Abstract: A battery charger includes a power source for supplying a primary charge current to a first battery, and a charge manager for charging a second battery. The charge manager is coupled to the power source and is configured to charge the second battery with a secondary charge current in accordance with a continuous comparison between a predefined maximum current limit and a total current drawn from the power source.

Abstract: An invention is provided for detecting polarization in a battery during battery charging. The invention includes applying a waveform to a battery, and obtaining a plurality of battery response voltage readings corresponding to points along the applied waveform. A battery response voltage curve is calculated based on the voltage differences between the plurality of battery response voltage readings. A battery polarization point is then identified when the slope of the battery response voltage curve stops increasing at an increasing rate. To enhance accuracy, a plurality of battery response voltage curves can be calculated, each based on voltage differences between battery response voltage readings taken along the waveform. The battery polarization point can then be identified when the slopes of all the battery response voltage curves stop increasing at an increasing rate.

Abstract: A diagnosis method for SOH of batteries includes the steps of: providing data of discharge voltages and currents of a battery unit; setting an acceptable value of a predetermined period of time and an acceptable range of variation rate of discharge current for the battery unit; calculating variation rates of discharge voltages and currents of the battery unit within the predetermined period of time by using the data of discharge voltages and currents; recording the data of discharge voltages and currents of the batteries and variation rates thereof; comparing the data of discharge voltages of the batteries and the variation rates thereof if the variation rates of discharge current are fallen within the acceptable range of current variation with selected reference data; and converting results of compared data of discharge voltages of the battery unit and the variation rates thereof into a SOH index.

Abstract: A battery charger for charging a battery through controlling a charging regulation circuit is provided. The battery charger includes a constant voltage mode controller, a current sensing unit, and a reference voltage generator. The constant voltage mode controller is for comparing a battery voltage of the battery with a first reference voltage to generate a regulation signal, and utilizing the regulation signal to control the charging regulation circuit to regulate a charging current applied to the battery. The current sensing unit is for monitoring the charging current to generate an error signal. The reference voltage generator is for setting the first reference voltage according to the error signal. By adding a voltage generator to the battery charger, the overshoot charging current will be reduced and the mode transition will become smooth.

Abstract: A method of determining the state of charge (SOC) of a rechargeable battery, the method comprising charging the battery using a substantially constant charge current; measuring the battery temperature; and conducting a first measurement of the battery voltage at a time interval, t1, from the start of the charging, and a second measurement of the battery voltage at a time interval, t2, from the first measurement.

Abstract: A charging method and a system for adjusting a charging current are provided. A charge capacity and a charge current rate of a rechargeable battery are read for adjusting an output current of a battery charger. As a result, the output current of the battery charger can be adjusted according to the decrease of the charge capacity of the rechargeable battery, thereby achieving the purpose of elongating the service life of the rechargeable battery.

Abstract: A method and integrated circuit for preserving a battery's charge and protecting electrical devices is disclosed. A maximum and a minimum battery voltage value at the output port are stored in a memory. A steady state battery voltage at the output port is measured and stored in the memory. A processor compares the measured steady battery voltage value to the maximum and the minimum battery voltage values. If the measured steady state battery voltage value is greater than the maximum battery voltage value, an over voltage state is reported by the processor. If the measured steady state battery voltage value is less than the minimum battery voltage value, a low battery voltage state is reported by the processor.

Abstract: In a method of reflow soldering, a non-aqueous electrolyte secondary battery is discharged to a first discharge voltage different from a second discharge voltage at an inflection point in a discharge curve of the non-aqueous electrolyte secondary battery having an axis of abscissa representing discharge capacity and an axis of ordinate representing discharge voltage. The discharged non-aqueous electrolyte secondary battery is placed on a substrate which is then exposed to a reflow soldering temperature to reflow solder the non-aqueous secondary battery to the substrate. The first discharge voltage is higher than the second discharge voltage to prevent degradation of characteristics of the non-aqueous electrolyte secondary battery resulting from decomposition of the non-aqueous electrolyte due to reaction of the non-aqueous electrolyte with excessive lithium ions in the cathode active material when the non-aqueous electrolyte secondary battery is exposed to the reflow soldering temperature.

