Abstract: A testing device applies time-varying electrical excitation to a cell or battery and senses the resulting time-varying electrical response. Computation circuitry within the device uses voltage and current signals derived from the excitation and response signals as inputs and computes values of elements of an equivalent circuit representation of the cell or battery. The internal temperature of the cell or battery is calculated from the value of the time constant of a particular parallel G-C subcircuit of the equivalent circuit. The battery's internal temperature is then either displayed to the user, used to apply appropriate temperature corrections to other computed quantities, used to detect thermal runaway, and/or used to control an external process such as charging of the battery.

Abstract: For use with a valve regulated lead acid (VRLA) battery, a fluid fill system and a method of maintaining fill fluid in a VRLA battery. In one embodiment, the system includes: (1) a fluid determination circuit, associated with the battery, that determines a quantity of fill fluid in the VRLA battery and (2) a controller, coupled to the fluid determination circuit, that introduces replacement fill fluid into the VRLA battery based on the quantity to replace fill fluid lost from the VRLA battery. The fluid determination circuit comprises sensors that measure a temperature and pressure associated with the VRLA battery, and a state of a fluid release valve on the battery.

Abstract: A battery tub tester is disclosed that tests the individual batteries, battery accessories and connections as they are being assembled into a battery tub for an electric vehicle. The batteries and battery tub accessories, including temperature sensing devices and battery monitor modules, are mounted and electrically connected in the battery tub in accordance with a known battery tub assembly scheme. As the assembler mounts and connects the batteries and battery tub accessories, the tub tester determines the battery voltages of each battery after it is mounted and connected within the tub to determine if the batteries have the desirable voltage and will operate as they are intended and are connected properly. Additionally, the tester determines the temperature readings as the temperature sensors are being mounted, to determine if the temperature sensors will operate as intended and are connected properly.

Abstract: A device (10) and method for charging rechargeable type batteries (11) in which the charging current (Ib) supplied the batteries is measured and the temperature variation (.DELTA.Teff) of the batteries is determined over an established interval of time. Furthermore, this variation is compared with a reference value (.DELTA.Tref) so that battery charging can be interrupted when the variation equals or exceeds the reference value (.DELTA.Tref). The reference value (.DELTA.Tref) is defined in relation to the current (Ib) charging the batteries (11) so as to take into account all the possible current values with which the batteries are charged. To advantage, battery charging is interrupted and battery overloading avoided when the charging of the batteries (11) is terminated by a very low charging current. The device (10) and method are particularly suitable for charging the batteries of electronic equipment, such as a personal computer or similar.

Abstract: A battery charging method in an environment of variable temperatures provides for a temperature correction to determine an onset of an overcharge phase which is detected by a discernible thermal energy output of a charging battery. The method comprises a precursory operation of determining time period required for effecting a temperature change in the battery in response to a temperature change of an ambient space about the battery. The temperature of the battery is then monitored throughout the charging process by measuring the temperature of the battery at timed, predetermined intervals. Over the same timed intervals the temperature of the ambience is measured. A measured difference in the temperature of the ambience with respect to a prior temperature of the ambience is applied to a measured temperature of the battery as modified by a predetermined time delay factor.

Abstract: This invention makes it possible to inform a user of a battery replacement timing and a necessity for maintenance by storing in advance a reference vale of average battery temperature rise speed, obtaining an actual value of average battery temperature rise speed by measuring the battery temperature during charging, determining the battery deterioration easily, reliably, and irrespective of ambient temperatures at which the battery is charged and discharged by comparing the actual value of average battery temperature rise speed with the reference vale of average battery temperature rise speed.

Abstract: A battery remaining capacity measuring apparatus comprises a temperature sensor 5 and a remaining capacity operation portion 19. A temperature sensor 5 detects a temperature of a battery 3. A remaining capacity operation portion 19, wherein when a detected temperature of a battery 3 from a temperature sensor 5 is not within the range of a predetermined temperature in the state of an open circuit, a load 1 and a battery 3 which are previously obtained according to a detected temperature correct a line pattern in the state of an open circuit and when a load is connected to a battery, a remaining capacity can be obtained on the corrected line. Accordingly, it is possible to obtain a remaining capacity according to this temperature, even if a temperature of a battery 3 is not within the range of a predetermined temperature.

