Method for charging a battery

Abstract

A method and apparatus for charging a rechargeable battery ( 110 ) that takes into account the use patterns of the particular battery. A user may only discharge the battery a little and recharge it frequently which is a low capacity high life cycle use pattern, or discharge the battery almost completely and place the battery on charge less frequently indicating a high capacity low life cycle use pattern. Herein, a battery is installed in an electronic device wherein a battery discharge determination circuit and a discharge determination algorithm determine the discharge level of the battery when a charging circuit is placed on the battery. The measurement algorithm determines from the rechargeable battery discharge level measurement how to recharge the rechargeable battery. The measurement algorithm may also determine how to recharge the rechargeable battery based on a plurality of previous measurements stored either in the electronic device or the battery.

1 . A method for recharging a rechargeable battery: 
 determining a discharge characteristic of a rechargeable battery when said rechargeable battery is coupled to a charging circuit; and    recharging said battery based on said discharge characteristic.    
   
   
       2 . The method of  claim 1 , 
 comparing said discharge characteristic to a predetermined value;    recharging said rechargeable battery to a first recharge condition if said determined discharge characteristic of said rechargeable battery is greater than said predetermined discharge characteristic value, and    recharging said rechargeable battery to a second recharge condition if said determined discharge characteristic of said rechargeable battery is less than said predetermined discharge characteristic value.    
   
   
       3 . The method of  claim 2 , determining said rechargeable battery discharge characteristic by: 
 determining a discharge voltage relative to a battery voltage capacity,    determining a number of coulombs said rechargeable battery receives during a charging cycle of said battery,    tracking, between a first charging and a second charging of said battery, a plurality of operation modes of a device adapted to accept said battery and a time associated with each mode of a plurality of operation modes, wherein each mode has an average current drain associated therewith,    determining a number of coulombs said rechargeable battery expends during the discharge of said rechargeable battery, or    determining a time between a first charge and a second charge.    
   
   
       4 . The method of  claim 1 , 
 measuring a discharge characteristic of a rechargeable battery when said rechargeable battery is coupled to a charging circuit; and    storing each rechargeable battery discharge characteristic information.    
   
   
       5 . The method of  claim 4 , 
 determining a rechargeable battery discharge level pattern from a plurality of said rechargeable battery discharge characteristic information.    
   
   
       6 . The method of  claim 5 , determining that said rechargeable battery discharge level pattern is a low capacity high cycle life pattern, a high capacity low cycle life pattern, fast charge time low cycle life pattern, or a short charge time high cycle life pattern.  
   
   
       7 . The method of  claim 6 , recharging said rechargeable battery to a voltage level between a first voltage and a second voltage; and preferably to a third voltage between said first voltage and said second voltage, in response to determining said battery charge level pattern being a low capacity high cycle life pattern.  
   
   
       8 . The method of  claim 6 , recharging said rechargeable battery to a voltage between 4.05 volts and 4.15 volts, preferably 4.1 volts in response to determining that said rechargeable battery discharge level pattern corresponds to a low capacity high cycle life pattern.  
   
   
       9 . The method of  claim 6 , recharging said battery by applying a first current in response to determining said battery charge level pattern to be a high capacity low cycle life pattern; and 
 recharging said battery by applying a second current in response to determining said battery charge level pattern to be a low capacity high cycle life pattern.    
   
   
       10 . The method of  claim 9 , wherein the ratio of said first current to said second current is between 1.5 and 4.5 and preferably 3.0.  
   
   
       11 . The method of  claim 6 , recharging said battery by applying a first current, said first current between 0.2 amps and 0.5 amps in response to determining said battery charge level pattern to be a high capacity low cycle life pattern, and 
 charging said battery by applying a second current between 0.5 amps and 2.0 amps in response to determining said battery charge level pattern being to be a low capacity high cycle life pattern.    
   
   
       12 . The method of  claim 6 , recharging said battery to a voltage between a fourth voltage and a fifth voltage, preferably a sixth voltage, in response to determining said battery charge level pattern to be high capacity low cycle life high capacity pattern.  
   
   
       13 . The method of  claim 12 , recharging said battery to a voltage between 4.15 volts and 4.2 volts, preferably 4.2 volts, in response to determining said battery charge level pattern to be high capacity low cycle life pattern.  
   
   
       14 . The method of  claim 1 , recharging said battery with a current between a first current and a second current, preferably a third current between said first and said second current, in response to determining said battery charge level pattern being a fast charge time low capacity pattern.  
   
   
       15 . The method of  claim 14 , recharging said battery with a first current to between 0.5 amps and 2.0 amps; and preferably 1.0 amps in response to determining that said battery charge level pattern is a fast charge time low cycle life pattern.  
   
   
       16 . The method of  claim 14 , charging said battery with a first current to between 0.2 amps and 0.5 amps; and preferably 0.35 amps in response to determining that said battery charge level pattern is a slow charge time high cycle life slow charge time pattern.  
   
   
       17 . The method of  claim 6 , determining a rechargeable battery discharge level pattern to be a low capacity high cycle life pattern when said battery is coupled to said charging circuit when said battery has a capacity greater than a 50 percent and when the time between charge cycles is twenty four hours or less, 
 determining a rechargeable battery discharge level pattern to be a high capacity low cycle life pattern when said battery is coupled to said charging circuit when said battery has a capacity less than a 50 percent and when the a time between charge cycles is twenty four hours or greater;    determining a rechargeable battery discharge level pattern to be a fast charge time low cycle life pattern when a battery charge time is less than one half a full charge time for said battery,    determining a rechargeable battery discharge level pattern to be a slow charge time high cycle life pattern when a battery charge time is greater than one half a full charge time for said battery,    determining a rechargeable battery discharge level pattern to be,    a slow charge high cycle life pattern, by determining that the time from when the battery has reached a full charge to the time the battery is disconnected from the charger is greater than 60 minutes, and    a fast charge low cycle life pattern, by determining that the time from when the battery has reached a full charge to the time the battery is disconnected from the charger is less than 60 minutes.    
   
   
       18 . The method of  claim 1 , storing said battery charge level value in a memory of said portable device.  
   
   
       19 . The method of claim, 1 storing said battery charge level value in a memory of a battery.  
   
   
       20 . The method of  claim 1 , storing said one of a plurality of battery charge level values in a memory in response to coupling a battery to a charging device.