Battery charger

Abstract

A battery charger with charging parameter values derived from communication with a battery pack to be charged. Communication is over a one-wire bus with battery pack transmissions in response to charger inquiries. The battery charger may be in the form an integrated circuit driving a power transistor or other controllable DC supply. A battery pack may contain a program with multiple charging currents and charging interval termination methods such as time, temperature rise, and incremental voltage polarity. A lack of communication may be invoke a default charging program or denial of access to the charger. The charger also communicates over a high-speed three-wire bus with an external computer for analysis of identification information acquired from the battery and for control of the charger.

What is claimed is:  
     
         1 . A battery charger, comprising: 
 (a) a current source coupled to an output terminal;    (b) a communication terminal ; and    (c) a controller controlling said current source in response to a charging parameter value, said controller including communication circuitry coupled to said communication terminal;    (d) wherein said controller can acquire said charging parameter value from a battery connected to said output terminal and having a communication module connected to said communication terminal.    
     
     
         2 . The charger of  claim 1 , wherein: 
 (a) said current source includes a current level detector with output connected to said controller; and    (b) said charging parameter value is a current level.    
     
     
         3 . The charger of  claim 1 , wherein: 
 (a) said controller includes a voltage level detector connected to said output terminal; and    (b) said charging parameter value is a voltage level.    
     
     
         4 . The charger of  claim 1 , wherein: 
 (a) said controller includes a voltage increment detector connected to said output terminal; and    (b) said charging parameter value is a voltage increment polarity.    
     
     
         5 . The charger of  claim 1 , wherein: 
 (a) said controller includes a temperature increment detector connected to a temperature sensor input terminal; and    (b) said charging parameter value is a temperature increment.    
     
     
         6 . The charger of  claim 1 , wherein: 
 (a) said controller includes access identification analysis circuitry; and    (b) said charging parameter value is an access identification.    
     
     
         7 . The charger of  claim 6 , wherein: 
 (a) said access identification analysis circuitry includes a second communication terminal, whereby said controller can communicate with an access identification nanlyzer.    
     
     
         8 . A battery charger control unit, comprising: 
 (a) a current control output terminal;    (b) a communication terminal; and    (c) a controller connected to said terminals, wherein said controller includes communication circuitry which can acquire charging parameter values from a battery having a communication module connected to said communication terminal, and wherein said controller includes a driver connected to said current control output terminal and which can control a current source charging said battery, said driver controlled by said acquired charging parameter values.    
     
     
         9 . The control unit of  claim 8 , wherein: 
 (a) said communication circuitry can provide power at said communication terminal to said communication module for communication.    
     
     
         10 . The control unit of  claim 8 , wherein: 
 (a) said controller includes a voltage level detector connected to a voltage level input terminal;    (b) said controller includes a current level detector connected to first and second current level detector input terminals;    (c) said controller includes first and second temperature level detectors connected to first and second temperature level input terminals;    (d) said controller includes second communication circuitry connected to a second communication terminal;    (e) wherein said charging parameter values include voltage level, current level, temperature levels, identification information; and    (f) whereby said controller can acquire (1) temperature information from temperature sensors connected to said first and second temperature level input terminals, (2) voltage information from said voltage level input terminal and (2) identification information analysis from communication over said second communication terminal, and said controller can compare said charging parameter values with outputs of said voltage level detector, said curent level detector, and said temperature level detectors, and said identification information analysis to control said driver.    
     
     
         11 . A method of battery charging, comprising the steps of: 
 (a) acquiring charging parameter values from a battery by electronic communication; and    (b) using said parameter values to control charging of said battery.    
     
     
         12 . The method of  claim 11 , wherein: 
 (a) said communication is one-wire communication in which said acquiring includes providing power to said battery for communication.    
     
     
         13 . The method of  claim 11 , wherein: 
 (a) said charging parameter values include battery voltage level and charging current level.    
     
     
         14 . The method of  claim 11 , wherein: 
 (a) said using said parameter values includes comparing one of said parameter values with a measured value.