Patent · US Expired

Battery state of charge gauge

US3946299A · kind A · utility

199Cited by
4References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 11, 1975
Grant dateMar 23, 1976
Priority date
Expiry dateFeb 11, 1995

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/389
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A circuit for detecting and indicating the actual state of charge of a storage battery in response to signals sampled from various points in the circuit powered by the battery. Such circuit is adapted to calculate the open circuit voltage of the battery, it being realized that the open circuit voltage is directly proportional to the battery state of charge. A function generator is constructed to simulate the characteristic curve of the battery relating the internal resistance to the percent charge. Feedback is provided from the output of the indicating circuitry to the bias point of the function generator for causing the generator to produce a signal related to the actual internal resistance of the battery. The circuit is adapted to provide a reliable indication of the amount of usable energy remaining in the battery, irrespective of the conditions under which the battery was discharged.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.