Abstract: A temperature compensation module for use with battery charger/rectifier units. The compensation module is used to vary the battery charger output voltage as a function of temperature. This is done by controlling the series impedance of the charger's voltage sense leads. The impedance is controlled to produce a voltage offset in series with the sense leads. Thus, the charger's output voltage is equal to its adjusted output voltage plus the offset voltage.

Abstract: A battery tester is formed at an AC constant-current generator for applying an AC current for measurement to a battery BT under test via a coupling capacitor, an internal resistance detecting device for detecting the internal resistance of the battery BT according to a voltage signal therefrom when the AC current is applied, a voltage detecting device for detecting the terminal voltage across the battery, and a deterioration judging unit for judging the deterioration of the battery from the internal resistance and terminal voltage detected by the internal resistance detecting device and the voltage detecting device. The internal resistance and terminal voltage of the battery are measured simultaneously, and deterioration of the battery is judged from the measurement data.

Abstract: A voltage detector is described herein which eliminates an entire operational amplifier or comparator from conventional voltage detectors. In one embodiment of such a voltage detector, a band gap reference generator is connected so as not to incorporate any feedback mechanism and where an off balance in the band gap reference generator is used to detect whether an input voltage falls below a threshold voltage. By eliminating the feedback path in the band gap reference generator, a comparator is eliminated. Other types of voltage detectors which provide a highly stable operation over a wide range of temperatures are described.

Abstract: A battery remaining capacity measuring apparatus including a remaining capacity operation portion 3 for collecting a voltage of a battery 3 and a current passing through a load until an accelerator is on when turning an accelerator on and once turning an accelerator off after starting an ignition, obtaining a line from 2 points having a strongest relationship between the voltage and the current, and displaying an initial remaining capacity according to this line and a reference value.

Abstract: A battery remaining capacity measuring system for an electric motor vehicle in which current data and voltage data are sampled at an interval of 1 ms so that a plurality of current data and a plurality of voltage data are averaged at an interval of 100 ms, respectively, to obtain sets of average current data and average voltage data which in turn, are collected and plotted on a current-voltage-axis coordinate. In addition, the current-voltage-axis coordinate is divided into a plurality of zones, and when an in-zone quantity decision section decides that the number of sets of average current data and average voltage data exceeds a given value in all the zones, a correlation coefficient decision section decides a coefficient of correlation between current and voltage. When the coefficient of correlation shows a high correlation, an approximate straight line calculating section calculates an approximate straight line, while a remaining capacity calculating section calculates and displays a remaining capacity.

Abstract: While a power source is being supplied from a sub-battery by a voltage-current change trend calculating section, the voltage-current change trend calculating section collects currents from a battery and terminal voltages. A voltage-current approximate straight line calculating section obtains an approximately linear function, and a battery residual capacity calculating section obtains a residual capacity voltage based upon the approximately linear function and open-circuit voltages. A current storage stop discriminating section integrates the currents while the residual capacity voltage is lower than a previous residual capacity voltage, and when supplying from the sub-battery is stopped, obtains total capacity according to the open-circuit voltages at the stop and supplying and according to the integrated currents.

Abstract: A power management system automatically manages the power to operate a biomedical device, such as an infusion pump containing an internal battery. When external power is available, the management system operates the biomedical device from the external power and controls a recharger to maintain the battery at full charge. The power management system automatically calculates battery charge status and use and provides a run time display of the calculated amount of time that the battery can operate the biomedical device under current power requirements of the biomedical device. The power management system automatically updates the calculated charge status of the battery as well as the calculated capacity of the battery based on environmental factors and battery characteristics. The power management system automatically and periodically performs a deep discharge/recharge cycle to refresh the battery.

Abstract: Detected values of a voltage and a current of a battery which are supplied from a voltage and current detector are stored in a memory at a plurality of times while the battery is being discharged. A regression line calculator determines an internal resistance and an open-circuit voltage (non-load voltage or electromotive force) of the battery based on the detected values stored in the memory. Even when the battery is in use with the voltage and the current frequency varying while it is being discharged, a memory effect on the battery can be determined from a reduction in the open-circuit voltage and a deterioration of the battery can be determined from an increase in the internal resistance.

