharge current rate over time if it is determined that said second calculated average value of the backup battery discharge current rate over time is greater than the current threshold value or range of values.

7. The method of claim 4, using a battery management unit (BMU) of a smart battery to measure said first digital value of the backup battery discharge current rate over time during the battery health discharge cycle;

reporting said measured first digital value of current rate from said BMU to at least one other processor;

using said at least one other processor to digitally calculate said second calculated average value of the backup battery discharge current rate over time from said first reported digital value of current rate;

determining if said second calculated average value of the backup battery discharge current rate over time is greater than a target backup battery discharge rate or a target range of backup battery discharge rate values and adjusting the discharge duty cycle to decrease said second calculated average value of the backup battery discharge current rate over time if it is determined that said second calculated average value of the backup battery discharge current rate over time is greater than the target backup battery discharge rate or a target range of backup battery discharge rate values; and

determining if said second calculated average value of the backup battery discharge current rate over time is less than the target backup battery discharge rate or a target range of backup battery discharge rate values and adjusting the discharge duty cycle to increase said second calculated average value of the backup battery discharge current rate over time if it is determined that said second calculated average value of the backup battery discharge current rate over time is less than the target backup battery discharge rate or a target range of backup battery discharge rate values.

8. The method of claim 7, further comprising repeatedly performing each of the steps of claim 7 throughout the duration of the battery health discharge cycle to maintain said second calculated average value of the backup battery discharge current rate over time at the target backup battery discharge rate or within the target range of backup battery discharge rate values during the battery health discharge cycle.

9. The method of claim 1, further comprising charging the back up battery as part of the battery health cycle.

10. A method of utilizing a memory control circuit for controlling a transfer of data to or from a memory storage system, said method comprising steps of:

providing a RAID memory controller card having a back up battery and control circuits;

performing a battery health cycle for determining the health of the back up battery;

providing a back up battery generated power supply to circuitry of the RAID memory controller card during a non-system power loss state as part of the battery health cycle;

providing a normal system power supply separate from the backup battery to circuitry of the RAID memory controller card during a non-system power loss state as part of the battery health cycle;

discharging at least a portion of the charge of the back up battery during the non-system power loss state as part of the battery health cycle;

regulating a discharge rate of current from the back up battery during the battery health cycle by switching the power supply provided to circuitry of the RAID memory controller card back and forth between the backup battery and normal system power to reduce the current drawn from the backup battery during the battery health cycle; and

determining a condition of the back up battery as part of the battery health cycle.

11. The method of claim 10, wherein the circuitry of the RAID memory controller card that receives the battery generated power supply during a non-system power loss state as part of the battery health cycle comprises memory circuitry.

12. The method of claim 10, further comprising regulating the discharge rate of current from the back up battery during the battery health cycle by repeatedly switching the power supply provided to circuitry of the RAID memory controller card back and forth between the backup battery and normal system power according to a discharge duty cycle to reduce the average value of current drawn over time from the backup battery during the battery health cycle.

13. The method of claim 12, further comprising using a battery management unit (BMU) of a smart battery to measure said first digital value of the backup battery discharge current rate over time during the battery health discharge cycle;

reporting said measured first digital value of current rate from said BMU to at least one other processor;

using said at least one other processor to digitally calculate said second calculated average value of the backup battery discharge current rate over time from said first reported digital value of current rate;

determining if said second calculated average value of the backup battery discharge current rate over time is greater than a target backup battery discharge rate or a target range of backup battery discharge rate values and adjusting the discharge duty cycle to decrease said second calculated average value of the backup battery discharge current rate over time if it is determined that said second calculated average value of the backup battery discharge current rate over time is greater than the target backup battery discharge rate or a target range of backup battery discharge rate values; and

determining if said second calculated average value of the backup battery discharge current rate over time is less than the target backup battery discharge rate or a target range of backup battery discharge rate values and adjusting the discharge duty cycle to increase said second calculated average value of the backup battery discharge current rate over time if it is determined that said second calculated average value of the backup battery discharge current rate over time is less than the target backup battery discharge rate or a target range of backup battery discharge rate values.

14. The method of claim 13, further comprising repeatedly performing each of the steps of claim 13 throughout the duration of the battery health cycle to maintain said second calculated average value of the backup battery discharge current rate over time at the target backup battery discharge rate or within the target range of backup battery discharge rate values during the battery health cycle.

15. The method of claim 10, further comprising charging the back up battery as part of the battery health cycle.

16. An information handling system comprising:

a back up battery;

memory controller circuitry for controller the transfer of data to and from an external data storage system;

at least a first circuit within the memory controller circuitry that is operable in a normal power mode to receive normal system power in a non-power loss state, the first circuit being coupled to the back up battery during the battery health cycle so that the backup battery may be discharged by supplying operating power to the first circuit as part of the battery health cycle, the battery supplied operating power being utilized to operate the first circuit during normal data transfer between the memory controller circuitry and the external data storage system; and

at least one second circuit that is operable in a normal power mode to regulate a discharge rate of current from the back up battery during the battery health cycle by switching the power supply provided to the first circuit back and forth between the backup battery and the normal system power to reduce the current drawn from the backup battery during the battery health cycle.

17. The system of claim 16, wherein the memory controller circuitry is a RAID controller card;

wherein the first circuit is a memory circuit; and

further comprising charger circuitry coupled to the back up battery to charge the battery as part of the battery health cycle.

18. The system of claim 16, wherein the at least one second circuit is further configured to regulate the discharge rate of current from the back up battery during the battery health cycle by repeatedly switching the power supply provided to the first circuit back and forth between the backup battery and the normal system power according to a discharge duty cycle to reduce the average value of current drawn over time from the backup battery during the battery health discharge cycle.

19. The system of claim 18, further comprising a battery management unit (BMU) within said backup battery, said BMU being configured to report a first digital value of the backup battery discharge current rate over time;

wherein said at least one second circuit is configured to digitally calculate a second and average value of current rate from said first reported digital value of current rate from said BMU; and

wherein the at least one second circuit is further configured to determine if said second calculated average value of the backup battery discharge current rate over time during the battery health cycle is greater than a current threshold value or range of values, and to adjust the discharge duty cycle during the battery health cycle to decrease said second calculated average value of the backup battery discharge current rate over time if it is determined that said second calculated average value of the backup battery discharge current rate over time is greater than the current threshold value or range of values.

20. The system of claim 19, wherein the at least one second circuit is further configured to calculate said second calculated average value of the backup battery discharge current rate over time during the battery health discharge cycle based on reported measured instantaneous current discharge rate from the backup battery.

21. The system of claim 18, wherein the at least one second circuit is further configured to repeatedly determine if said second calculated average value of the backup battery discharge current rate over time during the battery health discharge cycle is greater or less than a current threshold value or range of values, and to perform the following steps in response to each repeated determination:

adjust the discharge duty cycle to decrease said second calculated average value of the backup battery discharge current rate over time during the battery health cycle if it is determined that said second calculated average value of the backup battery discharge current rate over time is greater than the target backup battery discharge rate or target range of backup battery discharge rate values; and

adjust the discharge duty cycle to increase said second calculated average value of the backup battery discharge current rate over time during the battery health cycle if it is determined that said second calculated average value of the backup battery discharge current rate over time is less than the target backup battery discharge rate or a target range of backup battery discharge rate values.