Abstract: A cell control device according to the present invention includes: a discharge circuit that discharges each unit cell selected by the first switches among a plurality of unit cells connected in series; a charging circuit that charges each unit cell selected by the second switches among the unit cells connected in series, and; a voltage detection unit that detects a voltage of each unit cell via voltage detection lines respectively connected to positive and negative electrodes of the unit cells; an oscillator that irradiates high frequency electromagnetic radiation upon the voltage detection lines; and a charging control unit that controls switching of the first switches, thereby performing discharge of the each unit cell, and a charging control unit that controls switching of the second switches, thereby performing charging of the unit cells, based on voltages of the unit cells that are detected by the voltage detection unit.

Abstract: In an apparatus for controlling a secondary battery comprised of a plurality of cells connected in series, the apparatus includes a monitor configured to monitor an output voltage of each of the plurality of cells, and determine whether the output voltage of one of the plurality of cells reaches a preset full charge voltage. The apparatus includes a voltage equalizer configured to, when it is determined that the output voltage of one of the plurality of cells reaches the preset full charge voltage, perform a voltage equalizing task to match, with an output voltage of one specified cell in all the cells, the voltages of the remaining cells except for the one specified cell to equalize the output voltages of all the plurality of cells. The output voltage of the specified one cell is the lowest in the output voltages of all the cells.

Abstract: A battery pack includes: a battery unit in which a plurality of battery modules with a plurality of secondary batteries connected in series to each other is connected in parallel to each other so that output current; and a battery management unit. The battery management unit calculates a first allowable current value of each of the plurality of battery modules and calculates second allowable current values of the other battery modules based on the first allowable current value of one battery module from the plurality of battery modules. The battery management unit calculates a value corresponding to the sum of the first allowable current value used as the reference and the respective second current values as an allowable current value when each of the second allowable current values is equal to or smaller than the first allowable current value of the corresponding battery module.

Abstract: A device for balancing an energy accumulator, especially an energy accumulator in an on-board power supply system of a motor vehicle, is provided. The energy accumulator is formed by a cell assembly of a serial connection of a plurality of cell groups, respective balancing circuits being connected to voltage connections of respective cell groups and comprising a discharge resistor. The discharge resistor of a respective balancing circuit has a temperature-dependent resistance characteristic, and the discharge resistors of at least some of the balancing circuits are thermally intercoupled.

Abstract: A balancing method and balancing system of a battery pack is disclosed. The method includes and the system is capable of determining whether a voltage change of the battery pack is greater than a threshold during a charging or discharging period, and balancing the battery cells based on the voltage change being greater than a threshold.

Abstract: Systems and methods using the same to achieve a multiple battery charger with automatic charge current adjustment have been disclosed. The invention maintains equilibrium of charge levels during charge and discharge between all of the multiple batteries. For each battery a charger block comprising a unidirectional means and a current source for charging is assigned. The on-resistance of each charger block is automatically splitting the charge current available to the various batteries thus maintaining an equilibrium of charge levels of the batteries, i.e. supporting the battery with the lowest charge level with the highest charge current until equilibrium is reached.

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

Abstract: A battery management system for a battery pack comprising multiple battery modules is disclosed. Each of the battery modules includes multiple battery cells. The battery management system includes multiple first balancing units, multiple first controllers, a second balancing unit including multiple second balancing circuits, and a second controller coupled to the battery modules and the second balancing circuits. The first controllers are operable for controlling the first balancing units to adjust voltages of battery cells in the battery module if an unbalance occurs between the battery cells. The second controller is operable for controlling said second balancing circuits to adjust voltages of said battery modules if an unbalance occurs between battery modules.

Abstract: Provided are a cell balance device with high cell balance performance and high cell balance speed and requiring no high voltage process, and a battery system including the cell balance devices. The cell balance device includes: three terminals to be connected to secondary batteries; one terminal to be connected to a voltage hold device; three switches provided between the three terminals and the one terminal; and a receiving terminal and a transmitting terminal for a synchronization signal. Alternatively, the cell balance device includes: four terminals to be connected to secondary batteries; two terminals to be connected to a voltage hold device; six switches provided between the four terminals and the two terminals; and a receiving terminal and a transmitting terminal for a synchronization signal. The battery system includes: a plurality of secondary batteries; a plurality of voltage hold devices; a plurality of cell balance devices; and a clock generation circuit.

