7996 results about "Internal resistance" patented technology

Improvements both in the methods whereby existing techniques for determining the condition of a battery are communicated to a user (for example, to the owner of a private vehicle, or to the service manager of a fleet of vehicles), or the vehicle's operating system, and in the methods for evaluating the condition of the battery are disclosed. It has been discovered by the inventors that the difference in internal resistance of a fully charged battery as measured during charging and as measured after charging is greater for a battery in poor condition than for a new battery. The invention relates in part to instruments and corresponding methods for evaluating the condition of a battery utilizing this discovery.

Disclosed are a laminated lithium ion battery, a battery pack comprising the same and a pole piece of the laminated lithium ion battery. The pole piece comprises a current collector and an active material layer, wherein the current collector is coated with the active material layer. A section of continuous uncoated area is arranged at the tail end of a first width end portion of the pole piece, the top face and the bottom face of the uncoated area are not coated with the active material layer, the current collector is exposed in the uncoated area, and the exposed current collector serves as a pole lug of the pole piece. By the pole piece, internal resistance of the lithium ion battery is reduced and heat dissipation performance of the battery is improved.

A main power source (2) is, for example, an ordinary Pb battery and generates a voltage of 12-13 V. At the time of starting an engine, the main power source (2) supplies power to a starter (8a). The main power source (2) is given a higher priority than an auxiliary power source (3) to supply power to ordinary loads (8b). The auxiliary power source (3) is a high performance battery (e.g., Li ion battery), which has superior charge acceptance capability and better state detectability over the main power source (2). Furthermore, the auxiliary power source (3) has an internal resistance per unit capacity, which is smaller than that of the main power source (2), and generates a voltage of 9-12 V. A generator (1) is directly connected to the auxiliary power source (3). The auxiliary power source (3) stores regenerative power, which is generated by the generator (1) at the time of deceleration of a vehicle, and is used as a redundant power source for the main power source (2). The main power source (2) and the auxiliary power source (3) are connected to each other through a supply circuit (5), which has a DC / DC converter (4), and a second supply circuit 7, which has a switch (6).

The invention discloses a method for detecting the electrical property consistency of lithium ion battery. The method comprises the following steps of: performing formation storage and ageing storage on a plurality of monomer batteries for a long time one by one and selecting the battery with large self discharge; performing capacity grading treatment on the rest of qualified monomer batteries to obtain the actual battery volume C of the plurality of monomer batteries, charging the plurality of monomer batteries to the same charging state and classifying the plurality of batteries according to the volume difference standard; performing low-temperature direct-current internal resistance test on the plurality of batteries with the same volume difference standard grade and reclassifying the battery according to the direct-current internal resistance of the battery; and selecting and matching the plurality of batteries in the same direct-current internal resistance grade to form the battery pack. The invention can detect the electrical property consistency of the lithium ion battery under the low-temperature condition, effectively solve the problem that the battery has good electrical property consistency under the normal-temperature condition and differed electrical property consistency under the low-temperature condition and is suitable for detecting a batch of batteries and selecting qualified monomer batteries to form a battery pack.

A power source apparatus mounted to a vehicle is equipped with a lead-acid battery and a lithium battery. An open circuit voltage and an internal resistance of each of the batteries are determined to satisfy the following conditions (a1), (a2), and (a3): (a1) In the use range of SOC of the lead-acid battery and the use range of SOC of the lithium battery, there is an equal voltage point Vds at which the open circuit voltage V0 (Pb) of the lead-acid battery becomes equal to the open circuit voltage V0 (Li) of the lithium battery; (a2) The relationship of V0 (Li)>V0 (Pb) is satisfied in the upper limit side of the use range of SOC of the battery; and (a3) A terminal voltage Vc (Li) of the lithium battery is not more than a set voltage Vreg of a regulator when a maximum current flows in the lithium battery.

The invention discloses a method for estimating battery health of an electric automobile, which relates to methods for estimating battery health according to voltage characteristics of a battery charging end. The method solves the defect that battery parameters, such as impedance, internal resistance and the like, need to be calculated while estimating battery health in the prior art. The method is used for estimating battery health. The method comprises the following steps of: emptying a new battery to be detected, and fully charging the new battery to be detected, and in the fully charging process, recording a voltage-time curve and a charge capacity-time curve of charging of the new battery to be detected; calculating actually usable capacity Qnew of the new battery to be detected; setting a threshold of V / dQ; calculating the charged capacity of the new battery to be detected from the time when the threshold of dV / dQ is realized to the time when the battery is fully charged during the charging process; building a relation curve of the open-circuit voltage and SOC (State Of Charge) of the new battery to be detected; estimating a SOCocv, then, calculating theoretically usable capacity Qtest-full of the attenuated battery; and obtaining the health of the battery to be detected according to the attenuated theoretically usable capacity QoId and the actually usable capacity Qnew of the battery.

