Abstract: A system for testing an electronic device comprises a first output, a second output, and a third output connected to a positive input, an identification input, and a negative input of the electronic device, respectively. The system further comprises a switch comprising at least two dynamic contacts, each of which is connected to a resistor for the use of identification.

Abstract: An electronic vehicle tester includes a battery tester configured to measure a parameter of a battery of a vehicle. A tire tester is configured to receive a parameter of a tire of the vehicle. A wireless receiver can be configured to receive pressure information from a transmitter associated with a tire of a vehicle.

Abstract: A method for estimating an operating life for an electrical energy storage system electrically connected to transmit power to a hybrid powertrain system includes monitoring temperature state-of-charge and electric current of the electrical energy storage system, calculating a battery life metric for a time interval based upon the temperature, the state-of-charge, and the electric current discharge, determining a total battery life metric therefrom and determining the remaining operating life of the electrical energy storage system.

Abstract: A system includes an implantable battery, an implantable medical device powered by the battery, a first resistance, a second resistance, a first memory register and a second memory register. The implantable medical device has first and second current drain states. The first resistance is connected to the battery through a first current path when the device is in the first current drain state, wherein current is prevented from flowing through the first current path when the device is in the second current drain state. The second resistance is connected to the battery through a second current path when the device is in the second current drain state, wherein current is prevented from flowing through the second current path when the device is in the first current drain state. The first memory register is configured to store a cumulative first current drain state count indicative of total charge drawn from the battery when the device is in the first current drain state.

Abstract: The rechargeable battery abnormality detection apparatus is provided with an internal short circuit detection section (20b) that monitors rechargeable battery (1) voltage change when no charging or discharging takes place, and detects internal short circuit abnormality when battery voltage drop during a predetermined time period exceeds a preset threshold voltage; a degradation appraisal section (20d) that judges the degree of rechargeable battery degradation; and a threshold control section (20c) that incrementally increases the threshold voltage according to the degree of degradation determined by the degradation appraisal section (20d).

Abstract: A rechargeable battery state-of-charge quantifying apparatus for use in a vehicle equipped with an electric motor and a rechargeable battery which supplies electric power to the motor to produce a driving torque. The apparatus quantifies a state-of-charge of the rechargeable battery and defines a minimum value of a state-of-charge of the rechargeable battery at which the rechargeable battery is permitted to produce a degree of electric power required to run the vehicle as a lower limit. The lower limit is increased as the rechargeable battery ages, thereby ensuring the stability in supplying the amount of electric power to the motor which is required to run the vehicle regardless of aging of the battery.

Abstract: A circuit that indicates an impedance of a battery dielectric includes a signal generator module that flows a first current from a ground to a first terminal of a battery. A sensor circuit generates a signal based on a second current that flows from a second terminal of the battery through a resistance to ground. The second current includes the first current and a third current that flows to ground via an impedance presented by a battery dielectric housing. A signal conversion module generates an output signal based on the signal. The output signal represents the impedance presented by the battery dielectric housing.

Abstract: An early warning method for an abnormal state of a lithium battery and a recording medium applicable to a portable electronic device are provided. The method includes the following steps. A plurality of curves of voltage against electric quantity is obtained according to different predicted average current consumptions of the portable electronic device. An operating average current consumption and an operating electric quantity from a first voltage to a second voltage are obtained when the lithium battery at an operating test state in a unit time. One of the curves of voltage against electric quantity is searched, and a warning electric quantity is obtained in a range from the first voltage to the second voltage. The warning electric quantity is compared with the electric quantity, so as to provide an early warning of an abnormal state.

Abstract: Methods and systems for determining a state of charge of a battery are provided. A first component of the state of charge is calculated based on a first property of the battery. A second component of the state of charge is calculated based on a second property of the battery. The first component of the state of charge is weighted based on a rate of change of the first property relative to a change of the state of charge. The second component of the state of charge is weighted based on a rate of change of the second property relative to a change of the state of charge. The state of charge is determined based on the first and second weighted components.

Abstract: The present invention relates to a voltage detecting circuit for detecting a voltage range of a power source. The voltage detecting circuit includes a micro controlling unit, a boost circuit and a plurality of divider resistors. The micro controlling unit includes a general input/output port and a controlling input/output port. The boost circuit provides a constant voltage. A judgment voltage is obtained according to the divider resistors, the constant voltage and a voltage of the power source. A digital level signal is issued by the general input/output port according to the judgment voltage. In response to the digital level signal, the micro controlling unit generates a corresponding prompt associated with the voltage status of the power source.

