Rechargeable battery controller

• US 5,187,425 A
• Filed: 11/09/1990
• Issued: 02/16/1993
• Est. Priority Date: 11/09/1990
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: AST Research, Inc. (Samsung Group)
• Inventors: Tanikawa, Roy K.
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): Dougherty, Thomas M.
• Application Number:
  US07/612,218
• Time in Patent Office: 830 Days
• Field of Search: 320/31, 320/35
• US Class Current: 320/138
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

A battery monitor system is disclosed comprising a microcontroller which monitors voltage inputs from a power adapter and a rechargeable battery. The power adapter includes a voltage source and a current source which outputs two current levels. A thermistor is thermally coupled to the battery, and the microcontroller receives voltage inputs from the battery and the thermistor. The microcontroller monitors and processes the voltage inputs to detect a predetermined voltage change corresponding to a change in the battery temperature and/or voltage level which indicates a fully charged battery. The level of the current which is provided to the battery from the current source is under the control of the microcontroller, such that the battery is maintained in a fully charged state.

Claims

1. A battery controller for controlling and monitoring a rechargeable battery comprising:

an adapter that includes a voltage source output providing a first source of DC power and a current output, said adapter further including a power available output indicating when said adapter is connected to an external source of power, said adapter further including a control input that receives a control signal, said adapter varying the level of said current output in response to said control signal;

a rechargeable battery assembly, that includes said rechargeable battery, said assembly further comprising an input connected to said current output of said adapter and an output providing a second source of DC voltage, said assembly having a thermistor thermally coupled to said rechargeable battery, wherein said thermistor is responsive to the temperature of said battery;

a relay that has a first input connected to said first source of DC power and a second input connected to said second source of DC power, said relay further comprising a control input, wherein said control input selects either said first or said second source of DC power as an output;

a backup battery;

a reference voltage source; and

a microcontroller which controls and monitors the charging operation of said rechargeable battery, said microcontroller including an input connected to said backup battery to monitor the voltage of said backup battery, an input connected to said thermistor to monitor temperature changes in said rechargeable battery, an input connected to said reference voltage source, an input connected to said power available output of said adapter to monitor the status of said adapter, and an input connected to said rechargeable battery to monitor the voltage level of said rechargeable battery, said microcontroller having a first output connected to said control input of said relay wherein said first output controls the selection of said first or said second source of DC power to said relay output, said microcontroller having a second output connected to said control input of said adapter wherein said second output controls said level of said current output connected to said rechargeable battery, thereby controlling the charging operation of said rechargeable battery.

2. The battery controller defined in claim 1, wherein said controller further includes a memory unit connected to said microcontroller for storing status information relating to said battery.

3. The battery controller defined in claim 1, wherein said microcontroller is further connected to a keyboard interface.

4. The battery controller defined in claim 3 wherein said memory unit further stores temperature and charge parameters relating to said battery, wherein said parameters are downloadable from said keyboard interface.