The invention provides a combined estimation method for lithium ion battery state of charge, state of health and state of function. The combined estimation method comprises the steps that the state of he---alth of a battery is estimated online: open circuit voltage and internal resistance are identified online by adopting a recursive least square method with a forgetting factor, the state of charge is indirectly acquired according to a pre-established OCV-SOC corresponding relation, and then the size of battery capacity is estimated according to cumulative charge and discharge electric charge between two SOC points; the state of charge of the battery is estimated online: the state of charge of the battery is estimated by adopting the Kalman filter algorithm based on a two-order RC equivalent circuit model, and the battery capacity parameter in the Kalman filter algorithm is updated according to the estimation result of battery capacity; and the state of function of the battery is estimated online: the maximum chargeable and dischargeable current is calculated based on the voltage limit and the current limit of the battery according to internal resistance obtained by online identification, and then the maximum chargeable and dischargeable function can be obtained through further calculation.

The invention discloses an SOC (State of Charge) and SOH (State of Health) prediction method of an electric vehicle-mounted lithium iron phosphate battery, which comprises the following steps of: (a) improving a Thevenin cell equivalent model; (b) determining the state equation and the output equation of a system; (c) identifying battery model parameters; (d) using a Kalman filter algorithm to iterate the state variables of the system, so that the predictive value of SOC is closer to the actual value; and (e) using a dual-channel Kalman filter algorithm to carry out the online predication of an internal resistance and capacity of the lithium iron phosphate battery, and simultaneously predicating the SOH of the battery according to the changes in the internal resistance and the capacity value of the battery in the current state and the initial state. With the method, the predication precision of SOH of the battery is effectively improved, the decline in battery performance can be determined more accurately, and the internal resistance and capacity information of the battery is combined to provide a basis for making the battery management strategy and maintaining and replacing the battery.

An electrical storage device of the present invention is characterized in that a positive electrode, a negative electrode, a lithium electrode, and an electrolyte capable of transferring lithium ion is included, the lithium electrode is arranged to be out of direct contact with the negative electrode, and lithium ion can be supplied to the negative electrode by flowing a current between the lithium electrode and the negative electrode through an external circuit. With the above characteristic, problems such as non-uniform carrying of lithium ion to the negative electrode, shape-change of a cell, and temperature increase of an electrolytic solution under incomplete sealing of a cell and the like can be easily solved. A using method of the electrical storage device is characterized in that, by using the lithium electrode as a reference electrode, the positive electrode potential and negative electrode potential can be measured, and the potential of the positive or negative electrode can be controlled when the electrical storage device is charged or discharged. Therefore, the potentials of the positive electrode and negative electrode can be monitored, thereby it can be easily determined whether deterioration of the electrical storage device is caused by the positive electrode or the negative electrode. Also, it is possible to control the device with the potential difference between the negative electrode and reference electrode, that is, the negative potential. In addition, when characteristics deteriorate such as the internal resistance increase, an appropriate amount of lithium ion can be supplied to the negative electrode and / or positive electrode by the lithium electrode.

A method for determining deterioration of accumulator battery hooked up with loads in a system based on results of measuring internal resistances of an accumulator battery, the method comprising the steps of; predetermining as a specified temperature a temperature at which the deterioration of the accumulator battery is determined; calculating in advance temperature correction coefficients of the internal resistances from changes of the internal resistances depending on temperatures; predetermining resistance-voltage conversion factors to convert between the internal resistances at the specified temperature and terminal discharge voltages of the accumulator battery which are obtained at the specified temperature under a condition of flowing predetermined discharge currents from the accumulator battery; measuring the internal resistances of the accumulator battery and temperature of the accumulator battery at an internal resistance measurement; converting the measured internal resistance values into the internal resistance values at the specified temperature with use of the temperature correction coefficients of the internal resistances; converting the internal resistance values at the specified temperature into the terminal discharge voltage values of the accumulator battery at the specified temperature with use of the resistance-voltage conversion factors; and determining whether the accumulator battery is deteriorated or not by means of comparison of the terminal discharge voltage values of the accumulator battery at the specified temperature and a predetermined threshold value as a deterioration judgment standard.

