Abstract: An apparatus for diagnosing a battery may include a voltage measurement unit that measures a voltage of a battery cell, a fitting equation calculation unit that calculates a fitting equation for the voltage of the battery cell, and a diagnostic unit that diagnoses whether or not the battery cell is abnormal based on the fitting equation for the voltage of the battery cell.

Abstract: A method of evaluating an all-solid-state battery includes preparing the all-solid-state battery. A charge level of the all-solid-state battery is adjusted to produce a first potential difference between a positive electrode and a negative electrode. The positive electrode or the negative electrode is selected as a reference electrode. After the charge level is adjusted, an operation to insert a conductive rod-shaped member into a stack portion along a direction of stack of the positive electrode and the negative electrode is performed while a second potential difference between the reference electrode and the rod-shaped member is measured. The rod-shaped member is stopped. The all-solid-state battery is evaluated based on a state of the all-solid-state battery after the rod-shaped member is stopped.

Abstract: A battery diagnosis device includes a voltage measurement unit for measuring a voltage of a battery cell, a fitting value calculation unit for calculating a fitting voltage of the battery cell in a rest section after charging and discharging of the battery cell, and a diagnosis unit for diagnosing an abnormality of the battery cell by comparing the measured voltage measured by the voltage measurement unit and the fitting voltage calculated by the fitting value calculation unit, with respect to the rest section of the battery cell.

Abstract: In representation processing, when a capacity retention is higher than a threshold value while a warranty condition is satisfied, an ECU has the capacity retention shown in a first manner. When the capacity retention is equal to or lower than the threshold value while the warranty condition is satisfied, the ECU has the capacity retention shown in a second manner.

Abstract: Determining an energy storage device plan includes determining a benefit gradient associated with charging or discharging of an energy storage. It further includes determining, using an energy storage lifetime model, a cost gradient associated with a degradation of the energy storage due to charging or discharging. It further includes applying a threshold to the benefit gradient and the cost gradient. It further includes facilitating charging or discharging of the energy storage based at least in part on the threshold being met or exceeded.

Abstract: A method and apparatus of an emergency starting power supply used to start a device or energize a battery. This emergency starting power supply automatically detects the contact impedance of the device or battery and provides prompts from a user interface to the user based on this detected contact impedance. The prompts guide the user as the user on how to adjust the impedance of the connections to the device or battery so that it is connected optimally to the device or battery so that the emergency starting power supply can provide the device or battery with enough energy to start the motor or engine.

Abstract: Systems and methods for monitoring and management of an electronic device are discussed here. An authentication request is received from a user for access to an electronically secured compartment of an electronic device. Authentication data is obtained from the user. An authentication request that includes a device identifier for the electronically secured compartment and the authentication data is transmitted to a cloud-based authentication service. Access to the electronically secured compartment is provided upon receipt of an indication of an association between the user and the electronically secured compartment from the cloud-based service provider.

Abstract: An apparatus includes a first analog-to-digital converter configured to measure a first reference voltage and a third reference voltage. The apparatus also includes a second analog-to-digital converter configured to measure a second reference voltage and a fourth reference voltage. The apparatus also includes a controller configured to calculate a first resistance ratio, and determine a positive high voltage associated with the positive high voltage direct current input signal based, at least in part, on the first resistance ratio. The controller is further configured to calculate a second resistance ratio, and determine a negative high voltage associated with the negative high voltage direct current input signal based, at least in part, on the second resistance ratio.

Abstract: Systems and methods for monitoring and management of an electronic device are discussed here. An authentication request is received from a user for access to an electronically secured compartment of an electronic device. Authentication data is obtained from the user. An authentication request that includes a device identifier for the electronically secured compartment and the authentication data is transmitted to a cloud-based authentication service. Access to the electronically secured compartment is provided upon receipt of an indication of an association between the user and the electronically secured compartment from the cloud-based service provider.

Abstract: An automated vehicle inspection system includes a diagnostic terminal mounted in a vehicle and connected to an engine control unit (ECU) of the vehicle, sequentially operating individual electric components through the ECU based on stored electric component inspection items while the vehicle passes through a watertight booth and receiving individual operating currents measured to determine whether the electric components normally operate, a transceiver connecting to the diagnostic terminal and a wireless diagnostic communication network through an antenna disposed in the watertight booth process line, and an inspector recognizing a vehicle ID of a vehicle that enters the watertight booth, transmitting inspection items according to a vehicle type and specification of the vehicle ID to the diagnostic terminal through the diagnostic communication network, and recognizing a vehicle ID of a vehicle that leaves the watertight booth to collect inspection results determined in the diagnostic terminal.

