JP2010522533A - Ultrafast battery charger with battery detection - Google Patents

Abstract

  A method for charging a rechargeable battery having at least one rechargeable electrochemical cell is disclosed. The method determines the corresponding battery capacity based on the identification information received from the rechargeable battery and determines so that the battery achieves a predetermined charge that is reached within a charging period of less than 15 minutes. Determining a charging current level to be applied to the rechargeable battery based on the corresponding corresponding battery capacity and applying a charging current having a substantially substantially determined current level to the battery.

Description

  Lithium ion rechargeable batteries are charged by a constant current source and subsequently charged by a constant voltage (CC / CV) with a crossover from constant voltage to constant current at about 4.2V (ie, the charging operation is When the battery voltage reaches about 4.2 V, the constant current mode is switched to the constant voltage mode). The source of such charging characteristics is controlled by an electronic feedback mechanism.

  Careful and precise control of the charging mechanism of the charging device is required to charge the rechargeable battery within a given period of time and to avoid damage to the battery due to improper charging current application. Accurate measurement of battery voltage and / or current is required to facilitate accurate control of the charging current. In addition, since batteries have different capacities and require different levels of charging current, battery capacities are required to complete charging operations within a given period and avoid damage to rechargeable batteries and / or chargers. Accurate information about is needed.

  An ultra-fast charger is disclosed that can charge different rechargeable batteries and / or different charge capacities within a given charge period (eg, charge 90% capacity in 5 minutes).

  In one aspect, a method for charging a rechargeable battery having at least one rechargeable electrochemical cell is disclosed. The method determines the corresponding battery capacity based on the identification information received from the rechargeable battery and determines so that the battery achieves a predetermined charge that is reached within a charging period of less than 15 minutes. Determining a charging current level to be applied to the rechargeable battery based on the corresponding corresponding battery capacity and applying a charging current having a substantially substantially determined current level to the battery.

  Embodiments may include one or more of the following.

  The step of determining the corresponding battery capacity is a step of applying a test current to the identification resistor of the rechargeable battery, wherein the identification resistor represents the corresponding battery capacity, and the identification voltage drop at the identification resistor is Measuring.

  Determining the charging current can include reading a value corresponding to the charging current level from a lookup table so that it can be applied to the rechargeable battery based on the identification voltage drop.

  The step of determining the charging current includes calculating a resistance value based on the measured identification voltage drop and the test current, and determining a charging current level to be applied to the rechargeable battery based on the calculated resistance value. Selecting from a look-up table.

  The method can further include determining the temperature of the rechargeable battery and adjusting the charging current based on the determined temperature.

  The method may further include terminating the charging current after a charging time substantially equal to the charging period has elapsed.

  The predetermined charge of the battery can be at least 90% of the battery capacity of the battery and the charge period can be about 5 minutes.

  Applying the charging current includes applying a charging current to the rechargeable battery via a first set of terminals of the charger device, the first set of terminals being configured to apply the current. . The method can further include monitoring a voltage at a terminal of the rechargeable battery via a second set of detection terminals of the charger device, wherein the second set of terminals is configured to measure the voltage. Has been.

  In another aspect, a method for charging a rechargeable battery having at least one rechargeable electrochemical cell is disclosed. The method includes applying a charging current to the rechargeable battery via a first set of charging terminals of the charger device, wherein the first set of terminals is configured to apply the current; Monitoring the voltage at the terminal of the rechargeable battery via the second set of detection terminals of the charger device, wherein the second set of terminals is configured to measure the voltage; including.

  As with the first method aspect described above, other method embodiments may include any feature corresponding to any of the features described above with respect to the first method aspect.

  In a further aspect, a charger device configured to charge a rechargeable battery having at least one rechargeable electrochemical cell is disclosed, the rechargeable battery having a corresponding battery capacity associated with the rechargeable battery. A battery identification mechanism configured to communicate identification information representing is included. The device is a charging compartment configured to receive a rechargeable battery and communicates with a charging terminal configured to be coupled to each battery terminal of the rechargeable battery and a battery identification mechanism of the rechargeable battery. And a charging section including a battery identification reading mechanism for receiving identification information. The device is configured to determine a corresponding battery capacity based on the communicated identification information of the rechargeable battery so that the battery achieves a predetermined charge that is reached within a charging period of 15 minutes or less. Based on the determined corresponding battery capacity, the charging current level to be applied to the rechargeable battery is determined, and a charging current having a substantially substantially determined current level is applied to the rechargeable battery. And a controller configured as described above.

  As with the method aspects, device embodiments can include any feature corresponding to any of the features described above as well as the following features of the method.

  The device may include a rechargeable battery.

  However, in another aspect, a charger device is disclosed that is configured to charge a rechargeable battery having at least one rechargeable electrochemical cell. The device includes a charging compartment configured to receive a rechargeable battery, the charging compartment including a first set of charging terminals configured to apply current to each battery terminal of the rechargeable battery, and the rechargeable battery. And a second set of detection terminals configured to measure the voltage of the battery. The device applies a charging current to the rechargeable battery via the first set of charging terminals of the charger device and monitors the voltage between the terminals of the rechargeable cell via the second set of detection terminals. It further includes a configured controller.

