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Showing papers on "State of charge published in 1979"


Journal ArticleDOI
TL;DR: In this paper, real space renormalization group and Monte Carlo techniques are used to study the statistical mechanics of a lattice gas model of Li ordering in an intercalation battery, and the dependence of the voltage on the state of charge of the battery is related to the number and types of sites available to the Li ions and to the strength and distance dependence of Li-Li interaction.

99 citations


Patent
28 Sep 1979
TL;DR: An electrically heated hair curling iron includes a sheet-shaped heater with electrodes affixed to an electrically resistive layer, wrapped around an elongated cylindrical support, and capable of being rapidly heated and maintained hot by electric current available from a rechargeable storage battery as mentioned in this paper.
Abstract: An electrically heated hair curling iron includes a sheet-shaped heater with electrodes affixed to an electrically resistive layer, wrapped around an elongated cylindrical support, and capable of being rapidly heated and maintained hot by electric current available from a rechargeable storage battery. The resistive layer has a positive temperature coefficient of resistance so that its temperature is self limiting. The storage battery is contained in a handle attached to the cylindrical support, and a battery charger is disclosed which comes into electrical contact with the battery when the handle is inserted in a cavity located in the battery charger. An elongated longitudinal clip is used to retain the hair in contact with the heater; a removable cap protects the heater and clip when the iron is not in use, and also engages a switch which ensures that the iron does not remain on. The charger and the curling iron are each provided with an LED to indicate operation of the charger and state of charge of the battery, respectively.

91 citations


Patent
05 Oct 1979
TL;DR: In this paper, an aleatory source of energy, e.g., a battery of photocells, supplies energy to a load (5) and to a storage battery (3).
Abstract: An aleatory source of energy, e.g., a battery of photocells (1), supplies energy to a load (5) and to a storage battery (3). When the source is supplying more energy than is being drawn by the load, the storage battery is charged; when the source is supplying less than the demand, the shortfall is made up by drawing energy from the storage battery. The state of charge of the storage battery is monitored by a meter (8) which governs a regulator (7). Once the battery is charged to a predetermined threshold, the amount of current it draws from the source is regulated, and energy supplied by the source in excess of the combined requirements of the load and of battery charging is diverted to a storage means (6) other than the storage battery (e.g., a mains electricity supply grid). The flows of energy to both the battery and the other storage means are controlled by the regulator (7) as a function of the state of charge of the battery.

69 citations


Journal ArticleDOI
TL;DR: In this paper, the problem of non-destructive determination of the state of charge of nickel-cadmium batteries has been examined experimentally and theoretically from the viewpoint of internal impedance, and it is shown that the modulus of the impedance is mainly controlled by diffusion at all states of charge.
Abstract: The problem of nondestructive determination of the state-of-charge of nickel-cadmium batteries has been examined experimentally as well as theoretically from the viewpoint of internal impedance. It is shown that the modulus of the impedance is mainly controlled by diffusion at all states of charge. Even so, a prediction of the state of charge is possible if the equivalent series/parallel capacitance or the alternating current phase shift is measured at a sufficiently low a.c. test frequency (5–30 Hz) which also avoids inductive effects. These results are explained on the basis of a uniform transmission-line analog equivalent circuit for the battery electrodes.

69 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that the internal impedance of a lead-acid battery is controlled by charge transfer and diffusion processes in the frequency range 15-100 Hz. But this was based on a uniform transmission line analog equivalent circuit for the battery electrodes.
Abstract: The determination of the state-of-charge of the lead-acid battery has been examined from the viewpoint of internal impedance. It is shown that the impedance is controlled by charge transfer and to a smaller extent by diffusion processes in the frequency range 15–100 Hz. The equivalent series/parallel capacitance as well as the a.c. phase-shift show a parabolic dependence upon the state-of-charge, with a maximum or minimum at 50% charge. These results are explained on the basis of a uniform transmission-line analog equivalent circuit for the battery electrodes.

46 citations


Patent
Pierre Belot1
28 Nov 1979
TL;DR: In this article, the state of charge of a storage battery is monitored by providing a magnitude g (e.g. a frequency F 1) which is proportional to the storage battery charging or discharge current I (sensed at 2).
Abstract: Monitoring the state of charge consists of providing a magnitude g (e.g. a frequency F1) which is proportional to the storage battery charging or discharge current I (sensed at 2) and of algebraically integrating said magnitude (e.g. in an up/down counter K4, K5) into data which is the image of the state of charge of the storage battery; the proportionality constant a=g/I between said magnitude and said current being given a lower value during charging than during discharging, and the value of the constant a being varied during charging as an increasing function of the current I.

31 citations


Patent
30 Nov 1979
TL;DR: A charge and discharge control circuit for portable accumulator sets is described in this article, which is based on maintaining a constant charge rate dependent on the measured discharge time, which is measured by reference to a pulse generating clock source followed by a programmable divider.
Abstract: A charge and discharge control circuits is for accumulator banks esp portable accumulator sets subject to repeated charge and discharge cycles Control is based on maintaining a constant charge and discharge rate dependent on the measured discharge time This is measured by reference to a pulse generating clock source followed by a programmable divider A decoder is fed with state of charge data and directly controls the charge switching circuit A luminescent diode driven from a logic controlled transistor provides indication of the end of charge, a similar diode signals the point when the battery is more than half charged

9 citations