Showing papers on "State of charge published in 1990"

Intelligent battery system

Abstract: An intelligent battery system senses current flowing in the direction of charge current through positive and negative terminals and battery cells of a battery pack. In response, a processor within the battery pack transmits battery parameter data to a separate output port of the battery pack. The battery parameter data includes the state of charge of the battery cells, temperature data and the type of battery pack. The processor also responds to specific data requests transmitted into the battery terminals by transmitting the requested battery parameter data. The battery pack is also designed to minimize power dissipation of the processor. When the battery pack is not subjected to either charge or discharge for a predetermined period, the processor is rendered into a "light-sleep" mode in which power dissipation is substantially reduced. The processor is awakened from the light-sleep either by a timer or by charge or discharge activity to monitor the amount of charge or discharge and other battery parameters.

Method and apparatus for measuring the voltage and charge of a battery

Abstract: Method and apparatus for measuring the voltage and state of charge of a secondary battery The voltage and state of charge values are taken by a circuit every four (4) seconds by reading voltage, waiting two (2) seconds, reading current, waiting two (2) seconds, and repeating the voltage readings and the current readings The circuit includes a 14-bit microprocessor, CMOS analog switches, and two operational amplifiers The voltage and current readings are taken from dual-sloped converters, and the values determined by software algorithms in the microprocessor

Apparatus and method for indicating state of charge of a battery

Abstract: A device for indicating the state of charge of an electrochemical cell or battery includes a regulated-voltage generating circuit having an input connectable to the cell and an output providing a regulated reference voltage, an amplifying circuit having an input connectable to the cell and an output having a predetermined relation to a voltage within a predetermined range applied to the input of the amplifying unit, and a solid state analog display unit having a reference input connected to the output of the regulated-voltage generating circuit and an address input connected to the amplifying circuit. The relation between the address voltage output of the amplifying circuit and the cell voltage input is such that the address voltage corresponds to the state of charge of the cell in the predetermined range of cell voltages and falls within the range of the most negative and most positive values of the reference voltage. The device is adaptable for use as an integral state of charge indicator for a battery-operated tool or appliance or as a charge tester for different sizes and types of consumer batteries. One such battery tester has a housing shell provided with a plurality of shaped recesses, each recess receiving a single type or size of battery for test. A number of recesses are aligned so that a single spring-biased metal contact strip can be used for the number of recesses. The spring backing for the contact strip is a resilient pad of plastic foam material.

Battery state of charge indicator

Abstract: A method for measuring and storing the state of charge of batteries, such as used in electric vehicles. The stored charge value is initially derived from the value of battery terminal voltage measured prior to connection of the battery to the load, e.g. the traction motor. While the battery is connected to the load, approximated state of charge values are periodically derived by adding a correction voltage, comprising the product of measured load current and of a predetermined value of internal resistance, to the measured terminal voltage of the battery. The stored and approximated state of charge values are periodically compared and the stored state of charge value is decremented by a predetermined increment in response to the stored charge value having exceeded the approximated state of charge value during each of a predetermined plurality consecutive comparisons.

Battery state of charge indicator

Abstract: In combination with an electric storage battery having a container and a cover, and having a plurality of walls for enclosing the electrolyte and other electrochemical components of the battery, a state of charge indicating device for monitoring the concentration of the electrolyte during the charge and discharge cycles of the battery. The indicating device is made of a porous solid support and an acid concentration sensitive dye which exhibits a change in color in accordance with the acid concentration of the electrolyte. The indicating device also includes a viewport located in one of the walls of the battery for viewing the color of the dye. The color may then be correlated to a reference scale to determine the state of charge of the battery.

Aircraft battery status monitor

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.

