Electric power supply system

Abstract

In an electric power supply system, a plurality of batteries ( 405, 406 ) are connected in series by a switch group ( 402 to 404, 407 to 409 ), and a higher voltage and a lower voltage are output through a terminal and a VOL terminal, respectively, and are respectively converted in the voltage thereof by two step-down DC-DC inverters ( 105, 106 ). During a discharge operation upon a serial connection, remaining content of the batteries is measured in a period other than the period of discharge from the batteries ( 105, 106 ), and the connection mode of the serial connection is controlled based on the remaining content, to control the discharge of the respective batteries up to the discharge capacity.

1 . An electric power supply system comprising:
 a plurality of rechargeable batteries;   a switch group; and   a cell controller;   wherein said cell controller measures a remaining content of each of said plurality of batteries, and controls said switch group so that a battery having a larger remaining content preferentially outputs.   
     
     
         2 . The electric power supply system according to  claim 1 , further comprising a control unit that sends a cell-output request signal to said cell controller,
 wherein said cell controller measures said remaining content while said cell-output request signal is not received.   
     
     
         3 . The electric power supply system according to  claim 2 , wherein said control unit detects or anticipates off-timing and generates said cell-output request signal based on said detected or anticipated off-timing. 
     
     
         4 . The electric power supply system according to  claim 1 , further comprising a control unit that sends a battery-switch control signal to said cell controller,
 wherein said cell controller controls said switch group based on said battery-switch control signal.   
     
     
         5 . The electric power supply system according to  claim 4 , wherein said control unit detects or anticipates off-timing and generates said battery-switch control signal based on said detected or anticipated off-timing. 
     
     
         6 . A portable information terminal comprising the electric power supply system according to  claim 1 . 
     
     
         7 . The cell controller comprised in the electric power supply system according to  claim 1 . 
     
     
         8 . The control unit comprised in the electric power supply system according to  claim 2 . 
     
     
         9 . An electric power supply system comprising:
 a plurality of rechargeable batteries;   a switch group; and   a cell controller;   wherein said cell controller measures a remaining content of each of said plurality of batteries, and controls said switch group so that each of said plurality of batteries is charged independently based on said remaining content.   
     
     
         10 . The electric power supply system according to  claim 9 , further comprising a control unit that sends a cell-output request signal to said cell controller,
 wherein said cell controller measures said remaining content while said cell-output request signal is not received.   
     
     
         11 . The electric power supply system according to  claim 10 , wherein said control unit detects or anticipates off-timing and generates said cell-output request signal based on said detected or anticipated off-timing. 
     
     
         12 . The electric power supply system according to  claim 9 , further comprising a control unit that sends a battery-switch control signal to said cell controller,
 wherein said cell controller controls said switch group based on said battery-switch control signal.   
     
     
         13 . The electric power supply system according to  claim 12 , wherein said control unit detects or anticipates off-timing and generates said battery-switch control signal based on said detected or anticipated off-timing. 
     
     
         14 . The electric power supply system according to  claim 9 , further comprising a control unit that sends a charge-switch control signal to said cell controller,
 wherein said cell controller controls said switch group based on said charge-switch control signal.   
     
     
         15 . The electric power supply system according to  claim 14 , wherein said control unit detects or anticipates off-timing and generates said charge-switch control signal based on said detected or anticipated off-timing. 
     
     
         16 . A portable information terminal comprising the electric power supply system according to  claim 9 . 
     
     
         17 . The cell controller comprised in the electric power supply system according to  claim 9 . 
     
     
         18 . The control unit comprised in the electric power supply system according to  claim 10 . 
     
     
         19 . An electronic power supply system comprising:
 a plurality of rechargeable batteries;   a switch group; and   a cell controller;   wherein said plurality of batteries are connected in series to output, and said cell controller selects one or more batteries of said plurality of batteries wherein said selected one or more battery is less than all of said plurality of batteries, and controls said switch group so that said selected one or more batteries outputs a larger current than that of a remaining one or more batteries that is not selected.   
     
     
         20 . The electric power supply system according to  19 , further comprising a control unit that sends a battery-switch control signal to said cell controller,
 wherein said cell controller controls said switch group based on said battery-switch control signal.   
     