Abstract: A battery control module for a rechargeable battery includes a voltage measuring module that measures a voltage of the rechargeable battery and that estimates a first derivative of the voltage with respect to time (dV/dt) and a second derivative of the voltage with respect to time (d2V/dt2). A charge control module estimates a maximum charging current based on dV/dt. A current control module limits a charging current of the rechargeable battery to the maximum charging current and turns off the charging current when d2V/dt2 is greater than dV/dt.

Abstract: A maximum power point tracking method, applied to a tracking device, employs a DC/DC converter connecting with a solar cell array, and including a controller actuating the DC/DC converter to perform an active resistance characteristic; a maximum power point tracking circuit adjusting the active resistance of the DC/DC converter; monitoring a change of an output power of the solar cell array in determining a direction for adjusting the active resistance of the DC/DC converter; and the maximum power point tracking circuit repeatedly adjusting the active resistance of the DC/DC converter. If the change of the output power of the solar cell array is positive, the active resistance of the DC/DC converter is adjusted in the same direction; but, conversely, if the change of the output power of the solar cell array is negative, the active resistance of the DC/DC converter is adjusted in an opposite direction.

Abstract: A method for detecting the charged state of a battery based on the measurements of open circuit voltage in which the charged state of a battery can be detected precisely regardless of the degradation state of the battery. Internal impedance of a battery is measured, voltage of the battery is measured under stable state, measurement of the battery voltage under stable state is subjected to raising correction depending on the measurement of internal impedance, and then charged state of the battery is determined based on the corrected value of battery voltage under stable state.

Abstract: A charging apparatus and a charging current detecting circuit thereof are disclosed in which it is possible to implement an electric circuit with little voltage loss by using an operational amplifier of low cost. A detecting resistor is disposed at the power voltage side of the downstream side of a power supply. The charging apparatus further includes an auxiliary power means for generating an auxiliary voltage to supplement the voltage limited to the range of an input voltage of the operational amplifier.

Abstract: A charger for a secondary battery including a positive electrode, a negative electrode including lithium-containing silicon represented by the composition formula LixSi, and an electrolyte. This charger includes: (1) a voltage detector that detects voltage of the secondary battery that is being charged; and (2) a charge controller that calculates the value x in LixSi included in the secondary battery from an output of the voltage detector and stops the charging of the secondary battery when the calculated value x reaches a predetermined threshold value. The charge controller has at least one settable threshold value including a first threshold value, and the first threshold value is 2.33 or less. The use of this charger makes it possible to charge the secondary battery such that it has a high capacity, or a higher capacity if necessary, without accelerating the deterioration of cycle life.

Abstract: A method for charging a lead acid storage battery to advantageously extend its life is described. The termination of a charging process is based upon an evaluation of the first derivative (dv/dt) and second derivative (d2v/dt2) of the applied charging voltage. By utilizing the first derivative (dv/dt) and second derivative (d2v/dt2) as charging criteria, an amount of overcharge is applied to the battery that takes into account the precise amount of amp-hours previously removed from the battery. A charger arrangement for performing a charging process of the invention also is described.

Abstract: A power supply apparatus according to the present invention includes a battery and a voltage detection circuit for detecting the voltage of the battery. The voltage detection circuit includes a differential amplifier which has a first input terminal for receiving a voltage based on the voltage of the battery and a second input terminal for receiving a predetermined triangular wave and outputs a rectangular wave with a pulse width modulated according to the voltage based on the voltage of the battery and a predetermined offset voltage, and an offset circuit which supplies the offset voltage to one of the first input terminal and the second input terminal so that the differential amplifier outputs a particular rectangular wave according to the offset voltage even when the voltage based on the voltage of the battery which is supplied to the first input terminal is 0.

Abstract: A circuit for conditioning a power supply whose graph of the power supplied as a function of the voltage at the terminals of the supply features a maximum comprises a DC/DC converter with an input to which power is supplied by the power supply and an output from which power is supplied to a load. A control circuit controls the converter in accordance with a power set point applied to the converter. The set point is a rising set point when the time derivative of the converter input voltage is higher than a negative first threshold value and a falling set point when the time derivative of the converter input voltage is lower than a positive second threshold voltage. The rate of variation of the average power when the set point is a rising set point is lower than the opposite of the rate of variation of the average power when the set point is a falling set point. The conditioning circuit enables the supply to deliver power at the maximum power point and is simple to implement.