Abstract: A disclosed circuit for detecting remaining battery capacity includes: a current detection unit detecting a charge and discharge current of a battery; a remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals when the charge and discharge current detected in the current detection unit is not more than a predetermined value and at second time intervals shorter than the first time intervals when the charge and discharge current exceeds the predetermined value; and an interrupt signal generation unit generating an interrupt signal when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery.

Abstract: A method and apparatus that allows for controlling operating time of a portable computer system and a peripheral device. A portable computing system that includes a rechargeable power supply and that includes a connection mechanism for coupling to a peripheral device is used to control operating time of the portable computer system and the peripheral device. In one embodiment, a user can choose between maximizing the operating time of the portable computer, maximizing the operating time of the peripheral device, or maximizing the life of the entire system (maximizing the operating time of the portable computer system and the peripheral device). When operating time of the portable computer system is to be maximized, power is sent from the peripheral device to the portable computer system to extend the operating time of the portable computer system.

Abstract: The invention provides a system and battery including a state-of-charge indicator (SOCI) to monitor and display the amount of charge within the battery. The SOCI is capable of operating in a hibernate mode, an active mode, and/or a sleep mode. The battery may be manufactured, shipped and/or stored with the SOCI operating in a power-saving hibernate mode. The SOCI may exit the hibernate mode and begin operating in active mode if a physical key connected to the battery is removed. In addition, the SOCI may operate in a sleep mode while the battery is not being used to conserve power. Furthermore, the invention provides a method of making a battery including a SOCI to monitor and display the state of charge of the battery.

Abstract: A method and a circuit for detecting the state of supply of a load by a variable voltage, including measuring the difference between values representative of the variable supply voltage and of a voltage across the load.

Abstract: A battery management system is provided. A voltage of a first battery cell is charged to a capacitor. Then, the voltage of the capacitor is measured, the measured voltage being the voltage of the first battery cell. Subsequently, a voltage of a second battery cell is again charged to the capacitor while the capacitor holds the voltage of the first battery cell. The voltage of the capacitor is then measured, the measured voltage being the voltage of the second battery cell. With such a scheme, the time for discharging the capacitor may be removed, and accordingly, a period for measuring a voltage of the battery cell may become shorter.

Abstract: To provide a voltage measurement device for measuring a battery voltage of a secondary battery formed by serially connecting a plurality of battery blocks, which is able to calculate the battery voltage in block units even though a potential detection line is disconnected. Specifically, when the voltage detection unit fails to measure the battery voltage of the measurement target battery block by selecting potential detection lines connected to both terminals of the measurement target battery block, the switch control unit selects the potential detection lines connected to both terminals of the battery block group including a serially connected plurality of battery blocks including the measurement target battery block, then measures the integrated voltage of the battery block group, and measures the battery voltage of the measurement target battery block based on the measured integrated voltage.

Abstract: A state of charge (SOC) compensation method of a battery and a battery management system using the same. A charge/discharge current of the battery is used for calculating the SOC and an SOC voltage that is a value in an OCV table, a rheobasic voltage is calculated, an error in the SOC is measured by using a difference between the SOC voltage and the rheobasic voltage, and a range of the error is determined among multiple effective ranges. Subsequently, the SOC is compensated by using a compensation SOC set in correspondence with a range in which the error is included to thereby measure a more accurate SOC of the battery.

Abstract: This disclosure describes methods and apparatus for indicating battery cell status on a battery pack assembly used during mechanical ventilation. Embodiments described herein seek to provide methods for indicating battery cell status on the exposed exterior of a battery assembly pack both when the battery is in use and when the battery is not in use during mechanical ventilation. Embodiments utilize power from the ventilator as well as power from the battery pack itself to light the indicators during periods of battery use and non-use, respectively. Embodiments described herein further seek to provide an apparatus indicating battery cell status on the exposed exterior of the battery pack assembly during mechanical ventilation. Embodiments described herein further seek to provide an apparatus for a battery pack assembly used during mechanical ventilation. Embodiments described herein seek to provide a system for a ventilation system with an inserted battery pack assembly.

