13754 results about "Charge and discharge" patented technology

A method of producing a diode drive current in an oximeter includes sensing at least a part of a current passing through the diode and converting the sensed current to a sensed voltage, inputting the sensed voltage to a feedback amplifier for stabilizing the current passing through the diode, and eliminating an offset voltage across inputs of the feedback amplifier. A pulse oximeter includes a diode for emitting light flashes, a feedback amplifier having inputs, a feedback capacitor, and an output, the feedback amplifier stabilizing a current passing through the diode, a nulling amplifier having inputs, a nulling capacitor, and an output, the nulling amplifier charging and discharging the feedback capacitor until the inputs of the feedback amplifier are at a same voltage. The operation may include synchronizing an elimination of input offset voltages of the feedback and nulling amplifiers with on or off state of diode current.

A cordless instrument (20, 40) detachable from a charger (10, 30, 31) is attached to the charger (10, 30, 31), and is charged. A first storage part (12, 33) chargeable from a direct current source (11, 32) included in the charger (10, 30, 31), a first charge and discharge control circuit (13, 50) to control charge and discharge of the first storage part (12, 33), a second storage part (21, 43) included in the cordless instrument (20, 40), and a second charge and discharge control circuit (22, 45) to control charge and discharge of the second storage part (21, 43) are provided. Further, a third storage part (28) chargeable from the direct current source (11, 32) may be provided. Also to the cordless instrument (20, 40), a fourth storage part (44) may be provided. Upon attaching the cordless instrument, the second storage part (21, 43) is charged at least from the first storage part (12, 33). In comparison with charging time to conventional secondary batteries, it is capable of rapid charge, long life use, resulting in such merits as to realize the compact size of a charger and low cost.

A nano graphene-enhanced particulate for use as a lithium-ion battery anode active material, wherein the particulate is formed of a single sheet of graphene or a plurality of graphene sheets and a plurality of fine anode active material particles with a size smaller than 10 μm. The graphene sheets and the particles are mutually bonded or agglomerated into the particulate with at least a graphene sheet embracing the anode active material particles. The amount of graphene is at least 0.01% by weight and the amount of the anode active material is at least 0.1% by weight, all based on the total weight of the particulate. A lithium-ion battery having an anode containing these graphene-enhanced particulates exhibits a stable charge and discharge cycling response, a high specific capacity per unit mass, a high first-cycle efficiency, a high capacity per electrode volume, and a long cycle life.

In an exemplary embodiment, a battery conditioning system monitors battery conditioning and includes a memory for storing data based thereon; for example, data may be stored representative of available battery capacity as measured during a deep discharge cycle. With a microprocessor monitoring battery operation of a portable unit, a measure of remaining battery capacity can be calculated and displayed. Where the microprocessor and battery conditioning system memory are permanently secured to the battery so as to receive operating power therefrom during storage and handling, the performance of a given battery in actual use can be accurately judged since the battery system can itself maintain a count of accumulated hours of use and other relevant parameters. In the case of a nonportable conditioning system, two-way communication may be established with a memory associated with the portable unit so that the portable unit can transmit to the conditioning system information concerning battery parameters (e.g. rated battery capacity) and/or battery usage (e.g. numbers of shallow discharge and recharge cycles), and after a conditioning operation, the conditioning system can transmit to the portable unit a measured value of battery capacity, for example. A battery pack having memory stores battery history and identifying data to be retrieved by a portable battery powered device. Battery status information may be utilized in conjunction with characteristic battery history data in order to optimize charging and discharging functions and to maximize the useful life of a battery pack.

A method of providing closed-loop control of power flowing into and out of an energy storage system (ESS), wherein the ESS comprises a battery is provided. The method may be implemented as a computer control algorithm for determining the charge and discharge limits for the ESS in a hybrid electric vehicle (HEV), wherein the ESS comprises a battery pack or array. The method comprises determining charge and discharge power limits during each of a plurality of control loops, comparing these limits during each of the plurality of control loops, and providing a charge power limit output and a discharge power limit output for use in a subsequent control loop which are based upon the charge power limit and the discharge power limit. The charge power limit output and discharge power limit output are set equal to the discharge power limit and charge power limit, respectively, when the discharge power limit is greater than the charge power limit; and are selected from the group consisting of the charge power limit, the discharge power limit and zero when the discharge power limit is less than or equal to the charge power limit.