Abstract: A method for balancing voltage for a multi-cell battery system, in which the battery system includes at least two parallel groups of cells connected in series and in which the parallel group of cells includes at least one battery cell, includes: charging the battery system by keeping the voltage of all parallel groups of cells less than or equal to a second threshold voltage value, while at least the voltage of one group of parallel cells is less than or equal to a first threshold voltage; and while at least the voltage of one group of parallel cells is less than or equal to a second threshold voltage; and while the charging current is above a predefined minimal current. The method further includes measuring the voltage of each parallel group of cells while electrical loads are shut off and dissipating energy in each of the parallel group of cells of the amount that is represented by the voltage difference between the individual parallel group of cells and the parallel group of cells with the lowest voltage.

Abstract: Improved energy storage apparatus that is compact and less expensive is disclosed. High-voltage lines are no longer required, and heat energy can be simply dissipated from each storage module in the apparatus. A switchable inductive balancing element is electrically connected in parallel with each storage cell in each storage module, through which energy or electrical charge can be shifted among the individual storage cells in each storage module using suitably designed magnetic circuits. A power resistor and a module switch are electrically connected in parallel with the series circuit formed by the storage cells in of each storage module and the switchable inductive cell balancing elements in each module are magnetically coupled to a single switchable inductive module balancing element in the module, or each is magnetically coupled to a switchable inductive balancing element of a respective transformer.

Abstract: What is provided is a cell balance control device including: a bypass circuit including a direct circuit with a bypass resistance and a switching element, the bypass circuit being connected in parallel to each of a plurality of cells included in a battery; a cell voltage detection unit detecting a cell voltage of each of the plurality of cells; a temperature detection unit detecting a temperature of a substrate on which the bypass circuit is mounted; and a control unit controlling and computing a duty ratio of the switching element based on a value detected by the temperature detection unit and a cell voltage of a discharge-needed cell obtained by the cell voltage detection unit.

Abstract: A method of determining extent and type of capacity fade of an electrochemical cell in one embodiment includes identifying a first volume fraction of an active material in an electrode, identifying a first capacity of the first electrode at another time, identifying a second volume fraction of the first active material based upon the first capacity, identifying a first amount of the first active material lost from the first time to the second time based upon the first volume fraction and the second volume fraction, identifying a third volume fraction of an active material in another electrode, identifying a second capacity of the second electrode at a later time, identifying a fourth volume fraction of the second active material based upon the second capacity, and identifying a second amount of the second active material lost based upon the third volume fraction and the fourth volume fraction.

Abstract: A battery module voltage detector can reduce the difference in frequency response of an anti-aliasing filter for each battery module whose voltage is measured, and provide an accurate voltage measurement. The battery module voltage detector includes a plurality of switches connected to battery modules constituting a battery pack, resistors having an equal resistance value, and a filter composed of capacitors having equal capacitance and being disposed between the battery modules and the switches. The capacitors are divided into a first capacitor group and a second capacitor group which are symmetrical at the center of the battery pack. The first capacitor group is on the positive terminal side of the second battery. The second capacitor is on the negative terminal side of the battery pack. Capacitors may be connected between an output terminal of a (1+M/2)-th resistor and an N-th resistor, except a (1+m/2), the (1+M/2)-th resistor and the N-th resistor.

Abstract: A battery pack includes a plurality of cells. A discharge circuit is electrically connected to the plurality of cells. A computer processor is electrically connected to the discharge circuit and to an input device. The computer processor operates the discharge circuit to selectively connect a first and a second discharge load of the discharge circuit to the plurality of cells. A method of discharging a battery for safe disposal includes connecting a first discharge load in parallel to a first cell. A first voltage across the first cell is monitored. A second discharge load is connected in parallel to a second cell. A second voltage is monitored across the second cell. A processor compares the first voltage and the second voltage to a predetermined cell voltage threshold. The first discharge load and the second discharge load are disconnected from the first cell and the second cell when the first and second voltages fall below the predetermined cell voltage threshold.

Abstract: A battery system utilizes a plurality of transformers interconnected with the battery cells. The transformers each have at least one transformer core operable for magnetization in at least a first magnetic state with a magnetic flux in a first direction and a second magnetic state with a magnetic flux in a second direction. The transformer cores retain the first magnetic state and the second magnetic state without current flow through said plurality of transformers. Circuitry is utilized for switching a selected transformer core between the first and second magnetic states to sense voltage and/or balance particular cells or particular banks of cells.