Abstract: The present invention relates to a method of measuring residual capacity of a Ni/MH (nickel/metal hydride) cell by measuring the change in the electrical resistivity of a Ni/MH cell according to the change of the concentration of hydrogen in metal hydride. According to the present invention, a method for measuring residual capacity of a Ni/MH cell comprises the steps of measuring electrical resistivity of a first Ni/MH cell, and determining the residual capacity of the first Ni/MH cell (i) from a predetermined data of n-pairs of electrical resistivity values and residual capacity values of a second Ni/MH cell which has substantially the same composition as the composition of the first Ni/MH cell, or (ii) based on a predetermined functional relationship between the electrical resistivity and residual capacity of the second Ni/MH cell.

Abstract: In a method of detecting deterioration of a battery pack consisting of a series assembly of a plurality of battery modules during charging, on the basis of a voltage difference between a plurality of battery modules, deterioration detection is inhibited until a predetermined capacity is charged after starting of the charge. Also, in a detection apparatus for deterioration in a battery pack according to the present invention, a deterioration reference discharge voltage value which should correspond to a discharge current value and a temperature value is calculated on the basis of reference data, and the deterioration reference discharge voltage value is compared with an actual discharge voltage value to judge whether deterioration occurs or not.

Abstract: An automatic monitoring system of storage batteries housed at an application site which includes an A.C. power source at the site, a mechanism to interrupt the A.C. power from its source and generate an alarm, a battery plant to provide D.C. power when the A.C. power is interrupted, a mechanism to automatically detect and measure the voltages generated from said battery plant, a mechanism to measure the midpoint of the D.C. battery discharge voltage by measuring the rate of change of said voltage over time and halving the difference between plateau and end of life voltages, a mechanism to generate an alarm message (a) if said midpoint has been reached, (b) if a predetermined low battery cutoff voltage has been reached, (c) if the battery plant is being overcharged or undercharged, and/or (d) if A.C. power is interrupted.

Abstract: A battery monitor for monitoring the voltage and temperature of the batteries associated with a battery pack of an electric vehicle. The battery monitor includes an opto-isolator that electrically separates an isolated portion of the battery monitor connected to the batteries from a non-isolated portion of the battery monitor that transmits battery voltage and temperature signals to a vehicle controller of the electric vehicle. The battery monitor is positioned proximate to a battery tub holding the batteries of the electric vehicle so that high voltage wires connected to the batteries within the battery tub are limited in length for safety purposes. Further, a limited number of wires transmitting the battery voltage and battery temperature signals from the battery monitor to the vehicle controller are required.

Abstract: The present invention provides an aqueous gel comprising a polymer of (meth)acrylamide or particular (meth)acrylamide derivative(s), particulate metal oxide(s) and an aqueous medium, a process for producing said gel, and products utilizing said gel.This aqueous gel can be produced so as to have transparency, has fire resistance and can prevent the spreading of flames, and is highly elastic. The aqueous gel, when produced as a transparent gel, becomes cloudy when heated or cooled and is useful for the shielding of heat rays or cold radiation.

Abstract: A method is specified for determining the charge state of a battery, for example a vehicle starter battery, in which a charge balance is carried out by evaluating the charging current and the discharging current. This charge balance is checked with the aid of the measured battery open-circuit voltage and corrected. Depending on further variables, for example, the battery temperature, a time interval is determined which can be used to detect how long the battery can still supply an acceptable discharging current under the given conditions. This time interval is optimized with the aid of suitable correction functions, and serves as a measure of the present charge state of the battery.

Abstract: A battery monitor system for monitoring the residual capacity of a battery has a controller for determining the residual capacity of a battery, detecting the output electric power of the battery when the battery is being discharged, and correcting the residual capacity depending on the output electric power such that as the output electric power of the battery increases, a new residual capacity produced when the residual capacity is corrected decreases. The residual capacity may be corrected by subtracting a residual capacity corrective value, which increases as the output electric power of the battery increases, from the residual capacity. The residual capacity of the battery can accurately be determined and monitored depending on the output electric power from the battery.

Abstract: A method and a device for determining the battery discharge characteristics and estimating the remaining battery capacity easily by a simple mechanism even if time elapses. A discharge characteristics calculation section reads voltage, current, and temperature from a voltage sensor, a current sensor, and a temperature sensor, respectively, and determines the approximated discharge characteristics at a given time based on a position relationship of the discharge characteristics curved surface function V=a.multidot.log(H.sub.0 -H)+b.multidot.H+c to voltage-temperature-duration of discharge axes. A duration of discharge characteristics calculation section determines the duration of discharge from a fully charged state to the present based on the approximated discharge characteristics. A remaining capacity calculation section determines the remaining capacity based on the approximated discharge characteristics.