  Device embodiments may include any feature corresponding to any of the above-described features of the method and device.

  In a further aspect, a charging device is disclosed. The apparatus includes a rechargeable battery having at least one rechargeable electrochemical cell, wherein the rechargeable battery is configured to communicate identification information associated with the rechargeable battery and representing a corresponding battery capacity. Have The apparatus further includes a charging zone configured to receive a rechargeable battery, the charging zone being configured to be coupled to each terminal of the rechargeable battery, and a battery identification mechanism for the rechargeable battery. And a battery identification reading mechanism for receiving identification information. The device is configured to determine a corresponding battery capacity based on the identification information of the rechargeable battery, and determined to achieve a predetermined charge that the battery reaches within a charging period of less than 15 minutes. Based on the corresponding battery capacity, configured to determine a charging current level to be applied to the rechargeable battery, and configured to apply a charging current having a substantially substantially determined current level to the battery A controller is further included.

  Apparatus embodiments may include any feature corresponding to any of the above-described features of the present methods and devices.

  In a further aspect, a docking station system is disclosed. The docking system includes a charging compartment configured to receive a battery-operable device having at least one rechargeable battery, the charging compartment being connected to each connection of the battery-operable device. And an identification reading mechanism configured to communicate with an identification mechanism of a battery operable device, and an identification information representative of a battery capacity associated with at least one rechargeable battery. An identification mechanism. The docking station system is configured to determine a corresponding battery capacity based on the communicated identification information to achieve a predetermined charge in which at least one rechargeable battery is reached within a charging period of 15 minutes or less. As such, it further includes a controller configured to determine a charge current level to be applied to the at least one rechargeable battery of the battery operable device based on the determined corresponding battery capacity.

  Embodiments of the docking station system may include any feature corresponding to any of the above-described features of the method, device, apparatus, as well as the following features.

  The system may further include a battery operable device. Examples of a battery operable device include one of a mobile phone, a personal digital assistant (PDA), a digital camera, an audio device, and / or a multimedia device.

  The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

1 is a block diagram of an exemplary embodiment of a charging device including a charger and a battery. FIG. 2 is a block diagram of an exemplary embodiment of the charger shown in FIG. The circuit diagram of the typical circuit of the charger of FIG. 1 is a representative embodiment of an AC / DC switching device. 6 is a flowchart of an exemplary embodiment of a charging procedure. 1 is an exemplary embodiment of a docking station that accepts a battery-operable device.

  FIG. 1 shows a charger 10 configured to charge a battery 12 having at least one electrochemical cell. The battery 12 may be a secondary cell (or battery) or a primary cell. A primary electrochemical cell is intended to be discharged only once, for example until it is completely consumed, and then discarded. Primary batteries are not intended for recharging. Primary batteries are described, for example, in David Linden's “Handbook of Batteries” (McGraw-Hill, 1995, 2nd edition). The secondary electrochemical cell can be recharged many times, eg, more than 50 times, more than 100 times or more. In some cases, secondary cells may include relatively robust separators, such as separators having multiple layers and / or separators that are relatively thick. The secondary cell can also be designed to accommodate changes such as expansion that can occur in the cell. Secondary cells are, for example, Falk & Salkind's “Alkaline Storage Batteries” (John Wiley & Sons, Inc., 1969), U.S. Pat. No. 345,124 and French Patent 164,681, all of which are incorporated herein by reference. In the embodiments described herein, the battery 12 is a secondary or rechargeable battery.

  In some embodiments, the rechargeable battery 12 comprises a graphite-like anode material or a lithium titanate anode material, and a lithiated phosphorous acid adapted to allow fast charging of the rechargeable battery based on such materials. A lithium ion cell having an iron oxide cathode material is included. The charger 10 may be further configured to charge different types of batteries, including, for example, cylindrical batteries, prismatic batteries, button cell batteries, and the like.

  In the battery 12, charging terminals 14a and 14b are electrically and mechanically connected to terminals 18a and 18b of the battery 12, respectively, and detection terminals 16a and 16b are electrically and mechanically connected to detection terminals 20a and 20 of the battery 12, respectively. Receivable within the charging compartment of charger 10 to be coupled. In some embodiments, the terminals 18a, 18b, 20a and 20 are adapted to be connected in a manner that engages each terminal 14a, 14b, 16a and 16b located within the charging compartment of the charger 10. It is a pin. The charger 10 determines the appropriate charging current to be applied to the battery 12 and applies that charging current through the terminals 14 a and 14 b to the battery 12 via the terminals 18 and 18 of the battery 12. A voltage sensor electrically connected to terminals 16a and 16b measures the voltage at terminals 20 and 20b (corresponding to the voltage at terminals 18a and 18b of battery 12). Based on the measured voltage, the charger 10 makes the necessary adjustments to the charging voltage and / or current applied to the battery 12 so that the charger 10 can have a specific charging profile for the battery 12 (eg, less than 15 minutes). The charging operation of the battery 12 can be completed. The charger 10 may also include one or more current sensors connected to the charging terminals 14a and 14b of the charger 10 in some embodiments. Although FIG. 1 shows a single battery 12, the charger 10 may be adapted to accept and charge additional rechargeable batteries. Furthermore, the charger 10 may be configured to accept and charge different battery types, including cylindrical batteries, prismatic batteries, coin or button batteries, and the like.

