Bidirectional battery charge controller

Abstract

There is disclosed a battery power supply system adapted to be installed in a portable electronic device, and a method of powering a portable electronic device. Other embodiments are also disclosed.

1 . A battery power supply system, comprising:
 a main rechargeable battery;   a cavity for receiving an additional battery, said additional battery comprising one of at least one primary cell and at least one rechargeable cell;   a single power input port for connection to an external power source; and   a bidirectional charge controller adapted to (a) control current flow between said additional battery and said main rechargeable battery, (b) regulate the charge supplied by said additional battery to said main rechargeable battery according to the state of charge of said main rechargeable battery, and (c) enable flow of current from an external power source connected to said single power input port, to said additional battery,   wherein said battery power supply system is adapted to be installed within a portable electronic device, and wherein said external power source when connected to said single power input port is configured to perform at least one of powering said device and charging at least one of said main rechargeable battery and said additional battery.   
     
     
         2 . A battery power supply system according to  claim 1 , wherein said bidirectional charge controller regulates the charge supplied by said additional battery to said main rechargeable battery by regulating the rate of supply of current to said main rechargeable battery according to the state of charge of said main rechargeable battery. 
     
     
         3 . A battery power supply system according to  claim 1 , wherein said bidirectional charge controller is further adapted to determine the battery chemistry of cells in said additional battery, and to prevent current flow into said additional battery if said additional battery comprises one or more primary cells. 
     
     
         4 . A battery power supply system according to  claim 1 , wherein said bidirectional charge controller is further adapted to regulate current supplied from said additional battery to charge said main rechargeable battery at a rate that is optimized for energy transfer from said additional battery. 
     
     
         5 . A battery power supply system according to  claim 1  and wherein said additional battery operates at a first voltage, and said bidirectional charge controller comprises a converter adapted to convert current output from said additional battery at said first voltage to another voltage for at least one of powering said device and charging said main rechargeable battery. 
     
     
         6 . A battery power supply system according to  claim 5  and wherein said converter is further adapted to convert current input from said external power source at its power source voltage to another voltage for charging said additional battery. 
     
     
         7 . A battery power supply system according to  claim 1  and wherein said additional battery comprises at least one primary cell, and wherein said power supply system initiates the drawing of current from said additional battery only when the main rechargeable battery is depleted down to a preplanned criterion. 
     
     
         8 . A battery power supply system according to  claim 1  and wherein said at least one primary cell in said additional battery is either one of an alkaline cell and a fuel cell. 
     
     
         9 . A battery power supply system according to  claim 1  and wherein said main rechargeable battery is installed socketlessly into said device. 
     
     
         10 . A battery power supply system according to  claim 1  and wherein said additional battery is readily accessible for replacement by a user. 
     
     
         11 . A battery power supply system according to  claim 1  and wherein said additional battery comprises at least one rechargeable cell, and said bidirectional charge controller preferentially draws current from said additional battery before drawing current from said main rechargeable battery. 
     
     
         12 . A battery power supply system according to  claim 1  and wherein said portable electronic device is any one of a cellular telephone, a video camera and a portable computer. 
     
     
         13 . A battery power supply system according to  claim 1  and wherein said additional battery is installed within said device. 
     
     
         14 . A battery power supply system according to  claim 4  and wherein said bidirectional charge controller converts current output from said additional battery at said first voltage to another voltage for powering said device, if said main rechargeable battery is depleted beyond a predetermined criterion. 
     
     
         15 . A battery power supply system according to  claim 1  wherein said bidirectional charge controller contains a microcontroller. 
     
     
         16 . A battery power supply system according to  claim 1  wherein said bidirectional charge controller has at least one data communication line to said electronic device. 
     
     
         17 . A battery power supply system according to  claim 1  further comprising contact taps contacting the terminals of each cell of said additional battery, such that the battery chemistry of each cell in said additional battery can be determined. 
     
     
         18 . A battery power supply system according to  claim 1  and wherein said bidirectional charge controller is configured to enable current flow into said additional battery only when said external power source is connected. 
     
     
         19 . A method of powering a portable electronic device, comprising:
 providing said portable electronic device with a battery power supply system, said battery power supply system comprising:
 a main rechargeable battery; 
 a cavity for receiving an additional battery, said additional battery comprising one of at least one primary cell and at least one rechargeable cell; 
 a single power input port for connection to an external power source; and 
 a bidirectional charge controller controlling current flow at least between said additional battery and said main rechargeable battery and between an external power source connected to said power input port and said additional battery; and 
   powering said portable electronic device by preferentially drawing current through said bidirectional charge controller from said additional battery before drawing current from said main rechargeable battery.   
     
     
         20 . A method of powering a portable electronic device according to  claim 19 , wherein said preferentially drawing current from said additional battery before drawing current from said main rechargeable battery is operative to lengthen the lifetime of said main rechargeable battery. 
     
     
         21 . A method of powering a portable electronic device according to  claim 19 , wherein said main rechargeable battery is used only after the additional battery is substantially depleted, such that the life of the main rechargeable battery is lengthened. 
     
     
         22 . A method of powering a portable electronic device according to  claim 19 , wherein said bidirectional charge controller regulates the charge supplied by said additional battery to said main rechargeable battery according to the state of charge of said main rechargeable battery. 
     
     
         23 . A method of powering a portable electronic device according to  claim 19 , wherein said bidirectional charge controller determines the battery chemistry of cells in said additional battery, and prevents current flow into said additional battery if said additional battery comprises one or more primary cells. 
     
     
         24 . A method of powering a portable electronic device according to  claim 19 , wherein said bidirectional charge controller regulates current supplied from said additional battery to charge said main rechargeable battery at a rate that is optimized for energy transfer from said additional battery. 
     
     
         25 . A method of powering a portable electronic device according to  claim 19 , wherein said additional battery operates at a first voltage, and said bidirectional charge controller comprises a converter which converts current output from said additional battery at said first voltage to another voltage for at least one of powering said device and charging said main rechargeable battery.