Abstract: The battery management system (BMS) measures a state of charge (SOC) of a battery by using a total amount of charge corresponding to a total amount of discharge accumulation. The BMS, outputting a SOC of a battery to an engine control unit (ECU), includes a sensor, state of health (SOH) and SOC measurers, a total amount of charge (TAC) determiner, and an output unit. The sensor detects a pack current and a pack voltage of the battery. The SOH measurer outputs a SOH of the battery by using the pack current and voltage. The SOC measurer measures a SOC of the battery by using the pack current and a TAC of the battery. The TAC determiner accumulates a total amount of discharge accumulation by using the pack current, determines a TAC corresponding to the total amount of discharge accumulation, and delivers the determined TAC to the SOC measurer. The output unit outputs the SOC and SOH to the ECU.

Abstract: According to one exemplary embodiment, a power gauge for accurately measuring current consumed by a load coupled to a power source includes a current sense resistor having a first terminal coupled to the power source and a second terminal coupled to the load. The power gauge further includes a first integrator configured to integrate a voltage at the first terminal of the current sense resistor during a time period and to output a first integrated voltage. The power gauge further includes a second integrator configured to integrate a voltage at the second terminal of the current sense resistor during the time period and to output a second integrated voltage. A difference between the first and second integrated voltages can be used to accurately determine the current consumed by the load during the time period.

Abstract: The invention provides a system and battery including a state-of-charge indicator (SOCI) to monitor and display the amount of charge within the battery. The SOCI is capable of operating in a hibernate mode, an active mode, and/or a sleep mode. The battery may be manufactured, shipped and/or stored with the SOCI operating in a power-saving hibernate mode. The SOCI may exit the hibernate mode and begin operating in active mode if a physical key connected to the battery is removed. In addition, the SOCI may operate in a sleep mode while the battery is not being used to conserve power. Furthermore, the invention provides a method of making a battery including a SOCI to monitor and display the state of charge of the battery.

Abstract: The present invention relates to a battery protection circuit for protecting a plurality of batteries connected in series. The battery protection circuit includes: a controller for monitoring the batteries and outputting control signals based on predetermined conditions associated with the batteries; a first N-channel MOSFET and a second N-channel MOSFET coupled in a common-drain configuration in a low-side path, wherein at least one of the first and second N-channel MOSFETs turns off in response to the control signal received from the controller when at least one of the predetermined conditions is detected; and a gate protection circuit for preventing gate-to-source voltages of the first and second N-channel MOSFETs from exceeding a predetermined gate-to-source voltage level.

Abstract: The invention discloses a method for precisely estimating the remaining capacity of a rechargeable battery in a practical system. To evaluate the remaining capacity of a battery through a calibrated current which is calculated from a predictable capacity close to the end of discharge or to the end of full charge, so that the remaining capacity of battery will approach end points smoothly. A system can thus detect battery status and take necessary actions safely. Battery aging problem is considered while calculating the remaining capacity and the full charge capacity (FCC) of battery is also updated according to the total cumulated charges during a charge or discharge stage.

Abstract: A method of controlling a fuel cell system includes applying alternating current (AC) signals to an individual fuel cell. The AC signals have a plurality of different frequencies. A voltage across the individual fuel cell is determined at each of the plurality of different frequencies. An impedance characteristic of the individual fuel cell is determined based at least in part on the voltage across the individual fuel cell at each of the plurality of different frequencies. The individual fuel cell is controlled based at least in part on the impedance characteristic.

Abstract: An arrangement for monitoring the current or state of charge (SOC) of an energy system (230) having one or more series-connected strings (S1, S2, . . . Sn) of battery cells (C1, C2, . . . Cn). The battery cells each have respective dissipative devices (D1, D2, . . . Dn) selectively connectable in parallel therewith for balancing cell voltages in the string. The dissipative devices are of predetermined, typically equal, impedance value. The voltage across each cell (Vc1, Vc2, . . . Vcn) may be separately monitored, such that by dividing the monitored voltage across a cell by the impedance value of a dissipative device connected in parallel therewith, the dissipative current is determined. A summation of all of the dissipative currents yields an error value, which error value is then removed from the measured gross current (Ibat) flowing through the combined battery cells and dissipative devices to yield a corrected value of current (Ibatnet). A corrected SOC value (Qnet) is obtainable in a similar manner.