  The charger 10 is configured to charge batteries having different capacities. The charger determines the capacity of the rechargeable battery 12 connected to the charger 10. Based on the determined battery capacity, the charger 10 determines the current to be applied to the rechargeable battery 12 such that a predetermined charge (eg, 90% capacity) of the battery 12 is reached, for example, within about 5 minutes. Determine the level. In order to achieve this charging performance, a charging current corresponding to about 10 to 15 C is required (1 C is a charging rate corresponding to a charging current at which a specific rechargeable battery is charged in one hour. And a charging rate of 12 C corresponds to a current level at which a specific battery is charged in 5 minutes (ie, 1/12 of an hour)).

  Since the charger is configured to charge batteries with different capacities, the capacity of the battery 12 can be one of several possible capacities, and different levels of charging current can be Applied according to capacitance. Typically, battery capacity ranges from 50 mAh to 3 Ah, where “Ah” is a unit of battery capacity ampere-hours. Other capacities can be accommodated. Thus, for example, to charge a 500 mAh capacity battery to over 90% of its maximum capacity at a charging rate of 12C (ie in about 5 minutes), a charging current of about 6A is required (ie 6A × 1/12). Time = 500 mAh). On the other hand, a charging current of about 8.5 A is required to charge a 700 mAh battery with a charging rate of 12 C.

  The charger 10 (a) ensures that the battery 12 is charged to its predetermined charge level within a predetermined period of time (b) that the battery voltage does not exceed a predetermined upper limit voltage. To ensure and / or (c) the rate of voltage increase (i.e. the rate at which the voltage at the charging terminal of the battery 12 increases as the charging operation proceeds) follows a prescribed charging profile (e.g. Is configured to control the charging process, such as controlling the voltage and / or current applied to the battery 12.

  Control of the charging process requires monitoring of the voltage at the battery 12 terminals. Accordingly, accurate measurements of the voltage at the terminals of the battery 12 are required to perform the necessary adjustments to the voltage and / or current applied to the battery 12. However, since the charging terminal of the charger has a non-negligible resistance, in a situation where voltage detection is coupled to the charging terminal of the charger, the measured voltage drop is caused by the resistance of the charging terminal of the charger. It will include a voltage drop at 10 charging terminals. As a result, a charger that includes voltage detection that is directly connected to the charging terminal of the charger can introduce some measurement error.

  Therefore, to reduce the effects of voltage measurement errors, the charger 10 applies a charging current using one set of terminals (ie, terminals 14a and 14b) and another dedicated set of terminals (ie, terminal 16a). And 16b) to measure the battery voltage. The two charging terminals 14 a and 14 b of the charger 10 are adapted to be coupled to the corresponding charging terminals 18 a and 18 b of the battery 12, and the two other detection terminals 16 a and 16 b of the charger 10 are compatible with the battery 12. Adapted to be electrically connected to dedicated detection terminals 20a and 20b. Such a 4-terminal configuration, such as that shown in FIG. 1, may be referred to as a Kelvin configuration or Kelvin connection. The detection terminals 16a and 16b of the charger 10 are electrically isolated from the charging terminals 14a and 14b of the charger 10, thus reducing voltage measurement errors that may otherwise occur when the two sets of terminals are coupled together. To do. By using a separate charging terminal and a separate detection terminal, the charging process can be accurately controlled. Terminal 18a is in electrical communication with detection terminal 20a, similarly terminal 18b is in electrical communication with detection terminal 20b, and thus voltage feedback corresponds to the voltage at the charging terminal of battery 12. .

  In some embodiments, additional terminals or pins within the charging compartment of the charger may be used to allow determination of battery capacity and / or other relevant information regarding the battery 12. Specifically, the charger 10 provides the charger 10 with identification information representing the battery capacity, type, model and / or other data closely related to the charging operation performed on the rechargeable battery 12. A battery identification reading mechanism including an ID detection terminal 22 configured to be mechanically and electrically coupled to the identification mechanism of the battery 12 configured as described above. The charger 10 is configured to communicate with an identification mechanism and receive identification information. Based on the identification information received from the battery 12, the charger 10 determines a charging current to be applied to the battery 12.

  One such example of a battery identification mechanism is a battery ID resistor 26 having a resistance value that represents the model of the corresponding battery, type and / or battery 12. The ID resistor 26 may be disposed inside the casing of the battery 12 or may be disposed outside the battery 12. In the example shown in FIG. 1, the ID resistor 26 is electrically coupled to a dedicated battery ID terminal 24 that is adapted to mechanically and electrically couple to the terminal 22 of the charger 10.

