Battery characterization technique accounting for offset error

Abstract

The present invention provides a system and method for operating a rechargeable battery, the system comprising: current maintaining device for maintaining a predetermined current to the rechargeable battery until the rechargeable battery reaches a predetermined maximum voltage; voltage maintaining device for maintaining a predetermined voltage to the rechargeable battery until a predetermined minimum current is delivered to the rechargeable battery; determining device for determining a cyclical charge value delivered to the rechargeable battery by the current maintaining device and the voltage maintaining device during a cycle; and a correction device for correcting the determining device when charge is not being delivered to the rechargeable battery, on the basis of the charge value.

What is claimed is: 
     
         1 . A power supply for an electronic device, said power supply comprising:
 a rechargeable battery source configured for cyclical charging and discharging by said electronic device;   a measuring circuit configured to measure one or more parametric data of the rechargeable battery source during said charging and discharging;   an isolation circuit configured to electrically isolate said rechargeable battery source from said electronic device; and   a testing circuit configured to test said measuring circuit for offset error during said isolation of said rechargeable battery from said electronic device.   
     
     
         2 . The power supply of  claim 1 , further comprising:
 a reducer circuit configured to reduce current flow from said rechargeable battery to said electronic device to a minimal value.   
     
     
         3 . The power supply of  claim 1 , further comprising:
 an auxiliary power source configured to provide power to said electronic device independently of said battery source.   
     
     
         4 . The power supply of  claim 3 , further comprising:
 a reducer circuit configured to reduce current flow from said rechargeable battery to said electronic device to a minimal value.   
     
     
         5 . The power supply according to  claim 1 , wherein said testing circuit is further configured to correct any offset error while said rechargeable battery source is isolated from said electronic device. 
     
     
         6 . The power supply according  claim 1 , wherein said parametric data includes cumulative charge. 
     
     
         7 . The power supply according to  claim 1 , wherein said electronic device is an implantable medical device. 
     
     
         8 . The power supply according to  claim 7 , wherein the implantable medical device is a receiver/stimulator unit of a prosthetic hearing implant system. 
     
     
         9 . The power supply according to  claim 2 , wherein the testing circuit configured to test said measuring circuit for offset error while said reducer circuit said isolation of said rechargeable reduces current flow from said rechargeable battery to said electronic device to a minimal value. 
     
     
         10 . A prosthetic hearing implant system comprising:
 a rechargeable battery source configured to be cyclically charged and discharged; and   a battery charger comprising:
 a measuring circuit configured to measure one or more parametric data of the rechargeable battery while the rechargeable battery is cyclically charged and discharged; 
 a disconnection circuit configured to isolate current flow from said rechargeable battery to a load; and 
   testing circuit configured to test said measuring circuit for offset error while said current flow is isolated from said load.   
     
     
         11 . The prosthetic hearing implant system of  claim 10 , further comprising:
 an auxiliary power source configured to power the load when said rechargeable battery source is removed from the load independently of said rechargeable battery source.   
     
     
         12 . The prosthetic hearing implant system of  claim 10 , wherein:
 said testing circuit is further configured to correct any offset error while said rechargeable battery source is isolated from said load.   
     
     
         13 . The prosthetic hearing implant system according to  claim 10 , wherein:
 said one or more parametric data includes cumulative charge.   
     
     
         14 . The prosthetic hearing implant system according to  claim 10 , wherein:
 said second charging stage commences after completion of said first charging stage.   
     
     
         15 . The prosthetic hearing implant system according to  claim 10 , wherein:
 said load is an implantable medical device.   
     
     
         16 . The prosthetic hearing implant system according to  claim 10 , wherein:
 said load is a receiver/stimulator unit of prosthetic hearing implant system.   
     
     
         17 . A battery charger comprising:
 a measuring circuit configured to measure one or more parametric data of a rechargeable battery while the rechargeable battery is cyclically charged and discharged;   a testing circuit configured to test said measuring circuit for offset error; and   a current flow control circuit configured to reduce and/or eliminate current flow from said rechargeable battery to a load,   wherein said testing circuit is enabled during said isolation of said rechargeable battery from said load.   
     
     
         18 . The battery charger of  claim 17 , wherein:
 said testing circuit is further configured to correct any offset error while said rechargeable battery source is isolated from said load.   
     
     
         19 . The battery charger of  claim 17 , wherein:
 said current flow control circuit is a disconnection circuit configured to eliminate current flow from said rechargeable battery to the load.   
     
     
         20 . The battery charger of  claim 17 , wherein:
 said current flow control circuit is configured to reduce current flow from said rechargeable battery to the load.