Sealed batteries in transient limiting distribution networks-methods of measuring their internal resistance

Abstract: As the internal resistance (R/sub i/) of a battery directly influences the battery voltage drop, R/sub i/ is regarded as a key parameter in the design of high-ohmic distribution systems with transient limitation. Different methods of R/sub i/ measurement supply different results, especially those obtained in different states of discharge. For the project engineering of high-ohmic distribution systems with transient limitation the method of R/sub i/ measurement with short circuit current limitation is decisive. The measurement method is recommended which provides the best results for a high-ohmic distribution with transient limitation, and the results are confirmed by measurements performed in the power supply circuit interrupted by a fuse. The dependence of internal resistance on the state of charge of the battery obtained by various methods is discussed. >

Charge state monitor for power source of electronic timepiece - has output voltage measurer connected to counter for lower and upper thresholds

Abstract: A circuit, for monitoring the state of charge of a battery source for clocks/watches which run independently of mains supply measures the output voltage of the source (Ua) via a metering module (1). A pulse generator (4), driving a counter (2), provides a timed interval of 24 hours during which the voltage (Ua) must be continuously below a threshold value before a warning signal unit (7) is activated. A second counter (6) triggers a signal unit (7) after 10 days as long term confirmation of battery exhaustion. Warning signals may be optical or acoustic. USE/ADVANTAGE - Prevents spurious triggering of first warning signal caused by transient voltage drops, e.g. stepping motor jamming. Gives user several days forewarning before battery is in totally unserviceable state. Applicable to either analogue or digital display.

Method and apparatus for indicating state of charge of a battery

Abstract: The disclosure relates to an analog solid state display device for presenting an analog display of the state of charge and voltage of a battery, typically a rechargeable battery. There is disclosed an apparatus for deriving a signal which is a function of the state of charge of the battery to drive an analog solid state indicating display by such signal. The analog solid state indicating display can comprise an analog liquid crystal display of the voltage and state of charge of a battery to which the display is connected. In addition, there is disclosed a circuit for driving an analog liquid crystal display of the state of charge of the battery with the analog liquid display being disposed within the housing of a tool or appliance which contains the battery. The disclosure also relates to the indication of the state of charge of a battery by an analog liquid crystal display when the battery is under load. The display can comprise an analog bar graph presentation. The disclosure also pertains to an analog liquid crystal display to indicate both the state of charge of a battery and the rate of change of the state of charge of the battery. There is also disclosed a method of indicating the state of charge of a rechargeable battery which includes the steps of amplifying the output of the battery of which the charge is to be indicated while the battery is under load, subjecting the range of amplified outputs extending from a fully discharged condition to a fully charged condition of the battery to a predetermined electrical function, and applying the output which has been subjected to the predetermined electrical function to a display device in which the size, extent, or position of the display portion indicates the charge level and the state of charge of the battery.

Procedure for determining the state of charge of an accumulator

Abstract: The present invention relates to a method for determining the state of charge of an accumulator in that, starting from a defined state of charge of the accumulator, a charging-up and a discharging process occurs with in each case a particular current in one cycle, the cycle being ended when the defined state of charge has been reached again and the state of charge of the accumulator being inferred from the difference of the periods needed for the charging-up and the discharge process. Alternatively, a discharge can be carried out from a defined state of charge of the accumulator in order to determine the available capacity from the charge removed.

Device for making the charging voltage of a vehicle power supply system symmetrical

Abstract: The proposal is for a device for making the charging voltage of a vehicle power supply system symmetrical in which two batteries providing said power supply are charged in such a way that the one in a lower state of charge is given priority during charging. Here, the voltage is regulated in the prior art manner by switching the generator exciting current on and off. An additional circuit detects the current state of charge of the batteries and at the same time ensures that the one with the lower charge is given priority.

State-of-charge indicators for aqueous primary batteries-a review

Abstract: State-of-charge indicators are very necessary when using batteries in critical applications. Primary batteries with aqueous electrolytes are discussed. In the past, various methods have been attempted to indicate the charge remaining in a battery. They include open circuit voltage, voltage/current transients, impedance, density of electrolyte, coulometer, phase angle, etc. The fundamental aspects of the various methods are discussed. >

Apparatus for monitoring the state of an electrical energy source

Abstract: An apparatus for monitoring the state of charge of a battery having a shunt resistor (14) connected in series with a battery (10) and an integrating circuit (30) connected across the terminals of the shunt resistor (14) is provided. The integrating circuit (30) includes a Memoriode (36) having a large capacitance and the capability to store charge for long periods of time, so that the integration can be performed along the same curve even if power to the integrating circuit is interrupted.