The ID resistor 26 is electrically connected to the power terminal 18b and the detection terminal 20b of the battery 10. Thus, when a current or voltage is applied from the terminal 22 of the charger 10 to the ID terminal 24 of the battery 12, a closed electrical path is formed between the terminals 18b and 24 of the battery 12 and the current through the ID resistor 26. Can flow. In order to obtain battery capacity and / or identification, a predetermined test current, I _test, is applied by the charger 10 to the ID resistor 26 via the ID terminal 24. The voltage drop V _R1 across the ID resistor 26 is measured using the voltage sensor of the charger 10 coupled to terminal 22. The voltage drop measured at the ID resistor 26 is communicated to the charger 10, which calculates the resistance of the ID resistor 26 with R1 = V _R1 / I _test using the measured voltage.

The calculated resistor R1 corresponding to the ID resistor 26 is used to access a look-up table that holds each of the data for different resistance values. Such data may include each battery capacity associated with a resistance value, an acceptable charging current value applied to the battery, and / or other information closely related to the charging process. Alternatively, the measured voltage V _R1 may be used to access the lookup table.

  In some embodiments, the ID resistor 26 is a thermistor whose resistance changes with changing temperature. Such an ID thermistor can thus be used both for identifying the type of battery to be charged and for monitoring the temperature of the battery. The charger 10 determines the temperature of the battery based on the change in resistance of the thermistor. For example, the determination of the battery temperature was calculated by measuring the voltage at the thermistor, resulting from applying a certain level of current, as well as based on the measured voltage or the measured voltage. This is done by matching the resistance and applied current to a look-up table relating the measured value to the corresponding temperature for a particular battery capacity or type. When the battery temperature reaches a level that is determined to be unsafe, the charger 10 reduces the battery temperature based on the determined temperature, either by reducing the charging current or terminating. In some embodiments, the charger 10 may not implement a temperature control mechanism and / or a temperature monitoring mechanism; therefore, in such an embodiment, the battery and / or charger temperature determination tasks, and those The reaction to is not performed.

  Other types of battery identification mechanisms may be employed. A suitable battery identification mechanism may include a radio frequency identification (RFID) mechanism, which reacts to an activation signal (eg, a radio signal) to cause the RFID device to have a battery capacity, type, battery charge status / health status. And so on, to communicate to the charger 10. Other suitable identification mechanisms include identifying the battery (e.g., Smart Battery SMBus standard) and identifying data representing the capacity and / or type of battery to be communicated to the charger 10 via serial data communication. A mechanism for executing serial communication technology provided through an interface is mentioned. In some embodiments, the determination of the charging current may be performed by measuring at least one of the battery's electrical characteristics that represent the capacity and / or type of the battery (eg, the battery's DC charging resistance). A detailed description of a representative charger device that adaptively determines the charging current based on the measured characteristics of the battery is a patent application filed concurrently with the name “Adaptive Charger Device and The method is provided in “Adaptive Charger Device and Method”, the entire contents of which are incorporated herein by reference.

  As further shown in FIG. 1, the charger 10 includes a user interface 30. The user interface 30 includes an output device, such as an LED, that provides status information to the user regarding the charger 10 and / or the battery 12 connected thereto. The user interface 30 is lit when the charger is activated and connected to an external power source (such as an AC power source connected to the charger 10 via the AC power port 28), for example, a blue LED 32 "Charge Includes “Charger On”. The user interface includes, for example, a red LED 34 that is activated when a battery that cannot be accommodated by the charger 10 is inserted into the charging compartment, creating a steady red illumination. Such batteries include, for example, disposable non-rechargeable batteries or rechargeable batteries in which the ID resistor 26 has a value that represents a capacity or battery type that the charger 10 is not configured to accommodate. The red LED 34 may be activated to create a red light that flashes when a defective battery is inserted into the charging compartment. For example, a battery with an initial voltage level of, for example, less than 2V may be damaged, so that the charger 10 cannot begin a charging operation until a suspected damaged battery is removed. The red LED may be lit upon detecting a fault condition that may adversely affect the operation of the charger and / or cause the charger or battery to fail. Such fault conditions include detection of abnormal voltage levels at the terminals of the battery, overheating conditions of the battery and / or charger (eg, when a temperature exceeding 60 ° C. is detected), and the like. A detailed description of a typical procedure for detecting and reacting to fault conditions occurring in the process of charging a battery is a patent application filed concurrently with the name “Fast Battery Charger Device. and the contents of which are incorporated herein by reference in their entirety.

