05650937 is referenced by 133 patents and cites 10 patents.

The battery (3), which powers an apparatus (2), supplies an auxiliary circuit for a short time (5). A test and control component (6) of the device superimposes a low amplitude current interference .DELTA.i onto the discharge current (1). The interference signal frequency f is chosen acccording to the capacity and the discharge current of the battery (3). Processing of the frequency response of the battery (3) by the test and control component provides an indication of the combined impedence of the battery at that frequency. The value Z.sub.I =(.DELTA.V/.DELTA.I) sin (.DELTA..phi.) of the imaginary part of the impedence so measured, or advantageously the value of the quantity .GAMMA.=Z.sub.I.sup.-2 f.sup.-3/2 thereby indicates the state of charge of the battery.

Title
Device and method for measuring the charge state of a nickel-cadmium accumulator
Application Number
240707
Publication Number
5650937
Application Date
July 17, 1995
Publication Date
July 22, 1997
Inventor
Abdennebi Bounaga
Evry
FR
Agent
William A Drucker
Assignee
Universite Paris Val de Marne
FR
IPC
G01N 27/416
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