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Showing papers on "State of charge published in 1989"


Patent
05 Oct 1989
TL;DR: In this article, a vehicle storage battery is monitored to determine battery capacity, state of charge and certain fault conditions, and the low temperature starting limit is determined by comparing the battery's power output capability with starting power requirements of the vehicle.
Abstract: A vehicle storage battery is monitored to determine battery capacity, state of charge and certain fault conditions. The ambient temperature, battery voltage alternator/regulator output voltage and current to and from the battery are continuously measured. Current voltage (I-V) data is analyzed to determine the internal resistance and polarization of the battery. A determination is made regarding state of charge and fault conditions produced by corroded terminals and low electrolyte level. The low temperature starting limit is determined by comparing the battery's power output capability with starting power requirements of the vehicle. Data produced by the comparison are indicated on the dashboard of the vehicle.

259 citations


Patent
16 Jun 1989
TL;DR: In this article, a self-contained electronic device for testing storage batteries that may be partially discharged is disclosed, which performs small-signal measurements of the battery's dynamic conductance and provides either a proportional numerical readout, displayed in appropriate battery measuring units, or a corresponding qualitative assessment of battery's relative conduction based upon its electrical rating.
Abstract: A self-contained electronic device for testing storage batteries that may be partially discharged is disclosed. The testing device performs small-signal measurements of the battery's dynamic conductance and provides either a proportional numerical readout, displayed in appropriate battery measuring units, or a corresponding qualitative assessment of the battery's relative conduction based upon its electrical rating. In addition, the testing device measures the battery's open-circuit (unloaded) voltage and provides adjustable means for correcting the dynamic conductance test result in inverse correspondence with the battery's open-circuit voltage relative to its fully-charged value. By virtue of this correction, the quantitative or qualitative information displayed to the user in the dynamic conductance test is adjusted to comport with that of a fully-charged battery even through the battery may, in actual fact, be only partially charged when tested.

160 citations


Patent
21 Feb 1989
TL;DR: In this paper, an aircraft storage battery is monitored to determine battery capacity, state of charge and certain fault conditions, and the low temperature starting limit is determined by comparing the battery's power output capability with starting power requirements of the aircraft.
Abstract: An aircraft storage battery is monitored to determine battery capacity, state of charge and certain fault conditions. The ambient temperature, battery voltage on-board charger output voltage and current to and from the battery are continuously measured. Current voltage (I-V) data is analyzed to determine the internal resistance and polarization of the battery. A determination is made regarding state of charge and fault conditions produced by corroded terminals and low electrolyte level. The low temperature starting limit is determined by comparing the battery's power output capability with starting power requirements of the aircraft. Data produced by the comparison are indicated on the dashboard of the vehicle.

152 citations


Patent
Jack Early1, John Werth1
11 Jan 1989
TL;DR: In this paper, a fuel cell/battery hybrid power system with a microprocessor-based control system is described, which enables the fuel cell to be taken out of the system by a switch when its predetermined maximum desired energy output is about to be exceeded by load requirements.
Abstract: A fuel cell/battery hybrid power system is disclosed which has a microprocessor based control system. The control system enables the fuel cell to be taken out of the system by a switch when its predetermined maximum desired energy output is about to be exceeded by load requirements. The battery is protected from overcharging by a switch which is activated responsive to the sensing of state of charge, load current and fuel cell current.

70 citations


Proceedings ArticleDOI
D. Mayer1, S. Biscaglia1
15 Oct 1989
TL;DR: In this paper, a model of the lead-acid battery is presented based on a simple description of electrochemical reactions, and models of the electromotive force, the internal resistance, and the gassing phenomenon are detailed.
Abstract: A model of the lead-acid battery is presented based on a simple description of electrochemical reactions. Models of the electromotive force, the internal resistance, and the gassing phenomenon are detailed. Good agreement between simulation and measurement has led to the validation of a model for discharge and for the charge preceding gassing at constant temperature. As regards the calculation of the state of charge, modeling of the gas emission is necessary to minimize drift over a long period of operation. >