Abstract: In representation processing, when a capacity retention is higher than a threshold value while a warranty condition is satisfied, an ECU has the capacity retention shown in a first manner. When the capacity retention is equal to or lower than the threshold value while the warranty condition is satisfied, the ECU has the capacity retention shown in a second manner.

Abstract: A redox flow battery system includes a redox flow battery that has a redox flow cell and a supply/storage system. The supply/storage system has first and second electrolytes for circulation through the redox flow cell. At least the first electrolyte is a liquid electrolyte that has electrochemically active species with multiple, reversible oxidation states. A secondary cell is operable to monitor concentration of one or more of the electrochemically active species. The secondary cell has a counter electrode, a flow passage that connects the counter electrode with the redox flow battery to receive the first or second electrolyte, a working electrode, and a separator. The working electrode is isolated from receiving the electrochemically active species of the first and second electrolytes except for a transport passage connecting the flow passage and the working electrode. The transport passage limits movement of the electrochemically active species to the working electrode.

Abstract: In one aspect, an embodiment of this invention comprises an apparatus for updating an active fuel gauge of a battery cell. The apparatus comprises a memory, a sensor, and a processor. The memory stores data regarding an active fuel gauge of the battery cell based on a first voltage and state of charge (SOC) relationship. The processor receives first, second, and third resting voltage measurements at different times. The processor calculates differences in capacity between pairs of the resting voltage measurements based on the first voltage and state of charge (SOC) relationship. When the differences are equal the reference capacity difference, the processor identifies an estimate of a remaining capacity of the battery cell corresponding with the active fuel gauge. When the differences are not equal to the reference capacity difference, the processor updates the active fuel gauge based on an identified second voltage and SOC relationship.

Abstract: A system and a method are for estimating an operating parameter value of an energy storage device arranged to provide power for propulsion for an electric or hybrid vehicle. In an embodiment, the method includes determining a first operating parameter value of the energy storage device at a first time; establishing a reference operating parameter value from pre-determined experimental data relating the operating parameter to a time related parameter; and based on the reference operating parameter value and the first operating parameter value, recursively calculating a second operating parameter value of the energy storage device at a second time subsequent to the first time. The recursive calculation includes a tuning parameter for modifying a portion of the reference operating parameter value to be included in the second operating parameter value.

Abstract: Disclosed is a battery state estimation method and apparatus, the method includes extracting data from target intervals in sensing data of a battery, generating feature vectors of the data extracted from each of the target intervals, applying a weight to each of the generated feature vectors, merging the feature vectors to which the weight is applied, and determining state information of the battery based on the merging.

Abstract: This battery capacity estimation device is provided with: a condition variable acquisition unit which acquires standard variable values (Tstd, Istd, V1std, V2std) indicating a standard charging condition in a secondary battery and measurement variable values (Tmes, Imes, V1mes, V2mes) indicating an actual charging condition obtained by measurement; and a capacity estimation unit which estimates the maximum capacity from a relationship between the standard variable values and the measurement variables acquired by the condition variable acquisition unit, wherein the capacity estimation unit calculates an apparent capacity (?Qmes/?SOC) by using a uniform calculation method regardless of a change in charging condition, and estimates the maximum capacity (Qmax) by adding, to the apparent capacity, a correction amount obtained by using the differences between the measurement variables and the standard variables.

Abstract: An in-situ coin cell support device for transmission mode X-ray diffraction analysis capable of controlling temperature. The device includes a coin cell seating unit including a seating part for receiving an in-situ coin cell, a positive electrode tab coupled to the seating part and connected to a positive electrode of the in-situ coin cell, and a negative electrode tab coupled to the seating part and connected to a negative electrode of the in-situ coin cell, a housing having a heat-insulating function, which surrounds the coin cell seating unit such that the positive and negative electrode tabs extend outwards from the housing and which includes one side wall and an opposite side wall arranged opposite each other with the in-situ coin cell interposed therebetween, and a temperature control unit coupled to the exterior of the housing and including an inlet port, an outlet port, and a flow passage.