A dynamic memory circuit in which the inherent bipolar transistor effect within a floating body transistor is utilized to store an information bit. A floating body of a storage transistor stores an information bit in the form of an electric charge. The floating body is charged and discharged via an access transistor during data write operations. The inherent bipolar transistor resident within the floating body transistor increases the effective capacitance of the floating body which acts as the storage node, and thereby enhances the magnitude of the discharge current which represents the stored information bit during read operations.

Electrochemical cells, and more specifically, rechargeable batteries comprising lithium anodes for use in water and/or air environments, as well as non-aqueous and non-air environments, are presented. In one embodiment, an electrochemical cell includes an anode comprising lithium and a multi-layered structure positioned between the anode and an electrolyte of the cell. A multi-layered structure can include at least a first single-ion conductive material layer (e.g., a lithiated metal layer), and at least a first polymeric layer positioned between the anode and the single-ion conductive material. The invention also can provide an electrode stabilization layer positioned within the electrode, i.e., between one portion and another portion of an electrode, to control depletion and re-plating of electrode material upon charge and discharge of a battery. Advantageously, electrochemical cells comprising combinations of structures described herein are not only compatible with environments that are typically unsuitable for lithium, but the cells may be also capable of displaying long cycle life, high lithium cycling efficiency, and high energy density.

In order to charge and discharge parasitic capacitance of a source signal line sufficiently and program a predetermined current value into a pixel transistor, it is necessary to output a relatively large current from the source driver circuit.

However, if such a large current is passed through the source signal line, the value of this current is programmed into the pixel, causing a larger than desired current to flow through an EL element 15.

For example, if a 10 times larger current is used for programming, a 10 times larger current flows through the EL element 15, and thus the EL element 15 illuminates 10 times more brightly. To obtain predetermined emission brightness, the time during which the current flows through the EL element can be reduced to 1/10 of one frame (1 F). This way, the parasitic capacitance of the source signal line can be charged and discharged sufficiently and the predetermined emission brightness can be obtained.

A system and method for digital management and control of power conversion from battery cells. The system utilizes a power management and conversion module that uses a CPU to maintain a high power conversion efficiency over a wide range of loads and to manage charge and discharge operation of the battery cells. The power management and conversion module includes the CPU, a current sense unit, a charge/discharge unit, a DC-to-DC conversion unit, a battery protection unit, a fuel gauge and an internal DC regulation unit. Through intelligent power conversion and charge/discharge operations, a given battery type is given the ability to emulate other battery types by conversion of the output voltage of the battery and adaptation of the charging scheme to suit the battery.

A power converter includes a DC to AC inverter that is connected to a neutral node formed between first and second capacitors connected across two DC supply lines. The inverter is operated to selectively couple the DC supply lines and the neutral node to an output terminal thereby producing an alternating voltage waveform formed by a sequence of output pulses having positive, zero and negative voltage levels. To compensate for a voltage imbalance across the capacitors, an imbalance compensation coefficient is derived from the difference in voltages across the first and second capacitors and from the direction of current between the neutral node and the inverter. The imbalance compensation coefficient is employed to adjust the width of the output pulses so as to charge and discharge the capacitors to correct the imbalance.

A battery management unit and system for managing the state of charge of cells or batteries (B1-B10). Each battery management unit (1) measures cell or battery terminal voltage and provides this information to a central controller (3) via a communication medium (2). Each battery management unit (1) monitors a plurality of batteries (B1-B10) and can selectively charge a selected battery (B1-B10) via a charger (7) and switch circuit (8, 17) or can selectively discharge a selected battery (B1-B10) via a load (10) and switch circuit (8, 17) under the control of a controller (6). The controller (6) may control charging and discharging in accordance with measurements from voltage sensors (15a-j) or may convey information from a voltage sensors (15a-15j) to the central controller (3) and receive charging and discharging commands from the central controller (3). Charging and discharging is controlled to maintain all batteries within a desired state of charge ranged. The central controller (3) may selectively connect a main charger (20) or generator (21) to a bank of batteries associated with a battery management unit (1).

