US 5,325,041 AGranted

Automatic rechargeable battery monitoring system

OwnerJames B. Briggsinventor

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Abstract

An electronic device for monitoring the charge state of a rechargeable battery comprising a voltage sensor, a current sensor, a microprocessor, and a display. The voltage sensor is operatively connected to the microprocessor to provide to the microprocessor an electronic signal indicative of the voltage appearing across the terminals of the battery. The current sensor is operatively connected to the microprocessor to provide to the microprocessor an electronic signal indicative of the current between the terminals of the battery. Based on the signals received from the voltage and current sensors, the microprocessor calculates the total current discharge capacity of the battery and the present level of charge contained within the battery, and delivers electronic signals indicative of the total current discharge capacity and the present level of charge contained within the battery to the display means.

Claims2

Dependent claims

A method for monitoring and indicating the charge state of a rechargeable battery, said method comprising the steps of:

sampling current into and out of said battery at repeated intervals,
sampling a voltage across a pair of terminals of said battery to sense when said voltage reaches a predetermined level,
integrating the sampled current from a charge value to a discharge value,
repeating the steps of current sampling and current integration, and calculating a present level of battery charge from either a full charged state to a present charge state or a fully discharged state to said present state,
calculating a total discharge capacity of said battery based on said integration each time said battery reaches said fully discharged state, such that said total discharge capacity comprises an approximation of a true total discharge capacity of said battery,
comparing said present level of battery charge to said calculated total discharge capacity, and
displaying said present level of battery charge as a function of said total discharge capacity.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/006,683Filed 21 Jan 1993 · continuation
Priority: 9 Aug 1991
Granted: 28 Jun 1994
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G01R 31/3828
Arrangements for monitoring battery or accumulator variables, e.g. SoC: using current integration
H02J 7/947
In response to battery current: in response to integrated charge or discharge current
H02J 7/96
Regulation of charging or discharging current or voltage: in response to battery voltage
G01R 31/3648
Constructional arrangements: comprising digital calculation means, e.g. for performing an algorithm