Abstract: A process is disclosed for evaluating the remaining charge in an accumulator battery by determining the residual charge at the start of discharge, adding up the quantities of energy extracted as and when the battery is used, determining the quantities of charge which are not restorable instantaneously because of a high discharge rate, charge which is restorable by relaxation of the battery and charge which is not restorable under the influence of temperature.

Abstract: A battery detect circuit (32) is connected to a battery, with the current A battery V:the battery and the current extracted from the battery measured with a sense resistor (50) and convened to charge and discharge voltages with a V/F converter (52). A microcontroller (64) is operable to increment a nominal available charge (NAC) register (180) during a charge operation and to increment a discharge rate counter (DCR) (184) during a discharge operation. The NAC register (180) indicates the available charge, i.e. the charge state of the battery, which value is output to a display (34). The display (34) is controlled to operate in either an absolute full mode or a relative full mode. This is determined by an external programming pin which has first and second programming states associated with the two modes.

Abstract: An apparatus and method for monitoring the state of charge of the battery having a shunt resistor connected in series with a battery and an integrating circuit connected across the terminals of the shunt resistor which includes a large capacitance element having 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 during continuous or intermittent use. The apparatus and method are applicable to batteries for automotive vehicles. Temperature compensation schemes to adjust the state of charge monitoring circuit to correct for changes in battery performance characteristics with temperature are provided. A circuit for detecting the existence of a defective battery cell is provided. A system for monitoring charging and discharging of the battery over time and identifying various battery conditions and potential battery or battery charging system failures is provided.

Abstract: A remaining capacity estimating system and method for an automobile battery capable of estimating and displaying an accurate remaining battery capacity by calculating an internal resistance value of the battery based on a terminal voltage in a disconnected state to electrical loads, a terminal voltage in a selectively connected state to an electrical load and a discharge current value in this connected state, then obtaining a remaining battery capacity at the present temperature condition from a map showing a relationship among a remaining battery capacity, a discharge current and an internal resistance, and finally transforming the obtained remaining battery capacity into a remaining battery capacity at a standard temperature condition.

Abstract: A battery monitoring system (10) supplies the user of a battery power system with information indicating the capacity remaining in the battery (9) during discharge. During discharge the system (10) monitors various parameters and calculates on a rapid sampling basis derived parameters from algorithms stored in memory in tabulated form. The recharging efficiency is also evaluated, stored and updated on each charge/discharge cycle so that ageing of the battery (9) is monitored.

Abstract: Method and apparatus for accurately determining the charge state of a battery is disclosed. The charge state is derived from the battery voltage, which is corrected for errors introduced by temperature and series resistance. Error from series resistance is minimized by either making an open circuit voltage measurement, or by making a plurality of voltage measurements under known load conditions, calculating the series resistance from these measurements, and calculating an equivalent open circuit voltage, compensating for the voltage drop caused by the series resistance of the battery. Errors introduced by temperature induced shifts in battery voltage are corrected by reading the battery temperature and correcting the battery voltage to a reference temperature. The battery voltage corrected for temperature and series resistance effects is used to compute charge state by table look up or algebraically.

Abstract: A charge monitor for a battery operated computer includes a processor electrically connected to a plurality of signal generating circuits. The generated signals represent the temperature, voltage and current characteristics of the battery being monitored. The level of remaining battery energy is ascertained by utilizing a predetermined discharge table which is dependent upon the battery temperature, voltage and current.

Abstract: A battery monitor which monitors the operating parameters of a battery to provide an indication of, for example, the absolute state of charge, the relative state of charge, and the capacity of the battery under battery discharge, rest, and recharge conditions. The battery monitor includes a current sensor for sensing battery current, a voltage sensor for sensing battery voltage, and a temperature sensor for sensing battery temperature. A processor approximates to a high level of accuracy the battery parameters utilizing an iterative process based upon predetermined relationships, employing empirically determined constants and parameters determined in the immediately proceeding iteration stored in memory. Output signals indicative of the determined parameters are provided and may be utilized for many different battery applications.