  The user interface 30 also includes a yellow LED 36 that lights when the charger is charging the battery 12 with a current of, for example, 6A. Such a charging current may indicate that the battery installed in the charging compartment of the charger 10 has a capacity of 500 mAh and completes the charging operation in about 5 minutes with a charging current of 6A. The user interface 30 also includes a green LED 38 that is lit when the charger is charging the battery 12 with a current of, for example, 8.5A. Such a charging current may indicate that the battery installed in the charging compartment of the charger 10 has a capacity of 700 mAh and that the charging operation is also completed in about 5 minutes at a charging current of 8.5 A. The user interface 30 can include additional LEDs that can each correspond to different states (eg, different fault conditions), different battery capacities, and the like. Further, the colors and / or lighting schemes described herein may be altered so that different colors can accommodate different battery capacities or different conditions.

  User interface 30 may include a display device configured to provide output information to a user. For example, in situations where a suspected faulty battery or an illegal battery is installed in the charging compartment, the user interface will generate and display a “bad battery” or “illegal battery” message.

  The user interface 30 may further include a user input area (not shown) that may include switches, buttons, and / or knobs that allow the user to indicate other types of parameters related to, for example, a charging period and / or charging process. Good. Thus, if the user wants to replace the battery at a rate other than the rate at which the battery will be charged at least 90% within about 5 minutes, the user must do so via the user input area of the interface 30. Can do. Charger based on battery identification (determined by specifying battery type and / or capacity via user input area, via identification mechanism such as ID resistor, or via other battery determination scheme) Can access a look-up table showing preferred charging currents based on charging duration and battery identification and / or capacity. In some embodiments, a suitable charging current may be determined using computational techniques. The user input area of the user interface 30 may also include input elements (eg, switches) for enabling or disabling the charger 10.

  In some embodiments, the charger 10 is adapted to charge a battery installed in a socket or device (eg, a mobile phone where a rechargeable battery is left in the mobile phone during a charging operation). Also good. In such an embodiment, the battery fitted in the device is electrically coupled to, for example, a 5-pin terminal disposed on the device case. Alternatively, such a battery may be coupled to a female connector to avoid a short circuit of the battery. The charger includes a docking station that is powered by an AC or CLA (12V, automotive cigarette lighter adapter) and built to accept a device with an embedded rechargeable battery under these circumstances. be able to. The device is installed in the docking station in an engaged configuration. The docking station starts the ID confirmation and applies a corresponding charging current determined based on the battery capacity (determined by the ID confirmation) to charge the device battery in about 5 minutes. Referring to FIG. 6, a battery-operable device such as a representative docking station 100 and a personal digital assistant (PDA) 102 configured to be received in a configuration that engages the docking station 100 is shown. ing. The docking station includes connections 104 that are each coupled to a connection (also not shown) located on a battery-operable device (PDA 102 in this case). In some embodiments, the battery-operable device includes one of a mobile phone, a personal digital assistant (PDA), a digital camera, an audio device, and a multimedia device. In some embodiments, the charger 10 may increase the charging current to prevent arcing of the charger connections.

  FIG. 2 illustrates details of an exemplary embodiment of charger 10. The charger 10 includes a power conversion module 40 that includes an AC-DC converter 42 that is electrically coupled to an AC power source external to the charger, such as a source that supplies power at a rating of 85 V to 265 V and 50 Hz to 60 Hz. Including, converting the AC power into a low DC voltage (e.g. 5-24V), for example sending this low DC voltage to e.g. a DC-DC converter 44 to provide a level suitable for charging a rechargeable battery (For example, in the above lithium ion cell, the DC voltage is a DC voltage at a level between about 3.7-4.2 V. Other types of cells may have different voltage levels.) AC- The DC converter 42 is implemented as a separate AC / DC switching device configured to accept input power at the first AC voltage and convert it to a lower DC constant voltage. An exemplary embodiment of the AC / DC switching device 70 is shown in FIG. The AC-DC converter 42 includes galvanic isolation between the AC input line and the DC output to prevent input AC current from reaching the DC output area of the AC-DC converter 42.

  The AC-DC converter 42 may also include a feedback mechanism (not shown) for controlling the DC output voltage of the converter 42 such that a substantially constant voltage level is provided at the output of the converter.

  In some embodiments, the DC-DC converter 44 is incorporated into the power conversion module 40 to provide an external DC power source, such as a vehicle DC power supply, suitable for charging a rechargeable battery. Convert to For example, a DC power supply for an automobile supplies approximately 11.5-14.3 V DC power, and the DC-DC converter 44 converts the power level to a suitable power level. Other power conversion configurations may be used.

  In some embodiments, the power conversion module 40 is disposed within the housing of the charger 10. Alternatively, the power conversion module 40 may be disposed in a separate housing that is adapted to be electrically connected to the charger 10.

  The charger 10 includes a controller 50 that determines a charging current to be applied to the battery 12 and applies the determined charging current to the battery 12. The controller 50 also terminates the charging current after a specified or predetermined period has elapsed. The controller 50 can also be configured to terminate the charging current when a predetermined battery voltage or charge has been reached. As described herein, the determination of the charging current is installed in the charging compartment of the charger 10 using, for example, an identification mechanism that communicates data representing the capacity and / or type of the battery 12. May be performed by identifying the capacity and / or type of the battery (s).