Positive electrode active materials are described that have a very high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_βCO_γO₂, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the cell. Methods for producing these materials include, for example, a co-precipitation approach involving metal hydroxides and sol-gel approaches.

A method of providing power to an electronic device in an energy-efficient manner includes transitioning between power states corresponding to charging and discharging a battery. The state of charge of the battery is detected. Upon detecting a high threshold state of charge, an external power source such as an AC-to-DC adapter is disabled, and the battery to provides primary power to the electronic device. Upon a low threshold state of charge, the AC-to-DC adapter is controlled to provide a high current output to charge the battery and provide primary power to the electronic device. The power states, when cycled over time based on the state of the battery, provide for an energy-efficient method of powering the electronic device.

A circuit for rendering an energy storage device parallelable comprised of an energy storage device connected to a power adapter that converts the potential of the energy storage device into a potential that follows a predetermined function of the state of charge of the energy storage device. When multiple assemblies are paralleled, they may be charged and discharged as a whole with individual storage devices maintaining equal states of charge. The energy storage devices can be batteries with different cell counts, configurations, and energy discharge profiles. In some cases, the power adapters are comprised of DC to DC converters and system controllers that are used to translate each battery's energy discharge profile into a user-determined energy discharge profile that is a predictable function of the battery's state of charge and independent of temperature or other external conditions.

A battery controller for charging and discharging a plurality of batteries is disclosed. The battery controller has a plurality of direct current to direct current (DC to DC) converters connected to each other in series. Each battery of a plurality of batteries is electrically connectable to a respective DC to DC converter. A co-ordinator connected to each of the plurality of DC to DC converters controls charging and discharging of the battery electrically connected to the respective converter. The co-ordinator can also control charging and discharging of any one of the batteries to ensure that the battery retains sufficient electrical capacity, and, to increase the longevity of the respective batteries. Because each battery is electrically connected to a respective DC to DC converter, the energy from one battery can be used to charge another battery in order to monitor battery characteristics including energy capacity of each battery. Each of the DC to DC converters is selected to operate preferably below 30 volts while the total voltage of the entire battery system can be much more than 30 volts depending on the number of DC to DC converters placed in series.

Provided are a porous anode active material, a method of preparing the same, and an anode and a lithium battery employing the same. The porous anode active material includes fine particles of metallic substance capable of forming a lithium alloy; a crystalline carboneous substance; and a porous carboneous material coating and attaching to the fine particles of metallic substance and the crystalline carboneous substance, the porous anode active material having pores exhibiting a bimodal size distribution with two pore diameter peaks as measured by a Barrett-Joyner-Halenda (BJH) pore size distribution from a nitrogen adsorption. The porous anode active material has the pores having a bimodal size distribution, and thus may efficiently remove a stress occurring due to a difference of expansion between a carboneous material and a metallic active material during charging and discharging. Further, the anode electrode and the lithium battery comprising the anode active material have excellent charge/discharge characteristics.

Edge rates for output driver transistors are increased for slower conditions such as caused by supply-voltage, temperature, and process variations. The edge rates are increased by increasing charging and discharging currents to the gates of the driver transistors. Process-sensing transistors have gates tied to power or ground. Current through the process-sensing transistors changes with supply-voltage, temperature, and process variations. The currents through process-sensing transistors are used to generate process-compensated voltages that bias current sources and sinks to adjust process-dependent currents. Process-independent or fixed current sources and sinks use process-independent reference voltages ultimately generated from reference currents that are not sensitive to process variations. The process-dependent-currents are subtracted from the fixed currents to produce the charging and discharging currents.

A method and Apparatus for solar energy storage system uses gas for thermal transport for central tower solar thermal electric power plant to provide high quality, low cost, and continuously electric power generation. The storage contains a number of storage modules that each module can store energy for a given period of time. The thermal energy from central tower charges the modules one by one during the sunny time, while the thermal electric power plant discharge the modules one by one as long as it works. A control and a connection valve system control and connect the charge and discharge modules with the central tower and the power plant according to pre-arranged sequences. Fans at the cool side of the storage system push the circulation gas into the central tower or the thermal storage modules. In the discharge system, the hot gas from storage system is send to the heat exchange system, and to generate steam and to super heat steam for the power plant. In the charge system, the cold gas is pushed into the central receiver thermal exchange unit and to be heated, and the hot gas is then circulated back to storage system to charge up the storage system.