Abstract: An apparatus and method for conducting a nail penetration test for a secondary battery are provided. The apparatus for conducting the nail penetration test includes: a stage on which the secondary battery, which is an object of the nail penetration test, is fixed; a nail penetration unit including a nail elevating/lowering means; a voltage measuring unit configured to repeatedly measure a short-circuit voltage of the secondary battery with a time interval during the nail penetration test; and a controller operably coupled to the voltage measuring unit. The controller periodically receives a short-circuit voltage from the voltage measuring unit, determines a short-circuit current allowing the received short-circuit voltage to be applied between outermost nodes of an equivalent circuit which models the secondary battery whenever the short-circuit voltage is received, and visually outputs a change in the determined value of the short-circuit current according to time through a display unit.

Abstract: A battery pack having a housing and a secondary battery inside the housing, and including a communicator that receives an instruction related to the secondary battery from an external communication terminal device via short-distance wireless communication and a controller that executes an operation in accordance with the instruction by using a status of the secondary battery. The external communication terminal device, by transmitting to the battery pack the instruction, which is related to the status of the secondary battery, acquires a response that is in accordance with the status of the secondary battery from the battery pack, thereby facilitating checking of secondary battery state.

Abstract: An electrical contact device includes a tubular element, a crown spring in the tubular element, a solid or hollow cylinder slideably received in the crown spring and a coil spring engaged with the cylinder for applying force while the cylinder is pressed against a test item and for returning the cylinder to a relaxed position. The crown spring holds the cylinder in the tubular element and allows the cylinder to slide back and forth while providing electrical connectivity between the cylinder and the tubular element. An electrical contact device includes a rod-shaped probe having a contact end and a contact sheet fixed to the probe, where the contact sheet has a plurality of prongs bent over the contact end of the probe for providing a plurality of contact points between the probe and a test item.

Abstract: Systems and methods for an open wire scan are provided. In certain embodiments, An apparatus comprising a circuit includes a plurality of inputs for connecting with a plurality of outputs of a multi-cell battery pack; and an open connection detection circuit, formed within the circuit, for detecting an open connection on at least one of the plurality of inputs connected to the multi-cell battery pack and generating a fault condition responsive thereto. The open connection detection circuit comprises at least one current source device; and at least one device for turning on and off the at least one current source device. The open connection detection circuit also comprises at least one amplifier; an analog to digital converter; and a control logic circuit.

Abstract: A method for locating a battery module among multiple battery modules of a traction battery that are electrically connected to one another, having the following features: an electrical potential is measured at each of the battery modules in real time relative to a potential reference that is common to the battery modules; the potentials are used to subtractively compute voltages between the battery modules; a positional relationship for the battery modules is derived from the voltages; a module controller that is univocally denoted within the traction battery is used to retrieve a voltage dropped across the battery module that is to be located; and the retrieved voltage and the computed voltages are used to locate the battery module on the basis of the positional relationship within the traction battery. Also described is a corresponding apparatus, a corresponding computer program and a corresponding storage medium.

Abstract: A magnetic sensor for measuring the magnetic properties of a battery cell, and converting the magnetic properties to a battery cell SOC. The magnetic sensor includes a magnetic core formed of laminated high permeability plates provided in a C-shape. An extended portion of the battery cell extends through a transverse opening in the core so that it is positioned within the core. A driving coil is wrapped around one end of the magnetic core and generates a magnetic field in the core that extends across the transverse opening and through the battery cell. A receiving coil is wrapped around an opposite end of the core that receives the magnetic field, and converts the magnetic field to a representative current. A detection circuit converts the receiving coil current to the battery cell SOC.

Abstract: A system and method for determining the health of a battery. A primary coil may be positioned along a first portion of a battery and a secondary coil may be positioned along a second portion of the battery. The primary coil may then be excited with a signal, and an electromagnetic field induced in the secondary coil by the excited primary coil may be measured. A state of health of the battery may thus correlate to the measured electromagnetic field during operation of the battery. This state of health may be determined as a function of electrolyte stratification, current profile, electrode structure, electrode surface degradation, and combinations thereof.

Abstract: A degradation determination device includes: a measuring unit measuring an open-circuit voltage characteristic indicating an open-circuit voltage variation with respect to a lithium ion secondary battery capacity variation; and a determining unit determining a degradation state due to wear and precipitation of lithium using a parameter for identifying the open-circuit voltage characteristic that substantially coincides with the measured open-circuit voltage characteristic.