Abstract: A stationary battery testing device as provided for measuring imminent battery failure while the battery is in a float mode. The device includes a circuitry for measuring the internal resistance changes of a battery and then comparing them over a predetermined duration of time so as to provide audible or visual discernable signals to indicate an imminent battery failure after the expiration of said predetermined period of time. An additional temperature monitoring component may be provided for the device to monitor internal changes within the battery with respect to temperature. This can also be combined in a temperature compensated automatic adjustment of voltage and alarm thresholds in an active feedback loop to augment and broaden the basis of stationary battery applications where the battery testing device can be used.

Abstract: A battery condition detection apparatus comprises at least the first two of a battery discharge current detector, a battery terminal voltage detector, and a battery electrolyte concentration signal detector. The battery condition detection apparatus further comprises a memory circuit for storing detection signals generated by at least the first two detectors and inputted to the battery condition detection apparatus, and a computation device for executing computation processing on output signals from the aforesaid detectors.With the foregoing structure, the battery condition detection apparatus performs computation to obtain at least one of corrected values of the battery terminal voltage and the battery electrolyte concentration in the state where the battery discharge current assumes a predetermined value, and performs the detection of the battery condition and/or the control of power generation of a battery-charging generator.

Abstract: A system is provided for temperature compensating and monitoring the energy f a lithium battery. In this method, a temperature compensation factor is determined according to a value of temperature. A determination is made of the energy usage while the battery operates at that temperature. The temperature usage is then compensated in accordance with the temperature compensation factor. A second temperature, along with a second temperature compensation factor, is determined. A second energy level is determined and compensated as described for the first. A cumulative energy usage is determined according to the first and second compensated energy usage values.

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.

Abstract: A voltage potential monitoring circuit is operative to set a voltage potential threshold substantially independent of ambient temperature variation. The monitoring circuit includes a first circuit for generating a first current proportional to the voltage potential being monitored, and a second circuit responsive to the first circuit for generating a second current. The voltage potential threshold is set substantially as a function of the first and second currents. The monitoring circuit further includes a circuit responsive to the first and second currents for generating an undervoltage signal when the monitored voltage potential falls below the set voltage potential threshold. The voltage potential monitoring circuit has application in an electronic device which is operational over an ambient temperature range and includes a source of power for generating a voltage potential suitable for energizing the electronic device.

Abstract: The present invention is an apparatus and a method for determining the state of charge of a rechargeable battery. It comprises a means for charging the batter, current sensors, heat detectors for detecting the heat emanating from the battery during charging, with the heat being the complement of the charge acceptance percentage, and a processor for storing a mathematical charge acceptance model for providing the relationship between the charge acceptance percentage and the state of charge of the battery, and for calculating the state of charge of the battery from the heat detected by the heat detectors and the charge acceptance model. An accurate measure of battery charge state is produced while the battery is being charged. This provides information concerning the operability of the battery and also allows efficient charging to avoid energy waste.

Abstract: A method of determining the state of charge of a motor vehicle battery 1 in which a stabilization load 2 is applied to the battery 1 after the engine is switched off to accelerate the stabilization of the charge distribution within the battery 1. The stabilization load 2 is applied until the terminal voltage of the battery 1 reaches a level corresponding to a predicted value of the state of charge of the battery 1. After a pre-determined delay of 8 hours or less, the terminal voltage of the battery 1 is measured and the state of charge derived therefrom.

Abstract: A device for indicating changes in the state of charge of a rechargeable battery including a current sensor to sense current flow into and out of the battery and to provide an output indicative of both the magnitude and direction of the current flow, a timer to provide a timing signal, and a computer programmed to compute from the output of the current sensor and the timer, a signal representative of the charge dissipated from or accumulated in the battery over a period of time. Preferably the device includes data storage to store an indicatioin of the state of charge of the battery and the computer is programmed to use the signal to update the stored data to provide an indication of the current state of charge of the battery.

Abstract: A battery state monitoring apparatus determines the remaining life of a battery, which is used by being repeatedly charged and discharged, upon taking into account the charging/discharging characteristic of the battery and the surrounding temperature, thereby making it possible to ascertain the remaining life of the battery in accurate fashion. The apparatus includes a voltage measuring unit for measuring terminal voltage of a battery, a current measuring unit for measuring charging and discharging current of the battery, a temperature measuring unit for measuring temperature of the battery, an arithmetic unit to which measurement values outputted by the voltage measuring unit, current measuring unit and temperature measuring unit are applied for computing remaining life of the battery, and a remaining life display unit for displaying the remaining life of the battery computed by the arithmetic unit.