Abstract: The present invention relates to a state of charge (SOC) compensation method for a vehicle using electrical energy, and a battery management system using the SOC compensation method. To determine the SOC of the battery, charge and discharge current of the battery is used to calculate a first SOC of the battery and a first corresponding voltage, a rheobasic voltage is calculated, an integration error corresponding to a difference between the first voltage and the rheobasic voltage is calculated, a SOC compensation factor is added to the first SOC when the integration error is greater than a first threshold value, and a SOC compensation factor is subtracted from the first SOC when the integration error is less than a second threshold value.

Abstract: A system for and method of estimating the state-of-age of a secondary cell utilizing an adaptive group filter algorithm, includes battery current, voltage, and temperature sensors, a communication device, and a controller communicatively coupled to the sensors and device, configured to filter data by analyzing only sample data points from instantaneous charge or discharge events, selecting only a sample of n instantaneous points for further regression, including n/2 charge event points and n/2 discharge event points, and separately averaging the charge and discharge event points, and further configured to determine the state-of-age by determining a resistance slope based on the rate of current and voltage change between the averages of the points, and matching the slope to a calibrated scalar or relational database.

Abstract: Disclosed are an apparatus and a method for accurately estimating a state of charge of a battery, which can measure a change of temperature and an open circuit voltage so as to estimate the state of charge at an initial time when a vehicle is not driven, and while measuring a decrement in a capacity of a battery according to charging and discharging of the battery when the vehicle is driven. The method includes the steps of: measuring a temperature in an initial estimation of the state of charge; measuring an open circuit voltage; obtaining parameters indicating a change of the open circuit voltage according to a change of temperature; and calculating the state of charge using the parameters and the open circuit voltage which is measured depending on the obtained parameters.

Abstract: Provided is an apparatus for detecting state of charge (SOC) of a battery. A voltage of a battery pack (100) is detected by voltage sensors (120-1) to (120-n). A determining unit (160) samples currents at times when the battery voltage reaches predetermined threshold voltages (Vth1, Vth2) respectively, and calculates an open end voltage (Vocv), based on representative values (I1, I2) of the sampled currents and threshold voltages (Vth1, Vth2). Furthermore, based on a correspondence relationship between the voltage (Vocv) and the state of charge (SOC) which is determined in advance, the state of charge (SOC) that corresponds to the calculated voltage (Vocv) is calculated.

Abstract: A method and apparatus that allows for controlling operating time of a portable computer system and a peripheral device. A portable computing system that includes a rechargeable power supply and that includes a connection mechanism for coupling to a peripheral device is used to control operating time of the portable computer system and the peripheral device. In one embodiment, a user can choose between maximizing the operating time of the portable computer, maximizing the operating time of the peripheral device, or maximizing the life of the entire system (maximizing the operating time of the portable computer system and the peripheral device). When operating time of the portable computer system is to be maximized, power is sent from the peripheral device to the portable computer system to extend the operating time of the portable computer system.

Abstract: A method and a device are provided for limiting the driving speed of a motor vehicle that allow a selectable, fixed fuel consumption per distance traveled to be maintained without limiting short-term acceleration. In this context, the driving speed is limited to a maximum value (vmaxbe), at which a predefined maximum fuel consumption (Besetpoint) for steady driving speed is not exceeded.

Abstract: The invention provides a system and battery including a state-of-charge indicator (SOCI) to monitor and display the amount of charge within the battery. The SOCI is capable of operating in a hibernate mode, an active mode, and/or a sleep mode. The battery may be manufactured, shipped and/or stored with the SOCI operating in a power-saving hibernate mode. The SOCI may exit the hibernate mode and begin operating in active mode if a physical key connected to the battery is removed. In addition, the SOCI may operate in a sleep mode while the battery is not being used to conserve power. Furthermore, the invention provides a method of making a battery including a SOCI to monitor and display the state of charge of the battery.

Abstract: At least one of continuous disconnection, intermittent disconnection, and temporary disconnection, of wireless communication between the input device and the game apparatus is detected. Remaining battery amount data representing a remaining battery amount of the input device is obtained via the wireless communication. It is determined that the power of the input device is insufficient based on that the wireless communication is detected to be disconnected and that the obtained remaining battery amount data represents a remaining battery amount of a predetermined level or lower. When it is determined that the power is insufficient, the power insufficiency is notified.