A silicon-based anode comprises an alginate-containing binder. The many carboxy groups of alginate bind to a surface of silicon, creating strong, rigid hydrogen bonds that withstand battery cycling. The alginate-containing binder provides good performance to the anode by (1) improving the capacity of the anode in comparison to other commercially-available binders, (2) improving Columbonic efficiency during charging and discharging cycles, and (3) improving stability during charging and discharging cycles.

Electrode protection in electrochemical cells, and more specifically, electrode protection in both aqueous and non-aqueous electrochemical cells, including rechargeable lithium batteries, are presented. In one embodiment, an electrochemical cell includes an anode comprising lithium and a multi-layered structure positioned between the anode and an electrolyte of the cell. A multi-layered structure can include at least a first single-ion conductive material layer (e.g., a lithiated metal layer), and at least a first polymeric layer positioned between the anode and the single-ion conductive material. The invention also can provide an electrode stabilization layer positioned within the electrode, i.e., between one portion and another portion of an electrode, to control depletion and re-plating of electrode material upon charge and discharge of a battery. Advantageously, electrochemical cells comprising combinations of structures described herein are not only compatible with environments that are typically unsuitable for lithium, but the cells may be also capable of displaying long cycle life, high lithium cycling efficiency, and high energy density.

Positive electrode active materials are described that have a high tap density and high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li_1+xNi_αMn_βCo_γO₂, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the battery.

A battery cell converter (BCC) unit including one or more energy-storing battery cells coupled to one or more DC/DC converters is disclosed. A management unit can monitor and control the charging and discharging of each battery cells; including monitoring of voltages & State-of-Charge of each cell as well as controlling the switching of the DC/DC converters. The combined power and cell switching algorithms optimizes the charging and discharging process of the battery cells. A compound battery cell converter system comprising a series stack of BCCs to achieve high effective converter output voltage is also disclosed. The new proposed Battery Cell Converter architecture will enable improvements in battery pack usage efficiencies, will increase battery pack useable time per charge, will extend battery pack life-time and will lower battery pack manufacturing cost.

The invention discloses a battery managing system (BMS) testing platform comprising a testing platform main control computer, a high-precision cell voltage simulator, a high-precision large-current constant-current source, a high-precision thermotank, a battery managing system to be tested, a whole vehicle controller simulator and the like which are connected by CAN buses. The battery managing system is connected with a cell box air cooling device, a vehicle relay assembly and the like. The battery managing system testing platform can truly simulate the output state of a battery, comprising single cell voltage, total voltage, charging and discharging current, temperature and the like of the battery, can complete various communication and command functions, protection functions, battery heavy current applying process between the battery managing system and the whole vehicle, and the test and the verification on the functions of overhead protection and the like of the battery. The invention can carry out testing evaluation on the data collection precision of the battery managing system, the evaluation precision of the charge state of the battery and the like.

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.

Electronic self-test and/or self-diagnostic systems particularly useful with emergency lighting fixtures, including exit signage having light emitting diodes as light sources and unit emergency fixtures powered with lead-acid batteries, the systems perform testing and diagnostic functions on the circuitry, power supply, charger and lamping of such fixtures either by manual or automatic initiation. Testing functions are provided through use of a programmable microprocessor, the diagnostic circuitry not only monitoring operation of charger/transfer circuitry but also controlling the charger/transfer circuitry to enable alternate strategies for alleviation of a given failure. In emergency mode of a light emitting diode exit sign, a microprocessor-controlled two-stage inverter is employed not only to power the LED light source, but also to efficiently power the microprocessor. Power to the microprocessor is controlled by the microprocessor itself and can therefore be discontinued after appropriate operation until mains power is restored, thereby effectively reducing power consumption to zero. System operation can be flexibly configured through use of a two-wire serial link between modular elements of the system. Incandescent emergency unit fixtures due to high drain rates and output loads require emergency mode operation through use of lead-acid batteries, thereby requiring voltage controlled charging and relay transfer, the self-test and/or self-diagnostic circuitry of the invention used with emergency unit fixtures thus differing in various respects from the circuitry employed for the LED exit signage fixtures and primarily in the need to measure both charge and discharge currents, the circuitry having a larger dynamic range in addition to a capability of measuring both positive and negative currents.