  The controller 50 includes a processor device 52 configured to control the charging operation performed on the battery 12. The processor device 52 may be any type of computing and / or processing device, such as a PIC18F1320 microcontroller from Microchip Technology Inc. The processor device 52 used to implement the controller 50 includes a volatile memory and / or a non-volatile memory element configured to store software including computer instructions to enable general operation of the processor-based device. And a battery 12 connected to the charger including, for example, a charging operation that achieves a charging capacity of at least 90% in about 5 minutes, and an operation to identify or determine the capacity and / or type of the battery 12 Includes an execution program for executing the charging operation.

  The processor 52 includes an analog-to-digital (A / D) converter 54 having a plurality of analog and digital input and output lines. The A / D converter 54 receives signals from sensors connected to the battery 12, such as voltage sensors connected to the detection terminals 16a and 16b of the charger 10, to facilitate adjustment and control of the charging operation. Configured. In some embodiments, the controller 50 may include a digital signal processor (DSP) to perform some or all of the processing functions of the control device.

  The controller 50 receives the digital signals generated by the digital-to-analog (D / A) converter device 56 and / or the processor device 52 and controls the switching circuit such as the back converter 60 of the rechargeable battery 10 accordingly. A pulse width modulator (PMW) 58 that generates a signal is also included.

  In some embodiments, the charger 10 automatically battery and / or charge so that the battery terminals (charging and / or sensing) are in electrical communication with the respective terminals of the charger 10. An automatic attachment / detachment mechanism (not shown) may be included that moves the compartment from a first entry position on the charger 10 to a second position. Disclosed in the patent application title “Battery Charger with Mechanism to Automatically Load and Unload Batteries,” filed at the same time and incorporated herein by reference in its entirety. As is done, at the end of the charging operation, the charger 10 causes the automatic attachment / removal mechanism to remove the battery and move the battery from its second position to its entry position.

  FIG. 3 stores energy when two, for example, bipolar junction transistors (BJT) 62 and 64, and the power conversion module 40 are in electrical communication with the buck converter 60. 1 illustrates a buck converter 60 that includes an inductor 66 that discharges its energy as a current during electrical isolation from the current. The buck converter 60 shown in FIG. 3 also includes a capacitor 68 that is also used as an energy storage element. Inductor 66 and capacitor 68 also function as an output filter to reduce switching current and voltage ripple at the output of buck converter 60.

  The power transmitted from the power conversion module 40 to the battery 12 is adjusted by controlling the voltage level applied to the bases of the transistors 62 and 64. In order to apply the power from the power conversion module 40 to the terminals 18a and 18b of the battery 12, an operating electrical signal from the terminal 50d (marked SW1) of the controller 50 is applied to the base of the transistor 62 for power conversion. A current flows from the module 40 to the transistor 62 and the battery 12.

  When the operating signal applied to the base of transistor 62 is turned off, current flow from power conversion module 40 stops and inductor 66 and / or capacitor 68 supplies current from the energy stored therein. During the off period of transistor 62, a second operating signal is applied to the base of transistor 64 by terminal 50e of controller 50 (marked SW2), and current flow through battery 12 (turning on of transistor 62). (Using energy stored in inductor 66 and / or capacitor 68 during the period). In some embodiments, a rectifier diode is utilized in place of transistor 64, which provides functionality similar to transistor 64.

  While the controller or feedback loop measures the output current and voltage, the on period of the transistor, i.e. the duty cycle, initially increases from 0% duty cycle. When the determined charging current to be applied to the battery 12 is reached, the feedback control loop is closed loop linear feedback scheme, eg, proportional-integral-differential, ie PID. A mechanism is used to manage the transistor duty cycle. When the charger voltage output or battery terminal voltage reaches the crossover voltage, a similar control mechanism may be used to control the duty cycle of the transistor.

  Thus, the current supplied by the power conversion module 40 during the on period of the transistor 62 and the current supplied by the inductor 66 and / or capacitor 68 during the off period of the transistor 62 is substantially equal to the required charging current. The effective current should be equal to each other.

  In some embodiments, the controller 50 may measure the current flowing through the battery 12, as measured by a current sensor that communicates a value measured, for example, via the terminal 50c of the controller 50 (marked ISENSE). Are measured periodically (for example, every 0.1 second). Based on this received and measured current, controller 50 adjusts the duty cycle to adjust the current flowing through battery 12 such that the current converges to a value substantially equal to the charge current level. . Thus, the buck converter 60 is configured to operate with an adjustable duty cycle so that an adjustable current level is supplied to the battery 12.

  In addition to the voltage sensor and / or current sensor, the charger 10 may include other sensors configured to measure any other characteristic of the battery 12 and / or the charger 10. For example, the charger 10 may include a circuit board on which a temperature sensor and / or controller 50 coupled to the battery 12 is disposed. As described, in situations where the battery 12 includes a thermistor to function as the ID resistor 26, the thermistor is used to measure the temperature of the battery and determine whether the battery may be overheated. The The charger 10 also includes a temperature sensor (eg, a thermistor-based sensor or thermometer) to measure the temperature of the circuit board on which the controller 50 module is disposed and the board is overheated (eg, If the temperature of the substrate exceeds 60 ° C., the controller 50 may be able to take corrective or preventive measures. Corrective and / or preventive actions to invalidate the dangerous operating situation include terminating the charging operation or reducing the charging current to reduce the temperature of the battery 12 and / or the charger 10.