Abstract: A method is provided for current-based detection of an electrical fault in an electrical network of a motor vehicle, the network having at least: one battery, one pulse-controlled inverter, one d.c. voltage converter, and an intermediate circuit associated with the pulse-controlled inverter. The method includes: detecting magnitudes of each a battery current, a d.c. voltage converter current, and an intermediate circuit current; comparing current magnitudes according to provided equations; and checking based on the comparison of whether a specifiable deviation has been exceeded. An alternative method for voltage-based detection of an electrical fault in an electrical network of a motor vehicle includes: detecting magnitudes of each a battery voltage, a d.c. voltage converter voltage, and an intermediate circuit voltage; comparing voltage magnitudes according to provided equations; and checking based on the comparison of whether a specifiable deviation has been exceeded.

Abstract: Methods, systems and structures for monitoring, managing electrolyte concentrations in redox flow batteries are provided by introducing a first quantity of a liquid electrolyte into a first chamber of a test cell and introducing a second quantity of the liquid electrolyte into a second chamber of the test cell. The method further provides for measuring a voltage of the test cell, measuring an elapsed time from the test cell reaching a first voltage until the test cell reaches a second voltage; and determining a degree of imbalance of the liquid electrolyte based on the elapsed time.

Abstract: A fuel cell system includes a fuel cell, a multiphase voltage conversion device with N-phases (N being an integer equal to or larger than two) that is connected to the fuel cell, a control signal generation portion that generates control signals to control each phase of the multiphase voltage conversion device by superimposing a control waveform for measuring impedance on a voltage indicating an output target voltage of the multiphase voltage conversion device and sequentially outputs the control signals corresponding to N phases with a predetermined phase difference to the multiphase voltage conversion device, and an impedance calculation portion that measures a current and a voltage of the fuel cell on cycles corresponding to N predetermined sampling frequencies having a phase difference equal to the predetermined phase difference and calculates an impedance of the fuel cell based on the measured current and the measured voltage.

Abstract: An MPU performs a degradation diagnosis based on an open circuit voltage characteristic of a rechargeable lithium ion battery indicating how the battery varies in open circuit voltage as the battery varies in capacity to obtain a capacity ratio of a positive electrode, a capacity ratio of a negative electrode, and a deviated capacity of the battery. The MPU applies the capacity ratio of the positive electrode and the capacity ratio of the negative electrode to a predetermined map for degradation attributed to wear to estimate a deviated capacity resulting from degradation attributed to wear and separates the deviated capacity into the deviated capacity resulting from degradation attributed to wear and a deviated capacity resulting from deposition of lithium. The MPU uses at least the deviated capacity resulting from deposition of lithium to determine whether a rechargeable lithium ion battery subject to determination of degradation is reusable and/or recyclable.

Abstract: The invention relates to a method for determining a state of health of an electrochemical device in particular having improved reliability. Said method in particular consists of: applying (10) to said electrochemical device an input signal comprising electrical excitations of different categories, and measuring an output signal (20) including the response signals to each electrical excitation; estimating (41) at least one first parameter from an electrical excitation belonging to a first category and the corresponding response signal; estimating (43) said at least one physicochemical parameter representative of the physicochemical behavior of the device from an electrical excitation of a different category, of the corresponding response signal and said first estimated parameter; estimating (50) said state of health of the electrochemical device as deviation between the previously estimated value of the physicochemical parameter and a reference value.

Abstract: An electrochemical test cell, containing an anode comprising a metal as an active component; a cathode comprising a porous chemically inert tube containing an active material compatible with the metal of the anode; and an electrolyte; wherein the only metal in contact with the electrolyte is the metal of the anode, is provided. This test cell is useful in a method to evaluate various combinations of materials for suitability as a combination for preparation of a battery.

Abstract: One exemplary embodiment includes a method including providing a battery, producing a first magnetic field so that a second magnetic field is induced in the battery, sensing a magnetic field resulting from the interaction of the first magnetic field and the second magnetic field, utilizing the sensed net magnetic field to determine the state of charge of the battery.

Abstract: One exemplary embodiment includes a method including providing a battery, producing a first magnetic field so that a second magnetic field is induced in the battery, sensing a magnetic field resulting from the interaction of the first magnetic field and the second magnetic field, utilizing the sensed net magnetic field to determine the state of charge of the battery.