Abstract: A first control unit 110 and second control unit 120 are disposed to a portable data terminal 100 having a heavy load group 140 and light load group 150. The first control unit 110 detects the output voltage of a secondary battery 105 and controls power supply to the heavy load group 140 by switching a first switch S1. When the first control unit 110 stops power supply to the heavy load group 140, it outputs a low level control signal CC to the second control unit 120. The load of driving the second control unit 120 is designed to be smaller than the load of driving the first control unit 110. When the control signal CC is received, the second control unit 120 starts detecting the output voltage of the secondary battery 105, and stops power supply to the switch light load group 150 and first control unit 110 if the output voltage is detected to drop to a preset threshold voltage.

Abstract: The present invention comprises a formation procedure for alkaline nickel-zinc cells, the procedure comprising the steps of assembling an alkaline nickel-zinc cell, charging the cell at a charging current rate until a first condition is achieved, wherein at the first condition the cell has a first cell voltage, maintaining the cell at the first cell voltage while applying a maintenance current to the cell until a second condition is achieved, and discharging the cell at a discharging current rate until a third condition is achieved, wherein the steps of charging, maintaining and discharging are repeated at least one time, and, thereafter the cell is finally charged at a final charging rate until the final condition is achieved.

Abstract: The present invention comprises a formation procedure for alkaline nickel-zinc cells, the procedure comprising the steps of assembling an alkaline nickel-zinc cell, charging the cell at a charging current rate until a first condition is achieved, wherein at the first condition the cell has a first cell voltage, maintaining the cell at the first cell voltage while applying a maintenance current to the cell until a second condition is achieved, and discharging the cell at a discharging current rate until a third condition is achieved, wherein the steps of charging, maintaining and discharging are repeated at least one time, and, thereafter the cell is finally charged at a final charging rate until the final condition is achieved.

Abstract: A charge control means (10) provided for a battery charging apparatus (1) conducts protection control for a battery pack (2) by transmitting a signal to an output control switch (14) for turning off an output when a rise rate of the temperature of the battery pack (2) detected based on information from a temperature detection terminal (8) is equal to or more than a predetermined value, or a rise rate of the voltage of the battery pack (2) detected based on information from a voltage detection terminal (9) is equal to or less than a predetermined value.

Abstract: A method and apparatus utilizing a new parameter for assessing battery charge acceptance for controlling the charging process of the battery. The charge acceptance parameter comprises a terminal voltage profile which is determined during a variation in a diagnostic current. The slope of the terminal voltage profile is used in the charging process to assess the charge acceptance ability of the battery and thereby control the charging current. For a first group of batteries including lead-acid and nickel-cadmium batteries, the terminal voltage profile is characterized by an increasing profile slope as the charge acceptance ability of the battery is reached. For a second group of batteries comprising nickel-metal hydride batteries, the terminal voltage profile is characterized by a profile slope which approaches zero as the charge acceptance ability of the battery is reached.

Abstract: A charging and discharging circuit for a pulse laser which enables the pulse laser to increase an oscillation frequency.

Abstract: To provide a battery charger capable of fully charging both an active battery and an inactive battery, which have different charging characteristics near the peak level, a voltage across the battery is periodically sampled during charging the battery. A voltage change is obtained by subtracting a voltage that has been sampled previously from the newly sampled voltage. Determination of the fully charged condition of the battery is made when a voltage change falls below a critical value (S1, S2) after identifying that the battery being charged is an active or inactive battery using another critical values (K1, K2 or K1′, K2′). The critical values S1 and S2 and another critical values K1 and K2 (or K1′ and K2′) are selectively referred to depending to the battery voltage change.

Abstract: A method and apparatus for creating, measuring and analyzing polarization voltages developed across an element, such as an electronic component or an electrochemical energy cell, or network of such elements, in response to a current mode excitation provided by a driver composed of a voltage controlled voltage source connected to one terminal of a Device Under Test and a voltage controlled current source connected to the other terminal of a Device Under Test. A voltage sensor, also connected across the Device Under Test, determines the magnitude and polarity of any potential appearing across the DUT; whenever the excitation current is exactly zero, this measured potential will be equal to the Open Circuit Potential of the DUT. This configuration of driver and sensor is known as a Kelvin connection.