Abstract: This invention provides an electronic device that has a battery with a power storage unit and a display module, a power detector and a display control module. The power storage unit is for storing electrical power and the display module is placed on the surface of the battery. The power detector is selectively coupled to the battery, and generates a remaining power signal after detecting the remaining power in the battery. The remaining power signal is used to control the display control module. When the power detector is selectively coupled to the battery, the display module shows the current remaining power in response to the action of the display control module. When the power detector is separated from the battery, the display module is essentially capable of maintaining the showing of remaining power.

Abstract: A battery control module for a battery system comprises a voltage measuring module that measures battery and a current measuring module that measures battery current. A state of charge (SOC) module communicates with the current and voltage measuring modules and estimates SOC at least one of when an accumulated charge swing during charge is greater than or equal to an accumulated discharge swing during a prior discharge and a negative of a charge current is within a predetermined window of a negative of a retained discharge current during the prior discharge and/or when an accumulated discharge swing during discharge is greater than or equal to an accumulated charge swing during a prior charge and a negative of a discharge current is within a predetermined window of a negative of a retained charge current during the prior charge.

Abstract: A method and apparatus that allows for controlling operating time of a portable computer system and a peripheral device. A portable computing system that includes a rechargeable power supply and that includes a connection mechanism for coupling to a peripheral device is used to control operating time of the portable computer system and the peripheral device. In one embodiment, a user can choose between maximizing the operating time of the portable computer, maximizing the operating time of the peripheral device, or maximizing the life of the entire system (maximizing the operating time of the portable computer system and the peripheral device). When operating time of the portable computer system is to be maximized, power is sent from the peripheral device to the portable computer system to extend the operating time of the portable computer system.

Abstract: A capacitor charging semiconductor apparatus including a plurality of serially connected capacitors to be charged. A direct current source is applied to the plurality of capacitors. A plurality of bypass transistors is provided to bypass charge current supplied to the plurality of capacitors when a voltage of a capacitor exceeds a prescribed reference level. A plurality of parallel monitor circuits is provided to control the plurality of bypass transistors to equally charge the plurality of capacitors. A plurality of capacitor connection terminals is connected to both ends and intersections of the plurality of capacitors. A plurality of transistor connection terminals is connected to the plurality of control terminals of the bypass transistor. A prescribed number of capacitors is optionally charged by increasingly shorting a number of capacitor connection terminals from the highest and lower voltage side capacitor connection terminals.

Abstract: A circuit for monitoring charge/discharge of a battery is disclosed. The circuit may comprise first and second terminal capacitors disposed for first and second terminals of a current detection resistor connected to a battery. The first and second terminal capacitors may develop an integrated voltage responsive to the charge/discharge current obtained from the individual terminals. The circuit may also include at least one comparator for comparing the individual integrated voltages developed by the first and second terminal capacitors with a reference voltage, the comparator having respective outputs which change when the individual integrated voltages reach the reference voltage. A terminal-by-terminal output change count difference output unit may count the number of times the output of the comparator changes and may output the difference between the number of times of change corresponding to the first terminal and the number of times of change corresponding to the second terminal.

Abstract: A method and a device for determining the state of a vehicle battery in which the battery voltage is measured and information regarding the state of the vehicle battery is derived from the measured battery voltage by means of an integration procedure. A variable weighting factor is taken into account in the integration procedure.

Abstract: The invention provides a system and battery including a state-of-charge indicator (SOCI) to monitor and display the amount of charge within the battery. The SOCI is capable of operating in a hibernate mode, an active mode, and/or a sleep mode. The battery may be manufactured, shipped and/or stored with the SOCI operating in a power-saving hibernate mode. The SOCI may exit the hibernate mode and begin operating in active mode if a physical key connected to the battery is removed. In addition, the SOCI may operate in a sleep mode while the battery is not being used to conserve power. Furthermore, the invention provides a method of making a battery including a SOCI to monitor and display the state of charge of the battery.

Abstract: A sensor 10 comprises an array of electrostatic sensor elements 12, each centred at a respective sensing position 14. Each element produces a respective output signal at 16. The outputs 16 can be used to drive respective pixels of a display. This allows an image to be created to represent the electrostatic charge distribution across the region to which the sensor is directed.