This invention measures the exact value of impedance voltage (Vis) from AC actual waveform (VSM) which includes ripple noise voltage, and suggests the inventive circuits and softwares capable of acquiring the effective resistance of battery internal impedance and the operational algorithm of the diagnosis for the expected life of battery string. In accordance with a series of functional operations and the execution of the program in MPU, this diagnostic system can find the cause of aging progress in advance and settle by unmanned monitoring the healthiness of emergency power system always in real time at remote site.

A system for providing an accurate indication of the remaining life of a battery. The system includes a first circuit that provides a control signal. A second circuit employs an internal resistance value of the battery and a battery voltage to provide the indication of remaining battery life in response to the control signal. In a specific embodiment, the second circuit includes a third circuit that measures the internal resistance of the battery in response to the control signal. The third circuit also includes a circuit for measuring an output current and an output voltage of the battery at varying battery loads. The circuit for measuring an output current includes an ammeter and a switching load. In a more specific embodiment, the switching load is implemented as a transmitter that is selectively activated via the control signal. A fourth circuit, included in the second circuit, provides the indication of remaining battery life in response to the internal resistance. The fourth circuit also includes a circuit for selecting a battery discharge curve in accordance with the internal resistance. Software running on the first circuit generates the estimate based on the discharge curve, which is subsequently displayed via a display.

When a current flows through a battery, a resistance loss proportional to the square of the current is produced by an internal resistance component of the current. In a case where the temperature of a heat capacity element is raised, a charging current is controlled such that prescribed thermal energy is provided to the heat capacity element by this resistance loss. Air is induced into a power supply unit through a vehicle compartment air exhaust duct. Then, the thermal energy stored in the heat capacity element is transferred to the air induced into the power supply unit. The air to which the thermal energy has been provided from the heat capacity element is blown out toward a vehicle compartment space by a fan.

The invention provides a multi-element composite nano-material for a super capacitor, and a preparation method of the nano-material. The nano-material comprises a carbon material, metal oxide and conducting polymer, and components of the nano-material can be two or more than two materials. By the aid of the characteristics such as fine electrical conductivity, long cycle life and high specific surface area of the carbon material, high pseudo-capacitance of the metal oxide and low internal resistance, low cost and high operating voltage of the conducting polymer, different types of electrode materials generate synergistic effects, advantages are mutually combined, shortcomings are mutually weakened, the energy storage characteristics of an electric double-layer capacitor and a pseudo-capacitor are simultaneously made full use of, a composite electrode material with high power density, fine circulating stability and higher energy density is prepared, and the multi-element composite nano-material is excellent in comprehensive performance when used for an electrode of the super capacitor, has the advantages of simple preparation process, short cycle, low cost and the like, and is suitable for large-scale industrial production.

The electrode of the present invention is provided with an active material-containing layer comprising as the structural material composite particles composed of an electrode active material, a conductive additive and a binder, and a current collector in electrical contact with the layer. The composite particles are formed by integrating the conductive additive and binder with the electrode active material particles. The active material-containing layer is formed by subjecting powder comprising at least the composite particles to pressurization treatment to form a sheet, and placing the sheet at the location of the current collector at which the active material-containing layer is to be formed. The electrode active material and conductive additive in the active material-containing layer are non-isolated and electrically linked. This construction allows an electrode with excellent electrical characteristics to be realized, which exhibits adequately reduced internal resistance and easily permits increased energy density to be achieved for electrochemical devices.

The present invention discloses a control device and method for over current or short circuit protection of electronic cigarette. The control device includes an input module, a power module, a heating element, a switch control module, a comparator, and a FET; the FET is used to detect an operating voltage generated by an operating current following through the internal resistance of the FET, and the operating voltage is transmitted to the comparator; the comparator compares a reference voltage with the operating voltage, and output a potential signal to the switch control module, the switch control module turns off the FET or maintains it turning on corresponding to the potential signal, further the FET powers off or powers on the heating element. Therefore the circuit of electronic cigarette is protected in over current or short circuit condition.

The present invention provides an electrode made of carbon nanotubes or carbon nanofibers and a process for preparing the same. The electrode comprising a current collector, sulfur or metal nanoparicles as a binder, and carbon nanotubes or carbon nanofibers is characterized in that the sulfur or metal nanoparticles are bonded, deposited, or fused on the surfaces of the carbon nanotubes or carbon nanofibers so that the carbon nanotubes or carbon nanofibers are bonded to each other and also bonded to the current collector. The electrode prepared according to the present invention exhibits low internal resistance, strong durability and low equivalent series resistance, and therefore the electrode can be effectively used for secondary batteries, supercapacitors or fuel cells.

