Battery monitoring and charging control unit

A monitoring unit for monitoring the condition of charge of a battery, comprising:

• processor means operable during flow of charge current to said battery and discharge current from said battery for performing periodic read and processing operations, each read operation including producing a battery current reading corresponding to net current flowing to said battery, and each processing operation including producing an output reading from said battery current, and adding said output reading to a stored accumulated charge value indicating the condition of charge of said battery, said processor means being operable during inactive conditions of no flow of charge current to or discharge current from said battery for periodically performing a self-discharge correction, each self-discharge correction serving to effect a reduction in said stored accumulated charge which is a function of elapsed time while in said inactive condition and since a last preceding self-discharge correction.

A monitoring unit for monitoring the condition of charge of a battery, comprising:

• battery temperature sensing means, and processor means coupled to said temperature sensing means and operable during flow of charge current to said battery for performing periodic temperature read and temperature-responsive processing operations, each temperature read operation including producing a temperature reading proportional to the current temperature of said battery, each processing operation including processing of said temperature reading to obtain data for use in subsequent processing operations, storing of such data, comparing said temperature reading and data stored during prior processing operations to develop a dT/dt value indicating a rate of change of temperature with time and to determine whether said dT/dt value is changing, and generating a full charge signal after said dT/dt value is increasing and when said dT/dt value exceeds a certain threshold value.

A monitoring unit for monitoring the charge of a battery which may supply circuitry of a host and may be charged from a charger associated with said host, said unit comprising:

• memory means, processor means operative for gathering and storing in said memory means information concerning the voltage of, current flow to and temperature of said battery and its condition of charge being operative for sending data to said host under control of said host.

A monitoring unit comprising:

• input means for supplying an input voltage to be measured, measuring means including ramp voltage generator means for generating a ramp voltage, comparator means coupled to said input means and said ramp voltage generator means, and processor means operative for controlling periodic operation of said ramp voltage generator means and coupled to said comparator means for registering digital input voltage data corresponding to a comparison of said ramp voltage with a voltage proportional to said input voltage and digital reference data corresponding to a comparison of said ramp voltage with a subtantially fixed voltage, said processor means being operative for processing said digital input voltage and reference data to develop output digital data proportional to the magnitude of said input voltage and substantially independent of changes in slope of said ramp voltage.

A monitoring unit arranged for developing digital output data as a function of the value and polarity of an input voltage applied between an input terminal and a ground terminal, said unit comprising:

• power supply means for supplying an operating voltage between said ground terminal and a supply voltage terminal, a measurement voltage divider including a first resistance means having one end connected to said supply voltage terminal and an opposite end connected to a measurement node and second resistance means having one end connected to said measurement node and an opposite end connected to said input terminal, and measuring means including analog to digital converter means operative for measuring a voltage at said measurement node and including means for producing a digital output reading corresponding to the value and polarity of said voltage at said input terminal.

A measuring unit comprising:

• ramp voltage generator means for generating a ramp voltage, a plurality of comparator means each operative for comparing said ramp voltage and an input voltage and producing an output signal which changes in state in response to a certain difference between said ramp voltage and said input voltage, and processor means coupled to said ramp voltage means and including data storage registers and a port for input of said output signals from said plurality of comparator means, said processor means being operative to perform a read operation including initiating generation of said ramp voltage and then performing periodic test operations, each test operation including effecting a one count change in current count data, registering of port data indicating the status of said output signals from said comparator means, detecting any change in data in said port data from port data registered in a last preceding test operation and responding to any such change in data by registering change data as to said change in said plural bit digital data, said change data together with said current count data providing data as to the relative magnitude of said ramp voltage and of any input voltage which produced a change in state of any one of said plurality of comparators since said last preceding test operation.