The invention discloses a silicon graphene composite anode material of a lithium ion battery and a preparation method of the silicon graphene composite anode material. The material consists of the following components in percentage by weight: 10 to 99 percent of silicon powder with the particle size of between 20 nanometers and 5 micrometers, 1 to 90 percent of graphene and 0 to 40 percent of amorphous carbon, wherein the graphene forms a three-dimensional conducting network with an internal cavity, and wraps the silicon powder in the internal cavity to form spherical or sphere-like composite particles with the particle size of between 500 nanometers and 15 micrometers. The preparation method of the material comprises the following steps of: uniformly dispersing the silicon powder and graphene oxide in a solvent; and performing spray drying, reducing, and cladding by using the amorphous carbon. Compared with the prior art, the invention has the advantages that: the material has high capacity and high cycle performance and is subjected to a constant-current charge-discharge test at the current density of 200mA/g, the reversible capacity of the material after 30-times circulation is still 1502mA/g, and the capacity retention rate of the material is up to 98 percent; and the preparation method is simple and practicable, high in yield and suitable for mass industrial production.

A non-isolated DC-DC converter that converts a voltage input to an input terminal to output a constant output voltage to a load terminal while switching control mode between a PWM mode and a VFM mode depending on a current output to the load terminal. The DC-DC converter includes an inductor, a switching circuit, and a control circuit. The inductor stores electric energy for supply to the load terminal. The switching circuit switches on and off current flow at a switching frequency to alternately charge and discharge the inductor. The control circuit increases an electric current flowing to the load terminal through the inductor per one operational cycle as the switching frequency decreases during VFM control mode operation.

The invention provides an electronic cigarette casing and an electronic cigarette device, the electronic cigarette casing comprises a case body for accommodating electronic cigarettes, a first power supply configured in the case body and a charging control system for controlling the first power supply to charge the electronic cigarettes, the first power supply comprises a farad capacitor. The electronic cigarette casing using the farad capacitor instead of the traditional batteries to supply electrical power, can achieve the technical effects of safe and reliable charging/discharging, rapid charging, and more charging and discharging times.

Provided is a battery capable of improving cycle characteristics through reducing a structural fracture according to charge and discharge of an anode and a reaction of the with an electrolyte. An anode active material layer includes at least one kind selected from the group consisting of a simple substance and alloys of Si capable of forming an alloy with Li. A cathode and an anode are formed so that the molar ratio Li/Si in the anode at the time of charge is 4.0 or the potential of the anode vs. Li is 0.04 V or more through adjusting, for example, a ratio between a cathode active material and an anode active material. Moreover, the cathode and the anode are formed so that the molar ratio Li/Si in the anode at the time of discharge is 0.4 or more, or the potential of the anode vs. Li is 1.4 V or less.

A high capacity, high charge rate lithium secondary cell includes a high capacity lithium-containing positive electrode in electronic contact with a positive electrode current collector, said current collector in electrical connection with an external circuit, a high capacity negative electrode in electronic contact with a negative electrode current collector, said current collector in electrical connection with an external circuit, a separator positioned between and in ionic contact with the cathode and the anode, and an electrolyte in ionic contact with the positive and negative electrodes, wherein the total area specific impedance for the cell and the relative area specific impedances for the positive and negative electrodes are such that, during charging at greater than or equal to 4C, the negative electrode potential is above the potential of metallic lithium. The current capacity per unit area of the positive and negative electrodes each are at least 3 mA-h/cm², the total area specific impedance for the cell is less than about 20 Ω-cm², and the positive electrode has an area specific impedance r₁ and the negative electrode has an area specific impedance r₂, and wherein the ratio of r₁ to r₂ is at least about 10.