Abstract: An apparatus comprises an integrated circuit and an open connection detection circuit within the integrated circuit. The integrated circuit includes a plurality of inputs for connecting with a plurality of outputs of a multi-cell battery pack. The open connection detection circuit within the integrated circuit detects an open connection on at least one of the plurality of inputs from the multi-cell battery and generates a fault condition responsive thereto.

Abstract: Provided is an insulation resistance measuring circuit including: a source resistor unit including a first source resistor connected between a positive terminal of a battery and a second source resistor and the second source resistor connected between a negative terminal of the battery and the first source resistor; a voltage sensing unit sensing a voltage of the first source resistor as a first voltage and sensing a voltage of the second source resistor as a second voltage; and an insulation resistance measuring unit measuring an insulation resistance of the battery through a value obtained by dividing a difference between the first and second voltages by a sum between the first and second voltages.

Abstract: An apparatus for monitoring battery voltage and temperature includes a host controller and acquisition boards, and every acquisition board for the battery includes a voltage acquisition module, a temperature acquisition module, a host control chip MCU, A/D convertor module, an opto-isolator module, a CAN bus communication module and two external connection ports CN1, CN2. The input end of the AD transformation module is connected with the output end of the voltage acquisition module and the temperature acquisition module, and the output end of the A/D convertor module is connected with the opto-isolator module via a SPI bus, and the I/O port of the SPI bus module in the main control chip MCU is connected with the opto-couple isolation module, and the host control chip MCU is connected with the CAN bus communication module of the host controller via the CAN bus communication module, and the acquisition boards are connected via a socket piece in turn.

Abstract: A measuring device is used in conjunction with a programmable controller for monitoring electrolyte levels in the battery. According to one implementation, the measuring device is located in a battery and is configured to detect when the electrolyte level in the battery falls below a particular level. The controller is in electrical communication with the electrolyte detection device. The controller is configured to: (i) receive a signal from the electrolyte level detection device indicating when the electrolyte level in the battery has fallen below the particular level; (ii) introduce a wait-period after the signal is received; and (iii) enable an indicator to indicate that the electrolyte level in the battery should be refilled when the wait-period expires.

Abstract: Modeling and testing are used to characterize consequences of a first lithium-ion cell having an internal short. The vulnerability of a second lithium-ion cell being induced into thermal runaway by the energy released by the first cell undergoing an internal short is quantified. Characteristics of the packaging of Li-ion cells within a battery pack are analyzed. Combined, these analyses determine the robustness required of a cell in order to withstand a nearby cell's internal short given that the battery is maintained within the specified operational envelope by a BMS and this envelope is modified in real-time as required to meet the safety requirement. Robustness factors are: age, history of charging/discharging, as well as immediate state of charge and environment. In operation, the cell's operational history is incorporated into a model. When the model indicates cell robustness at a predetermined lower limit, operation of the cell is ceased or limited.

Abstract: A battery confirmation system and method for confirming a state of charge in a vehicle battery installed in a vehicle includes a vehicle having a controller, a battery powering the controller, and an onboard diagnostics connector operatively connected to the controller. A tester is connectable to the onboard diagnostics connector. The tester is configured to receive a vehicle operating voltage from the connector when an electrical load on the battery is within a predetermined load range and to determine a SOC value based on the vehicle operating voltage.

Abstract: Systems and methods for monitoring a voltage pump to determine the status of a battery connected to the voltage pump are provided. The operation of the voltage pump is monitored during at least one monitoring period which corresponds to a period of relatively heavy consistent load. The operation of the voltage pump can be monitored by sampling a control signal that corresponds to the operation of the voltage pump.

Abstract: Vehicle maintenance circuitry for use with a storage battery, and/or electrical system of a vehicle includes an electrical connector configured to electrically couple to the vehicle. OBD communication circuitry is configured to couple to an OBD databus of a vehicle. The operation of the vehicle maintenance circuitry is a function of communication on the OBD databus.

Abstract: A fuel cell system includes a fuel cell; a voltage measuring portion that measures a voltage of the fuel cell; an electric current adjusting portion that adjusts an electric current flowing in the fuel cell; an electric current-voltage characteristic information obtaining portion that controls the electric current adjusting portion to change the electric current, and obtains electric current-voltage characteristic information that is information indicating a correspondence relation between an electric current value and a voltage value measured by the voltage measuring portion; and a negative voltage cause determining portion that determines, if the voltage of the fuel cell is a negative voltage, a cause of the negative voltage of the fuel cell, based on the obtained electric current-voltage characteristic information.

