Apparatus and method to measure energy capacity of a backup power supply without compromising power delivery

Abstract

A device includes a backup power supply configured to provide power to an external system upon loss of primary system power. The backup power provided by at least one capacitor. While the capacitor is available as a backup power supply to the external system, a transient elevation of the capacitor's stored potential is created above an upper predetermined operating potential of the capacitor. Measurements of a capacitor's output voltage are obtained during the transient elevation of the capacitor's stored potential. A capacitance of the capacitor is determined from the measurements.

What is claimed is: 
     
         1 . A device, comprising:
 a backup power supply configured to provide power to a an external system upon loss of primary system power, the backup power provided by at least one capacitor, the backup power supply configured to charge the capacitor to an upper predetermined operating potential sufficient to provide enough energy to complete a memory backup operation upon loss of primary system power;   logic to create generate, while the capacitor is available as a backup power supply to the external system, a transient elevation of the capacitor's stored potential above the upper predetermined operating potential of the capacitor;   logic to coordinate the generation of the transient elevation of the capacitor's stored potential with obtain measurements of the capacitor's output voltage during the transient elevation of the capacitor's stored potential; and   logic to determine a capacitance of the capacitor from the measurements.   
     
     
         2 . The device of  claim 1 , further comprising:
 logic to obtain coordinate the measurements during with an increasing phase of the capacitor's stored potential during the transient elevation.   
     
     
         3 . The device of  claim 1 , further comprising:
 logic to obtain coordinate the measurements during with a decreasing phase of the capacitor's stored potential during the transient elevation.   
     
     
         4 . The device of  claim 2 , further comprising:
 logic to perform, once the measurements are obtained, an accelerated discharge of the capacitor back to the capacitor's upper predetermined operating potential.   
     
     
         5 . The device of  claim 1 , further comprising:
 logic to time repeated transient elevations of the capacitor's stored potential over its upper predetermined operating potential, so that a percent of time during which the capacitor's stored potential is elevated over its upper predetermined operating potential to the time that it is not so elevated is less than 0.1%.   
     
     
         6 . (canceled) 
     
     
         7 . A memory system, comprising:
 a volatile memory;   a nonvolatile memory;   a backup power supply configured to provide power to the volatile and nonvolatile memories memory upon loss of primary system power, the backup power provided by at least one capacitor, the backup power supply configured to charge the capacitor to an upper predetermined operating potential sufficient to provide enough energy to complete a backup of the volatile memory to the nonvolatile memory upon loss of primary system power;   logic to create generate, while the capacitor is available as the backup power supply to the volatile and nonvolatile memories, a transient elevation of the capacitor's stored potential above the upper predetermined operating potential of the capacitor;   logic to coordinate the generation of the transient elevation of the capacitor's stored potential with obtain measurements of the capacitor's output voltage during the transient elevation of the capacitor's stored potential; and   logic to determine a capacitance of the capacitor from the measurements.   
     
     
         8 . The memory system of  claim 7 , further comprising:
 logic to obtain coordinate the measurements during with an increasing phase of the capacitor's stored potential during the transient elevation.   
     
     
         9 . The memory system of  claim 7 , further comprising:
 logic to obtain coordinate the measurements during with a decreasing phase of the capacitor's stored potential during the transient elevation.   
     
     
         10 . The memory system of  claim 8 , further comprising:
 logic to perform, once the measurements are obtained, an accelerated discharge of the capacitor back to the capacitor's upper predetermined operating potential.   
     
     
         11 . The memory system of  claim 7 , further comprising:
 logic to time repeated transient elevations of the capacitor's stored potential over its upper predetermined operating potential, so that a percent of time during which the capacitor's stored potential is elevated over its upper predetermined operating potential to the time that it is not so elevated is less than 0.1%.   
     
     
         12 . (canceled) 
     
     
         13 . A method, comprising:
 while at least one capacitor is available as a backup power supply to an external a system, creating a transient elevation of the capacitor's stored potential above a upper predetermined operating potential of the capacitors, the upper predetermined operating potential sufficient to provide enough energy to complete a memory backup upon loss of primary system power;   obtaining coordinating measurements of the capacitor's output potential during with the transient elevation of the capacitor's stored potential; and   determining a capacitance of the capacitor from the measurements.   
     
     
         14 . The method of  claim 13 , further comprising:
 obtaining coordinating the measurements during with an increasing phase of the capacitor's stored potential during the transient elevation.   
     
     
         15 . The method of  claim 13 , further comprising:
 obtaining coordinating the measurements during with a decreasing phase of the capacitor's stored potential during the transient elevation.   
     
     
         16 . The method of  claim 14 , further comprising:
 performing, once the measurements are obtained, an accelerated discharge of the capacitor back to the capacitor's upper predetermined operating potential.   
     
     
         17 . The method of  claim 13 , further comprising:
 timing repeated transient elevations of the capacitors' stored potential over its upper predetermined operating potential so that a percent of time during which the capacitors' stored potential is elevated over their upper predetermined operating potential to the time that they are not so elevated is less than 0.1%.   
     
     
         18 . (canceled)