     
         21 . The electric power supply system according to  claim 20 , wherein said control unit detects or anticipates off-timing and generates said battery-switch control signal based on said detected or anticipated off-timing. 
     
     
         22 . A portable information terminal comprising the electric power supply system according to  claim 19 . 
     
     
         23 . The cell controller comprised in the electric power supply system according to  claim 19 . 
     
     
         24 . The control unit comprised in the electric power supply system according to  claim 20 . 
     
     
         25 . An electric power supply system comprising:
 a plurality of rechargeable batteries;   a switch group; and   a cell controller;   wherein said plurality of batteries are connected in series when outputting, and   said cell controller controls said switch group so that less than all of said plurality of batteries is selected to be charged.   
     
     
         26 . The electric power supply system according to  claim 25 , further comprising a control unit that sends a battery-switch control signal to said cell controller,
 wherein said cell controller controls said switch group based on said battery-switch control signal.   
     
     
         27 . The electric power supply system according to  claim 26 , wherein said control unit detects or anticipates off-timing and generates said battery-switch control signal based on said detected or anticipated off-timing. 
     
     
         28 . The electric power supply system according to  claim 25 , further comprising a control unit that sends a charge-switch control signal to said cell controller,
 wherein said cell controller controls said switch group based on said charge-switch control signal.   
     
     
         29 . The electric power supply system according to  claim 28 , wherein said control unit detects or anticipates off-timing and generates said charge-switch control signal based on said detected or anticipated off-timing. 
     
     
         30 . A portable information terminal comprising the electric power supply system according to  claim 25 . 
     
     
         31 . The cell controller comprised in the electric power supply system according to  claim 25 . 
     
     
         32 . The control unit comprised in the electric power supply system according to  claim 26 . 
     
     
         33 . An electric power supply control method comprising:
 measuring a remaining content of each of a plurality of rechargeable batteries; and   upon receiving a request to output from one or more plurality of batteries, wherein one or more battery is less than all of said plurality of batteries, outputting preferentially from a battery having a larger remaining content than that of other said plurality of batteries based on said measured remaining content.   
     
     
         34 . The electric power supply control method according to  claim 33  further comprising:
 monitoring a time length of an OFF state; 
 generating a battery-switch control signal when said time length of the OFF state is detected or anticipated to be a first predetermined value or above; and 
 switching a connection of said plurality of batteries when said battery-switch control signal is generated and a switching of said plurality of batteries is requested based on said measured remaining content. 
 
     
     
         35 . The electric power supply control method according to  claim 33  further comprising:
 monitoring an time length of an OFF state; 
 generating a charge-switch control signal when said time length of the OFF state is detected or anticipated to be a second predetermined value or above; and 
 switching a connection of said plurality of batteries to a charge mode when said charge-switch control signal is generated. 
 
     
     
         36 . The electric power supply control method according to  claim 35  further comprising:
 charging said each of plurality of batteries independently based on said measured remaining content and a charge capacity when switched to said charge mode. 
 
     
     
         37 . The electric power supply control method according to  claim 34  further comprising:
 switching a connection of said plurality of batteries while a cell-output request signal is not generated. 
 
     
     
         38 . An electric power supply control method comprising:
 measuring a remaining content of each of a plurality of rechargeable batteries; and   charging said each of plurality of batteries independently based on said measured remaining content and a charge capacity.   
     
     
         39 . The electric power supply control method according to  claim 38  further comprising:
 monitoring a time length of an OFF state; 
 generating a battery-switch control signal when said time length of the OFF state is detected or anticipated to be a third predetermined value or above; and 
 switching a connection of said plurality of batteries when said battery-switch control signal is generated and a switching of said plurality of batteries is requested based on said measured remaining content. 
 
     
     
         40 . The electric power supply control method according to  claim 38  further comprising:
 monitoring an time length of an OFF state; 
 generating a charge-switch control signal when said time length of the OFF state is detected or anticipated to be a fourth predetermined value or above; and 
 switching a connection of said plurality of batteries to a charge mode when said charge-switch control signal is generated. 
 
     
     
         41 . The electric power supply control method according to  claim 39  further comprising:
 switching a connection of said plurality of batteries while a cell-output request signal is not generated.