Improvements both in the methods whereby existing techniques for determining the condition of a battery are communicated to a user (for example, to the owner of a private vehicle, or to the service manager of a fleet of vehicles), or the vehicle's operating system, and in the methods for evaluating the condition of the battery are disclosed. It has been discovered by the inventors that the difference in internal resistance of a fully charged battery as measured during charging and as measured after charging is greater for a battery in poor condition than for a new battery. The invention relates in part to instruments and corresponding methods for evaluating the condition of a battery utilizing this discovery.

The invention discloses a lithium ion battery internal temperature monitoring method. The monitoring method includes the following steps that a charge-discharge tester is used for carrying out charge-discharge tests on a lithium ion battery on different environment conditions to obtain a battery surface temperature change curve; related parameters such as battery internal resistance and an open-circuit voltage temperature coefficient are tested, and a lithium ion battery electric heating coupling model based on a variable heat production rate is set up; the temperature rise change of the discharge process of the battery is simulated to obtain a temperature change simulation curve; the experiment test temperature change curve and the simulation curve are analyzed and compared to optimize and verify the electric heating coupling model; the influence between the battery internal temperature and the battery surface temperature as well as the influence between the discharge currents and the discharge depth are analyzed, and a lithium ion battery internal temperature model is constructed; the battery internal temperature is monitored in real time according to the model. The lithium ion battery internal temperature monitoring method is simple and easy to implement, small in estimation error and capable of well meeting the requirement for monitoring the battery internal temperature in real time.

Disclosed is a method and apparatus of estimating a state of health (SOH) of a battery using internal resistance, which has been found to act as a parameter exerting the greatest influence on the SOH of the battery. The method comprises the steps of: storing an SOH estimation table constructing SOH values corresponding to various values of internal resistance according to temperature and a state of charge (SOC) in a memory; performing measurement of the temperature and estimation of the SOC of the battery when a request is made to estimate the SOH; detecting the internal resistance value of the battery; and reading the SOH values corresponding to the measured temperature, the estimated SOC of the battery, and the detected internal resistance value of the battery from the SOH estimation table.

A battery management system and a driving method thereof includes a sensing unit and a micro control unit (MCU). The sensing unit measures a battery temperature and a battery current. The MCU receives the battery temperature and current, detects battery internal resistance corresponding to an estimated state of charge (SOC) and the battery temperature when the estimated SOC is included within an SOC area corresponding to the transmitted battery temperature, and estimates a battery state of health (SOH) by using the battery internal resistance. In the SOC area, a variation of the battery internal resistance is minimized.

The invention relates to a novel carbon-sulfur compound for an anode material of a lithium-sulfur battery and a preparation method thereof. Sulfur is filled into a nano and micron hole of a matrix in an elementary substance way by taking a macroporous carbon material with high pore volume, electrical conductivity and specific surface area as the matrix, and the sulfur and carbon can also carry out combination reaction so as to prepare the novel carbon-sulfur compound of which the sulfur exists in one or more chemical states in a carbon material. The novel carbon-sulfur compound used as the anode material of the lithium-sulfur battery has the advantages that the high pore volume has large contained sulfur contents and can ensure high electric capacity; the small granularity of the sulfur can reduce a conductive distance between ions and electrons and increase the utilization ratio of the sulfur; and the adsorption characteristics of the high specific surface of the carbon material can inhibit a discharging intermediate product from dissolving and moving towards a cathode, reduce the self discharge, prevent a nonconductive discharging product, namely lithium sulfide from largely accumulating outside carbon particles and reduce internal resistance, therefore, the material can improve the specific energy, the specific power and the cycle performance of the lithium-sulfur battery.

A battery ECU estimates the SOC by integrating the battery current measured by a current sensor, and the battery voltage Vn is measured by a voltage sensor and the battery temperature Tn is measured by a thermometer if the fluctuation of the charging / discharging current is great. If the number m of estimations of SOCn is m<10, m is incremented. The battery internal resistance Rn is estimated from the measured battery temperature Tn by using a correlation map showing the correlation between the previously stored battery temperature T and the battery internal resistance R. An estimation charging / discharging current In is determined using the measured battery voltage Vn, the battery open voltage Vocvn−1 determined on the basis of the previously estimated charged state, and the estimated battery internal resistance Rn. The SOCn is estimated by integrating the estimated charging / discharging current In. If the number m of estimations of the SOCn is m=10, the number m of estimations is changed to 0. The charging / discharging current in is measured by a current sensor. The battery internal resistance Rn is calculated from the battery voltage Vn and the charging / discharging current in. The battery temperature Tn is also measured, and the T-R correlation map is corrected.