Abstract: Provided is a charging method of a secondary battery capable of reducing the irreversible quantity in initial charge and discharge cycles after production of the battery and improving charge and discharge cycle characteristics. The secondary battery is at least comprised of an anode, a cathode, and an electrolyte and has a curve of anode potential or cathode potential against storage quantity, or an open-circuit voltage curve against storage quantity with inflection points. A charging operation of the secondary battery is carried out in a predetermined wave form at least until the inflection point. After passing the inflection point, until a fully charged state is achieved, the charging is performed in a different pattern from that before the inflection point.

Abstract: A “fuel gauge” for a pulse dischargeable alkali metal/solid cathode cell is described. The rate of voltage recovery is used to determine the state of charge of the cell. Voltage recovery includes recovery from one load to a second, lighter load, or a loaded condition to OCV. The present invention is particularly useful as an end-of-life indicator for a Li/CFx cell powering an implantable medical device.

Abstract: A method of charging a rechargeable battery which comprises charging the battery with a charging current; sampling conditions of the battery during charging to recognize potential adverse conditions within the battery; interrupting the charging current periodically to create current-free periods and sampling an open circuit voltage of the battery during each current-free period to identify potential overcharge conditions in the battery; lowering the charging current if any adverse conditions are identified and continuing charging with the charging current if adverse charging conditions are not identified; and terminating charging when a predetermined value is recognized. The method of charging nickel-metal hydride and nickel-cadmium batteries is based on switching charging current as soon as temperature related battery open circuit voltage reaches the first predetermined value, tapering current and continuing charging up to terminating point.

Abstract: A microprocessor couples to a voltage sensor through an analog to digital converter. The voltage sensor is adapted to be coupled across terminals of a battery. A small current source is also provided and adapted to be coupled across the terminal to the battery. The current source is momentarily applied to the battery and the resulting change in voltage is monitored using the microprocessor. The microprocessor calculates battery conductance based upon the magnitude of the differential current and the change in voltage and thereby determines the condition of the battery.

Abstract: A method for charging batteries using a solid state battery charger is disclosed which includes the steps of supplying a constant current to the batteries being charged until the battery voltage reaches a first threshold voltage value, supplying a constant voltage to the batteries being charged until current being drawn by the batteries reaches a threshold current value and supplying a constant current to the batteries being charged until a voltage rise per unit time threshold is met.

Abstract: A control circuit is provided to minimize the charging cycle time of a battery charging system by maximizing the length of time that high constant charging current is applied to a discharged battery. The control circuit includes a constant current (CC) error amplifier, a constant voltage (CV) error amplifier, an output amplifier, and two pole-splitting compensation networks. The control circuit works in conjunction with a power source to charge a secondary battery. The pole-splitting compensation networks allow the CC, CV, and output amplifiers to be configured for high gain, without sacrificing output stability. The control circuit provides a sharp transition between the CC mode and CV mode of operation. In the CC mode, fast bulk battery charging is provided. In the CV mode, the control circuit initially provides a "top-off" charge to the battery and subsequently safely maintains the battery at its fully charged state.

Abstract: A "fuel gauge" for a pulse dischargeable alkali metal/solid cathode cell is described. The rate of voltage recovery is used to determine the state of charge of the cell. Voltage recovery includes recovery from one load to a second, lighter load, or a loaded condition to OCV. The present invention is particularly useful as an end-of-life indicator for a Li/CF.sub.x cell powering an implantable medical device.

Abstract: A method of controlling the charging of a rechargeable battery and a charger for practicing the same are disclosed. The battery voltage of the rechargeable battery, a voltage across the internal resistance of the battery and a voltage across a current setting resistor are added together and applied to the voltage detection input of a controller in the form of a sum voltage. The controller detects the sum voltages in the ON state (during charging) and OFF state(during interruption of charging) of a control FET (Field Effect Transistor), and calculates a difference between them. The controller determines, based on the difference, whether or not the battery has been fully charged, and then controls charging on the basis of the result of the decision.

Abstract: An apparatus and method is provided for charging a rechargeable battery in a two-way pager. The pager has a transmitter, a main battery for supplying a main power source voltage, and the rechargeable battery for supplying a transmission power source voltage to the transmitter.

Abstract: A method of charging a rechargeable battery which comprises charging the battery with a charging current; sampling a charging voltage of the battery during charging to recognize potential adverse conditions within the battery; interrupting the charging current periodically to create current-free periods and sampling an open circuit voltage of the battery at a plurality of points during each current-free period to identify potential overcharge conditions in the battery; lowering the charging current if any of the above-identified adverse conditions are identified and continuing charging with the charging current if the potential adverse charging condition is not identified; and terminating charging when a negative slope on a chemical polarization versus time curve is identified below a pre-determined minimum level.