Abstract: A system and method for controlling a power storage device through the Stimulation and Intensification of Interfacial Processes (SIIP) is provided. A signal generator can provide a low voltage sinusoidal AC signal across a battery terminal, or other reactor vessel, during charging and discharging states. For example, the battery/reactor vessel can be of Li-ion and NiMH designs, a fuel cell, a Zn—O cell, or other devices that have features of rechargeable batteries. The output of the signal generator (i.e., voltage, wave type, and frequency) can be controlled based on battery parameters (e.g., internal resistance, output power, temperature). The internal resistance of the battery can be reduced, and the discharge time can be increased. Elastic waves can also be provided to a battery/reactor vessel to stimulate the interfacial processes. The signal generator can be an integrated circuit which is packaged with the battery and can be powered by the battery.

Abstract: A battery pack includes: one or two or more secondary batteries; a charge control switch that turns on/off a charging current to the secondary battery; a discharge control switch that turns on/off a discharging current from the secondary battery; a current-detecting element for detecting the charging current and the discharging current; a voltage measuring part that measures the voltage of the secondary battery; a control unit that controls the charge control switch and the discharge control unit; and a storage unit that stores an initial internal resistance of the secondary battery. The control unit measures a closed circuit voltage and a charging current during charging, and a first closed circuit voltage after a first waiting time and a second closed circuit voltage after a second waiting time. The second waiting time is longer than the first waiting time.

Abstract: In an ion elution unit, a drive circuit applies a voltage between electrodes to elute metal ions from the electrodes. Polarities of the electrodes are reversed cyclically with a voltage application halt period placed in-between. A current detection circuit detects the current flowing between the electrodes. A check of operation of the current detection circuit is carried out before the application of a voltage to the electrodes is started. The operation of the current detection circuit is started when a predetermined period of time passes after the application of a voltage to the electrodes is started.

Abstract: There is provided an apparatus that calculates a polarization voltage of a secondary battery. A temperature sensor detects a temperature of the secondary battery; a voltage sensor detects a voltage of the secondary battery; and a current sensor detects an electric current of the secondary battery. A battery ECU calculates a polarization voltage based on the electric current and adaptively sets an upper limit value and a lower limit value of the polarization voltage according to a temperature characteristic of the secondary battery. The calculated polarization voltage is compared with an upper limit value and a lower limit value, whereby the polarization voltage is corrected. An SOC is estimated based on the corrected polarization voltage.

Abstract: Methods, systems and structures for monitoring, managing electrolyte concentrations in redox flow batteries are provided by introducing a first quantity of a liquid electrolyte into a first chamber of a test cell and introducing a second quantity of the liquid electrolyte into a second chamber of the test cell. The method further provides for measuring a voltage of the test cell, measuring an elapsed time from the test cell reaching a first voltage until the test cell reaches a second voltage; and determining a degree of imbalance of the liquid electrolyte based on the elapsed time.

Abstract: A system for testing a DC power supply performance includes a load module electrically coupled to the DC power supply, a switch module electrically coupled to the DC power supply, a control module electrically coupled to the load module and the switch module respectively, and an indication module electrically coupled to the control module. The control module includes a judge module and a comparison module. The judge module is configured for receiving DC voltage signals from the DC power supply; wherein the judge module is capable of turning on when the DC power supply is normal. The comparison module is configured for comparing the DC voltage signals with a reference voltage; wherein the comparison module is capable of outputting a control signal when the DC voltage signals are greater than the reference voltage. The indication module is configured for receiving the control signal and indicating status of the DC power supply.

Abstract: A method of testing a battery including several steps described herein is provided.

Abstract: A battery tester determines a remaining level of charge of a battery mounted within a separate electronic device having an audio jack. The battery tester includes a plug and a circuit having a high impedance input amplifier. At least one electrical contact of the plug is electrically coupled to an input of the high impedance input amplifier. The plug is removably insertable within the audio jack such that the battery of the separate electronic device is electrically connected to the input of the high impedance input amplifier. When electrically coupled to the battery, an output of the high impedance input amplifier provides a signal proportional to the remaining level of charge of the battery, whereby the remaining level of charge of the battery is obtainable by the battery tester without having to remove the battery from the electronic device.