37 citations


Journal ArticleDOI
25 Apr 1989
TL;DR: In this article, a fiber-optic technique for measuring relative density has been developed and successfully applied to the electrolyte of a lead-acid battery, which relies on the optical power loss exhibited by fibers bent beyond a critical radius.
Abstract: A fiber-optic technique for measuring relative density has been developed and successfully applied to the electrolyte of a lead-acid battery. The method relies on the optical power loss exhibited by fibers bent beyond a critical radius. For such fibers the loss depends on the refractive index of the surrounding medium, which is proportional to its specific gravity. The amount of leakage can be measured and related to the value of the specific gravity. The application of this technique has one main drawback: errors can arise from source intensity variations, variable losses in fibers and connectors, and sensitivity changes in the detectors. >

24 citations


Journal ArticleDOI
TL;DR: The ohmic resistance of maintenance-free lead-acid batteries has been identified as an ideal parameter for the prediction of the state-of-charge using the a.c. impedance technique.

21 citations


Journal ArticleDOI
TL;DR: In this paper, an empirical law, based on results obtained from different experiments, has been developed to isolate the accumulator state of charge as a function of the maximum state-of-charge density at the test point and a proportionality constant, n.

18 citations



Journal ArticleDOI
TL;DR: In this article, the authors proposed an online method based on simple electrical measurements combined with a new electrolyte agitation technique which avoids systematic control of the battery state-of-charge, which is very accurate and reduces the standard error in the state of charge prediction.

6 citations



Patent
21 Nov 1989
TL;DR: In this paper, the residual capacity of an accumulator obtained by the integration of amounts of charge or discharge is subjected to interrupt correction by a residual capacity determined by a change in a terminal voltage or specific gravity.
Abstract: PURPOSE:To increase the precision in detection and to enable the improvement in reliability, by a method wherein a residual capacity of an accumulator obtained by the integration of amounts of charge or discharge is subjected to interrupt correction by a residual capacity determined by a change in a terminal voltage or specific gravity. CONSTITUTION:A shunt 3 provided in a part of a wiring 1 connecting a power source or a load with a battery 2 converts a current into a voltage signal being proportional to a charge and a discharge. Subsequently, a clock signal obtained by a signal amplifier element 6 and a supplied voltage/frequency converter element 10 and the result of judgement by a charge/discharge detecting element 7 on the state of charge or discharge of the current flowing through the wiring 1 are supplied to a counter element 11. In the counter element 11, addition or subtraction is executed at the time of charge or discharge. Besides, a voltage detecting element 8 and a specific gravity detecting element 9 provided for the battery 2 detect a terminal voltage and the specific gravity of an electrolyte respectively. When the terminal voltage and the specific gravity of the electrolyte lower to the set values respectively and the residual capacity of the battery obtained by the integration of the amount of charge or discharge is faulty, interrupt correction is executed so that the residual capacity be the value determined from the terminal voltage or the specific gravity of the electrolyte.

Patent
21 Sep 1989
TL;DR: In this paper, the authors present methods for analysing the state of charge of batteries, as well as the means allowing the said methods to be implemented, which is characterised essentially in that it consists in taking a precise and reliable measurement of the available capacity of the battery, by taking account of variations in its output.
Abstract: The present invention relates to methods for analysing the state of charge of batteries, as well as the means allowing the said methods to be implemented The method is characterised essentially in that it consists in taking a precise and reliable measurement of the available capacity of the battery, by taking account of variations in its output, as a function of the amplitude of the currents supplied and/or drawn, the sending, in discharge, of a first signal on approaching the allowable limiting discharge, then of a second signal at the said limit, the holding of the said first signal during the charge until the level of the capacity which gave rise to its sending, the sending, on charge, of a third signal at the moment the full charge appears, the continuous display of the available capacity, the memory storage of the parameters of its operation upon cutting off its power supply, and the indication of the degree of wear of elements of an electrical traction engine, by virtue of the combination with a totaliser means