  In some embodiments, an analog logic processing element (e.g., a dedicated charge control device that may include a threshold comparator) to determine the voltage level and current level measured by the voltage and / or current sensor (see FIG. (Not shown) is used to process the received and measured signal. The charger 10 further includes signal conditioning blocks such as filters 51 and 53 to perform signal filtering and processing on the analog and / or digital input signals, and can be caused by external factors such as circuit level noise. Accurate measurement (for example, inaccurate measurement of voltage, temperature, etc.) may be prevented.

  When the upper limit is reached, the controller 50 is further configured to maintain the voltage at the terminals of the battery 12 near a substantially constant predetermined upper limit voltage (also referred to as a crossover voltage). While the battery 12 is being charged with a current substantially equal to the charging current, the voltage at the battery terminal increases. To ensure that the voltage at the battery terminals does not exceed a predetermined upper voltage limit (so that the battery does not overheat or otherwise adversely affect battery operation or expected life) ), Using a voltage sensor, the voltage at the terminal of the battery 12 is measured periodically (eg every 0.1 seconds) to determine when a predetermined upper limit voltage has been reached. The measured voltage is communicated to the controller 50 via terminal 50b (marked VSENSE). When the voltage at the terminal of the battery 12 reaches a predetermined upper limit voltage, the current / voltage control circuit is controlled to become a substantially constant voltage at the terminal of the battery 12.

  In some embodiments, the controller 50 is configured to monitor the rate of voltage rise by periodically measuring the voltage at the terminals of the battery 12 and within a specified voltage rise period with a predetermined upper limit voltage. So that the charging current applied to the battery 12 is adjusted. The charge current level is adjusted based on the measured voltage increase rate so that the predetermined upper limit voltage is reached within the specified voltage increase period, and the charge current is increased or decreased. The adjustment of the charging current level may be performed according to a predictor corrector technique using, for example, a Kalman filter. Other methods of determining adjustments to the current to achieve the upper voltage limit may be used.

  FIG. 5 illustrates an exemplary charging procedure 80 for charging the rechargeable battery 12 inserted into the charging compartment of the charger 10. When installed in the charging compartment, the charging terminals 14 a and 14 of the charger 10 are electrically connected to the charging terminals 18 a and 18 b of the battery 12, and the detection terminals 16 a and 16 b of the charger 10 are charged to the battery 12. It is electrically connected to terminals 20a and 20b. By measuring the voltage and / or current of the battery through the dedicated detection terminal of the charger 10 rather than through the charging terminal of the charger 10, as described herein, Occurrence is reduced, thus providing more precise control of the charging procedure performed by the charger 10.

If desired, the charger 10 determines whether any fault conditions exist before the start of the charging operation. Thus, the charger 10 measures the temperature and voltage of the battery 12 (82). The charger 10 determines whether the initially measured temperature T ₀ and voltage V ₀ are within a predetermined range (eg, V ₀ is 2 to 3.8 V, temperature T ₀ is less than 60 ° C.). (84). Therefore, in situations where the measured temperature and / or voltage is determined not to be within a predetermined tolerance range, the charging operation under the current situation is made unsafe, the charger does not start the charging operation and the procedure 80 ends.

If the measured temperature T ₀ and voltage V ₀ are within their respective predetermined limits, the charger 10 applies a predetermined value of the test current I _test to the ID resistor 26 of the battery 12 (86). The resulting voltage drop V _R1 at ID resistor 26 is measured using a voltage sensor coupled to terminal 22 of charger 10.

Measuring the voltage _VR1 , the resistance of the ID resistor 26 is calculated as follows (88).

  The calculated resistance represents the battery 12 connected to the charger 10 and thus represents the capacity of the battery. Accordingly, the calculated value of resistance is used to determine the charging current applied to battery 12 (90). The processor 50 accesses a look-up table that shows the preferred charging current corresponding to the capacity associated with the calculated resistance value. In situations where the determined capacity is associated with multiple charging current entries, the user's desired charging period (eg, specified using the input area of the user interface 30) is used to identify the ID resistor. The appropriate entry associated with the battery capacity and / or type identified from the calculated resistance of the 26 battery characteristics may be selected. In general, in embodiments where a charging period of 5 minutes is used, the charging current value that charges the battery 12 having the determined battery capacity in 5 minutes is read from the lookup table. For example, if it is determined based on the calculated resistance of the ID resistor 26 that the connected battery has a capacity of 500 mAh, a value representing a charging current of 6 A is read from the lookup table.