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.

Abstract: The discharge capacity of a secondary battery, e.g. a Ni-Cd battery, has a maximum value at room temperature and gradually decreases both with an increase and decrease of ambient temperature. The battery discharge capacity also varies inversely with the number of battery charge/discharge cycles of the battery. A circuit for measuring the remaining discharge capacity of the secondary battery comprises a capacitor (23) whose temperature and age-variation characteristics are very similar to those of the discharge capacity of the secondary battery. The current flowing through the battery and motor (13) is detected by a series resistor (17). A voltage follower (20) responds to the detected voltage and drives a resistor (24), so that capacitor (23) is discharged at a rate determined by the resistor (24) current. The capacitor voltage is compared with a predetermined value by a hysteresis comparator (29) which controls the ON/OFF state of a transistor (21) in accordance with the comparison.

Abstract: In an arrangement for use in an electronic circuit controllably put into operation by a battery and for indicating a consumption status of the battery, a measuring circuit measures a total time interval of operation of the electronic circuit. A processing circuit processes the total time interval into a calculated status for the battery. An indicator indicates the consumption status based on the calculated status. The processing circuit may comprise a memory for memorizing various current rates which are used in the electronic circuit and on which an arithmetic circuit calculates the calculated status. Alternatively, first and second measuring circuits may be used with first and second current rates memorized in the memory for the first and the second measuring circuits. Instead of the measuring circuits, a summing circuit may be supplied with a succession of the current rates repeatedly read out of the memory to sum up a total amount of current consumed by the electric circuit.

Abstract: A battery check device for a camera which is capable of accurately making a battery check without being affected by temperature comprises detecting means for detecting the service condition of a battery; comparison means for comparing the detection value obtained by the service condition detecting means with a reference value; informing means for informing the photographer of the service capacity of the battery in response to the output of the comparison means; and changing means for changing the reference value to change thereby the informing state of the informing means according to temperature.

Abstract: An improved self-contained electronic device for testing storage batteries and other dc sources is disclosed. The testing device accurately performs small-signal measurements of the battery's dynamic conductance and provides for displaying either a numerical reading proportional to the battery's available power, or a qualitative assessment of the battery's condition. Special design features permit powering all active circuit elements by means of common power terminals and allow circuit implementation with medium scale integrated (MSI) circuits.

Abstract: A vehicular charging system is provided with a microcomputer for performing a diagnostic routine on the vehicle battery and charging system. The battery charging condition and internal resistance are monitored to determine the service life of the battery and the state of the battery charging system. The internal resistance is calculated by taking the difference between the voltage when the battery terminals are in an open circuit condition and the voltage when the battery terminals are in a closed circuit state and dividing this difference by the battery current. Also included in the charge condition measurement is the measurement of the specific gravity of the battery.

Abstract: This invention relates to a device which when connected to a storage battery of a type which is a prime power source, such as a lead acid storage battery, measures the open circuit voltage condition of the battery to give a reading in increments of time of the remaining useful life of the battery for a given use up to the point of full discharge of the battery.

Abstract: Deflection unit (5) in which field-conducting elements (9,10) are provided between the field deflection coil (8) and the line deflection coil (7) so that a good level of astigmatism as well as an acceptably small coma error and a reduced EW frame distortion are obtained. In order to prevent that the field-conducting elements (9,10) from having a detrimental influence on the ten-pole field generated by the field deflection coil (8), each of the said elements is formed as a slightly curved plate having a central portion (15) on which two limbs (17,19) extending substantially transversely to the axis (Z) of the annular member (6) are formed.

Abstract: A method of computing the state of charge for a battery including the steps of sensing the battery voltage and current, and computing the used battery capacity, C.sub.u, and the average battery current, I. The total battery capacity, C.sub.t is calculated from average current using the Peukert equation. The state of charge is calculated as a function of C.sub.u /C.sub.t to account for temperature and aging effects, recuperation effects, regeneration effects, and current variation effects.

Abstract: State of charge is determined for a battery during a quiescent interval with substantially no current flow through the battery by determining the quiescent time interval since the last substantial current flow through the battery, taking a rapid measurement of the battery terminal voltage, and relating the combination of these two measurements to known battery open circuit voltage recovery characteristics.