A method comprises coupling a first power transistor as a first external load in series with the battery, coupling a second power transistor as a second external load in series with the battery, conducting each power transistor to supply a transient large current to the battery for sampling a group of sampled reference voltages and sampled load voltages in a very transient sampling time for a plurality of times and thus obtaining an internal resistance of the battery. The internal resistance of the battery can then be compared with a predetermined warning value thereof so as to determine whether the former is equal to or larger than the warning value or not, and issuing a warning through an I / O if the determination is affirmative. The invention enables a driver to correctly know the actual condition of the battery in substantially real time while consuming a minimum amount of power.

An active implantable medical device, in particular a pacemaker, defibrillator or cardioveter of the multisite type, including a circuit for measuring intercardiac impedance. Electrodes are placed in at least one ventricular site and one atrial site, and are connected to a circuit for the collection of cardiac signals, to detect a depolarization potential, as well as to a stimulation circuit, to apply stimulation pluses to at least some of the aforementioned sites. The measurement of a trans-pulmonary bio-impedance is obtained by injecting a current from an injection circuit (16) between the case (18) of the device and a first atrial (RA-) (or ventricular) site, and measuring a differential potential (20) between the case (18) and a point of measurement located in a second atrial (RA+) (or ventricular) site using a collection circuit. Switches are selectively operable to isolate the case (18) from the current injection and measurement of potential circuits, and to connect them to a common reference potential site, atrial or ventricular (LV-), which is distinct from the sites (RA-,RA+) to which are also connected these circuits, so as to allow a measurement of intracardiac impedance from the signal delivered by the differential potential measuring circuit. The switching is obtained by connections to an electric ground, operating independently of the current injection circuit and the differential potential measuring circuit.

A method of using data-driven predictive modeling to predict and classify battery cells by lifetime is provided that includes collecting a training dataset by cycling battery cells between a voltage V1 and a voltage V2, continuously measuring battery cell voltage, current, can temperature, and internal resistance during cycling, generating a discharge voltage curve for each cell that is dependent on a discharge capacity for a given cycle, calculating, using data from the discharge voltage curve, a cycle-to-cycle evolution of cell charge to output a cell voltage versus charge curve Q(V), generating transformations of ΔQ(V), generating transformations of data streams that include capacity, temperature and internal resistance, applying a machine learning model to determine a combination of a subset of the transformations to predict cell operation characteristics, and applying the machine learning model to output the predicted battery operation characteristics.

The invention discloses a method for evaluating lithium ion battery peak power online. The method comprises the following steps that influencing characteristic curves of the influence on lithium ion battery peak power by the charge state, Ohm internal resistance, temperature and sustainable time of a lithium ion battery are respectively built; all factors influencing the battery peak power are synthesized, and a battery peak power evaluation initial model is built; the battery peak power evaluation initial model is embedded into a vehicle-mounted terminal system, and the battery peak power evaluation initial model continues to be trained. The method has the advantages that the situations that due to the fact that the operation is not proper, and the battery is overcharged or overdischarged, the service life of the battery is shortened, and use cost is greatly increased are basically avoided through the method, the danger coefficient of the battery in the use process is lowered, and the reliability and stability of the operation of an electric vehicle are improved, and personal safety and equipment safety are guaranteed.

Limit values of battery charging and discharging power are set by a battery charge discharge control apparatus, based on the estimation of the internal resistance of a battery according to a detected battery temperature and the sampling of a battery current and a battery voltage respectively detected by a current sensor and a voltage sensor. The limit values are used to control the battery current and the battery voltage to be within a current use range and a voltage use range of the battery, according to conditions of the battery in a vehicle.

An ECU in an automatic engine control device predicts a maximum discharging current to be supplied from a battery to a starter during a next restart of the engine based on a present voltage, an internal resistance value of the battery, and a starter total resistance value during automatic engine stop. The ECU further predicts a minimum voltage of the battery during a period until the next restart of the engine based on the present voltage, the present internal resistance value of the battery, and the predicted maximum discharging current. The ECU judges whether or not execution of the next restart of the engine during the automatic engine stop based on the predicted minimum voltage of the battery.