  The charging current to be applied to the battery 12 is determined, and a current / voltage control circuit such as the buck converter 60 shown in FIG. 3 is controlled (92) so that the voltage from the power conversion module 40 is rechargeable battery. 12 is supplied with a constant current. As explained, the charging current level value calculated at 90 is processed to generate a duty cycle signal, generating a current substantially equal to the charging current to be applied to the battery 12. The controller output signal is applied to, for example, the transistor 62 of the buck converter 60, and the voltage from the power conversion module 40 is applied to the battery 12. During a specific duty cycle off time, the power conversion module 40 is disconnected from the battery 12 and the energy stored in the inductor 66 and / or capacitor 68 is discharged to the battery as current. The combined current applied from power conversion module 40 and the current discharged from inductor 66 and / or capacitor 68 is an effective current substantially equal to the determined charging current.

  While the battery 12 is being charged with a substantially constant current, the voltage at the battery terminal increases. To ensure that the voltage at the battery terminal does not exceed a predetermined upper limit voltage, the voltage at the battery 12 terminal is measured periodically (eg, every 0.1 second) (94), It is determined when a predetermined upper limit voltage has been reached. When the voltage at the terminal of the battery 12 reaches a predetermined upper limit voltage, the current / voltage control circuit (e.g., via electrical actuation of the transistors 62 and 64) is configured so that a constant voltage level is created at the terminal of the battery 12. Be controlled.

  If desired, the rate of voltage rise is measured periodically (96) to reach a predetermined upper limit voltage within a specified voltage rise period. Based on the measured voltage rise rate, an operation applied to the current / voltage control circuit to increase or decrease the charging current so that a predetermined upper limit voltage is reached within a specified voltage rise period. The charge current level is adjusted (with corresponding adjustment of the signal).

  After a time substantially equal to the charging period has elapsed, as determined (98), the charging current applied to the battery 12 is supplied from the power conversion module 40 (eg, the electrical operation of the transistor 62 is stopped). Exit by terminating the power being played. The charging procedure ends when a certain period of time has expired after a predetermined upper limit voltage of battery 12 has been reached, or after a specified charge level of battery 12 has been reached.

Other Embodiments A number of embodiments of the invention have been described. However, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims (10)

A method of charging a rechargeable battery having at least one rechargeable electrochemical cell, the method comprising:
Determining a corresponding battery capacity based on the identification information received from the rechargeable battery;
Determining a charge current level to be applied to the rechargeable battery based on the determined corresponding battery capacity so that the battery achieves a predetermined charge reached within a charging period of 15 minutes or less; ,
Applying a charging current having substantially the determined current level to the battery;
Including a method. Determining the corresponding battery capacity,
Applying a test current to an identification resistor of the rechargeable battery, wherein the identification resistor represents the corresponding battery capacity;
Measuring an identification voltage drop at the identification resistor;
The method of claim 1 comprising:   The method of claim 2, wherein determining the charging current includes reading a value corresponding to the charging current level from a lookup table so that the charging current can be applied to the rechargeable battery based on the identification voltage drop. Method. Determining the charging current comprises:
Calculating a resistance value based on the measured identification voltage drop and the test current;
Selecting from the look-up table the charging current level to be applied to the rechargeable battery based on the calculated resistance value;
The method of claim 2 comprising: Determining the temperature of the rechargeable battery;
Adjusting the charging current based on the determined temperature;
The method of claim 2 further comprising:   The method of claim 1, further comprising terminating the charging current after a charging time substantially equal to the charging period has elapsed.   The method of claim 1, wherein the predetermined charge of the battery is at least 90% of the battery capacity of the battery and the charge period is about 5 minutes.   The step of applying the charging current includes the step of applying a charging current to the rechargeable battery via a first set of terminals of a charger device, wherein the first set of terminals is configured to apply a current. The method of claim 1, wherein: A method of charging a rechargeable battery having at least one rechargeable electrochemical cell, the method comprising:
Applying a charging current to the rechargeable battery via a first set of charging terminals of a charger device, wherein the first set of terminals is configured to apply a current; and
Monitoring a voltage at a terminal of the rechargeable battery via a second set of detection terminals of the charger device, wherein the second set of terminals is configured to measure the voltage. When,
Including methods. A charger device configured to charge a rechargeable battery having at least one rechargeable electrochemical cell, the rechargeable battery being associated with the rechargeable battery and identifying information representing a corresponding battery capacity A battery identification mechanism configured to communicate, the device comprising:
A charging compartment configured to receive the rechargeable battery,
A charging terminal configured to be connected to each battery terminal of the rechargeable battery;
A battery identification reading mechanism configured to communicate with the battery identification mechanism of the rechargeable battery and for receiving the identification information;
A charging compartment including
Configured to determine the corresponding battery capacity based on the communicated identification information of the rechargeable battery;
Determine a charging current level to be applied to the rechargeable battery based on the determined corresponding battery capacity so that the battery achieves a predetermined charge that is reached within a charging period of less than 15 minutes. Configured as
A controller configured to apply a charging current having substantially the determined current level to the rechargeable battery;
Including a charger device.

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