Abstract: The voltage of each of battery block of a battery is detected by a voltage sensor. Further, the temperature of the battery is detected by a temperature sensor. These detected values are supplied to a detecting section of a battery ECU. A judging section reads out the threshold value of the voltage stored in a memory, on the basis of the detected values of temperature, and compares the threshold value of the voltage with the detected voltage of each of the battery blocks. Then, if at least any one is less than the threshold value of the voltage, a relay is turned off. Furthermore, the threshold value of the voltage is arranged to be the voltage at the moment when the value of the current is suddenly increased by the discharge of a constant current of the battery.

Abstract: Instability and oscillation are avoided in an overcharge/overdischarge control circuit by providing comparators with sufficient gain to minimize leakage current penetration into control circuitry when an output of a comparator used for comparing the output voltage of a secondary cell with a reference voltage is at an intermediate level. An overcharging/overdischarging detection circuit with two secondary cells connected in series has voltage dividing resistors connected in parallel therewith for producing a divided output voltage for each secondary cell, the divided output voltages each being supplied to a respective comparator. A first comparator has an input stage comprising N-channel MOS devices. A second comparator has an input stage comprising P-channel MOS devices.

Abstract: A microprocessor couples to a voltage sensor through an analog to digital converter. The voltage sensor is adapted to be coupled across terminals of a battery. A small current source is also provided and adapted to be coupled across the terminal to the battery. The current source is momentarily applied to the battery and the resulting change in voltage is monitored using the microprocessor. The microprocessor calculates battery conductance based upon the magnitude of the differential current and the change in voltage and thereby determines the condition of the battery.

Abstract: By monitoring both charge current and the battery voltage (306, 308) the likelihood of overcharging a battery is reduced. Battery voltage is compared to a predetermined limit (310) and the battery goes into trickle charge if the predetermined limit is exceeded (312), but now by also determining if a positive delta in charge current has occurred (314), the charger can trickle charge the battery (312) even if the cutoff voltage is never exceeded.

Abstract: There is provided herein a joystick interface which includes circuitry to detect when the joystick output signal has been at a steady-state level for a predetermined period of time and upon detection of that condition, the circuitry powers down at least some of the circuitry associated with providing the digital signal representation to the computer. In one particular embodiment of the invention, analog circuitry including a slope detector, makes use of two non-overlapping clocks to sample data and provide it to a comparator. The comparator is used to determine if there has been any change between consecutive or sequential samples, representative of joystick shaft movement. After a predetermined number of comparisons showing no change in either a neutral joystick position or a non-neutral joystick position, the digital circuitry is powered-down to a reduced power operating mode.

Abstract: A control circuit controls a battery charger so as to prevent damage to NiCAD or NiMH batteries resulting from overheating due to overcharging. During charging, the battery voltage is monitored through a filter, buffer, amplifier and sample and hold circuit. The sampled voltage is time differentiated to determine its rate of change, and a control signal is generated for switching the battery charger from a rapid charge mode to a trickle charge mode when the negative rate of change of the battery voltage exceeds a pretermined reference voltage, thereby identifying that the battery voltage has started to decay from its peak voltage.

Abstract: A method and apparatus for processing rechargeable batteries include using a processor arranged to monitor the voltage of a battery when it is being discharged and to terminate the discharge after detecting that the rate of change of the voltage has passed through a termination pattern indicative of exhaustion of a cell of the battery. The determination is made by monitoring the voltage during discharge and detecting when the voltage curve thereof exhibits first convexity followed by concavity. The degree of convexity and concavity, and the time interval within which they must occur, are determined by the processor. The discharge is also terminated if the voltage reaches a predetermined voltage or if, after the termination pattern is detected, and before the voltage has reached a predetermined voltage, a predetermined amount of charge is removed from the battery.

Abstract: Methods and circuits are disclosed which terminate charging of a battery when the maximum charge is reached. Maximum charge is reached when the battery voltage has peaked, after a long rise, and just starts to drop. This small voltage drop, or delta, is detected by a charger control which compares the real time battery voltage with a previously sampled battery voltage. Upon detecting this small voltage drop, the charger control terminates the charging process. Implementations using an analog delta voltage detection and a digital delta voltage detection are described.