Abstract: A communication portion of a video camera receives expected power information of a printer from the printer, and also receives battery power information from a battery pack. When a microcomputer judges that there is any shift to a state where the power consumption amount under operating state is varied, that is, the printer is under a print standby state for printing operation, an operating portion reads out expected power information of the video camera under operation of the printer which is stored in advance is read out from the storage portion to calculate the expected power consumption amount of a video camera system under the operation of the printer on the basis of the expected power information of the printer received by the communication portion and the expected power information of the video camera read out, and the battery residual amount time is determined on the basis of the expected power consumption amount.

Abstract: The remaining capacity of a battery obtained by integrating current and that obtained from the estimated open circuit voltage of the battery are weighted with a weight which varies depending on the operating conditions of the battery as needed and the weighted remaining capacities are combined into the final remaining capacity. Thus, the disadvantages of the remaining capacity based on current integration and those of the remaining capacity based on the estimated open circuit voltage cancel each other out and the advantages of the respective remaining capacities can be fully utilized. The uniform calculation accuracy can be ensured and the final remaining capacity can always be obtained with accuracy.

Abstract: A device (8) for determining the energy state of an energy storing device (7) of a data carrier (4) in which a voltage stabilizer (9) is used to derive a stabilized DC voltage for the supply of the data carrier from an unstabilized DC voltage available at the energy storing device. The device (8) has an evaluation circuit that includes an auxiliary capacitor (13), a measurement circuit (15, 16, 21) for measuring the charging times of the auxiliary capacitor, and an evaluation logic (18). A quantity describing the energy state of the energy storing device is provided at the output of the evaluation circuit.

Abstract: An information handling system that includes a processor, a memory, a program, a battery, and a module. The module receives a request for first information associated with the battery from the program, accesses the first information, converts the first information into second information, and provides the second information to the program in response to the request.

Abstract: This invention relates to a limited range low voltage testing, regulating, and indicating device comprising a detector and low voltage measurer of magnitude in a switch-regulated power supply circuit wherein indicator LEDs are operated directly from a power supply wherein continually increasing current draw provided by shunt switching operates to cause the first display LEDs to “fade” in an overlapping pattern of activation, in and out with slight voltage changes. Increased voltage causes a second LED to turn on. Further increased voltage causes the second LED to turn off and a third LED to turn on. Shunt and series connected voltage regulators selectively exert control over the LEDs.

Abstract: A method to compute an amount of energy taken from a battery coupled to a switching power converter is disclosed. The switching power converter charges a capacitor to a voltage and by the application of one or more control pulses to the switching power converter the voltage on the capacitor is maintained within a predetermined range having an upper voltage. The voltage on the capacitor is sampled and one or more control pulses are applied to the switching power converter to raise the voltage on the capacitor to the upper voltage. The amount of energy taken from the battery is computed based on measurement of a change in voltage on the capacitor over an elapsed time.

Abstract: A method and apparatus that allows for controlling operating time of a portable computer system and a peripheral device. A portable computing system that includes a rechargeable power supply and that includes a connection mechanism for coupling to a peripheral device is used to control operating time of the portable computer system and the peripheral device. In one embodiment, a user can choose between maximizing the operating time of the portable computer, maximizing the operating time of the peripheral device, or maximizing the life of the entire system (maximizing the operating time of the portable computer system and the peripheral device). When operating time of the portable computer system is to be maximized, power is sent from the peripheral device to the portable computer system to extend the operating time of the portable computer system.

Abstract: A processor (13) operates to determine amount of charge presently stored in a battery by determining that the battery is in a zero-current relaxed condition. Circuitry (16,23) including a first ADC (16) measures an open circuit voltage (OCV) of the battery prior to a period of time during which flow of current through the battery is not negligible. A program executed by the processor correlates the measured open circuit voltage (OCV0) with a corresponding value of the variable and selects the corresponding value as a value of the variable.

Abstract: A portable instrument capable of evaluating the electro-chemical deterioration of an object under test such as a multi-cell valve regulated battery (10) and comprising means capable of temporarily applying across a battery cell a controlled frequency electrical signal derived from an internal battery (11) within the instrument, the signal being an oscillatory current or voltage controlled injected signal, further means for detecting returned data resultant from the signal application, and utilizing the data and a tailored mathematical algorithm in dedicated computer software to derive the data required. Such an instrument may be used to test battery systems of the type required for uninterruptible back-up power supplies in large industrial installations.