Abstract: A voltage balancer device has a plurality of discharge paths. Each pair of the discharge paths correspond to each secondary battery unit. Each of a pair of the discharge paths has a resistance of a different value. Discharging the voltage of each secondary battery unit is at first performed through the discharge path of a smaller resistance value. The voltage balancer device switches the currently used discharge path to another discharge path having a large resistance value at the time the voltage of the secondary battery unit nearly equal a desired voltage.

Abstract: A method for controlling a plurality of battery cells with a control circuit coupled to the plurality of battery cells, includes: supplying the control circuit with electrical energy from the coupled battery cells; determining a number of battery cells coupled to the control circuit; and automatically adapting a power consumption drawn from the battery cells in response to the number of coupled battery cells.

Abstract: A contact array arrangement which both receives charging current for charging batteries of a battery pack, and which also breaks the parallel charging contact position (contact configuration in which individual batteries of the battery pack are charged in parallel) then reestablishes series connection of the batteries when a charge electrode array is urged against the contact array arrangement and when the charge electrode array is removed. A cover covering the contact array may be connected by throughbolts to a support supporting series connection contacts such that depressing the cover by imposing a downward force (e.g., the weight of a charge electrode array), moves the series connection contacts out of contact with those contacts receiving charge current. Springs return the series connection contacts to the series condition. Charge conductors fixed to the contact array pass through or by the series connection such that a very compact device results.

Abstract: In a battery system, battery modules (3a, 3b) connected to each other in series respectively include: one or more single cells (3a1 to 3an, 3b1 to 3b-n) connected to one another in any one of series, parallel, and series-parallel; cell voltage switches (7a, 7b) for detecting voltages respectively of the one or more single cells; module monitoring control units (9a, 9b) each for monitoring the detected voltages respectively of the one or more signal cells; and communications level converter circuits (14a, 14b). The battery system includes a master unit (8a) for receiving information on the voltages respectively of the one or more single cells from the module monitoring control units via the communications level converter circuits. One of the communications level converter circuits includes a switch element (Q32) for transmitting a signal of a low-potential battery module to a high-potential battery module.

Abstract: Lower order control devices control plural battery cells configuring plural battery modules. An input terminal of the low order control device in the highest potential, an output terminal of the low order control device in the lowest potential, and a high order control device are connected by isolating units, photocouplers. Diodes which prevent a discharge current of the battery cells in the battery modules are disposed between the output terminal of the low order control device and the battery cells in the battery module on the low potential side. Terminals related to input/output of a signal are electrically connected without isolating among the plural low order control devices.

Abstract: The present invention provides a battery circuit including a first battery cell with a first parameter having a first value and a second battery cell with a second parameter having a second value. The second battery cell is coupled to the first battery cell in series. The battery circuit further includes a magnetic device operable for storing energy transferred from the first battery cell via a first winding coupled to the first battery cell and for releasing the stored energy to the second battery cell via a second winding coupled to the second battery cell if the first value of the first parameter is greater than the second value of the second parameter.

Abstract: A by-pass circuit for a battery system that disconnects parallel connected cells or modules from a battery circuit or controls the current through the parallel connected cells or modules. If a cell has failed or is potentially failing in the system, then the by-pass circuit can disconnect the cell or module from other cells or modules electrically coupled in parallel. If a cell or module has a lower capability than another cell or module, then the by-pass circuit can control the current to the cell or module to maximize the performance of the system and prevent the system from creating a walk-home condition.

Abstract: The present invention provides a power source system that increases the power supply capacity of a power source device and continuously supplies the power necessary for a load device when a power source device stops. A control unit has a state quantity setting unit that sets a first target state quantity indicating a state of charge of the power storage device that is to be a target value when charge and discharge of the power storage device are controlled. When the power source device stops, the state quantity setting unit can change the first target state quantity to a second target state quantity that is to be a target value exceeding the first target state quantity and can increase the target state quantity of the power storage device. As a result, when the power source device stops, charge and discharge of the power storage device are controlled on the basis of the target state quantity exceeding that during the operation of the power source device.

Abstract: A rechargeable battery system having a plurality of cells in series circuits for high voltage applications. Cells, cell sets and cell packs in series circuits are protected from over-charging with self-discharging devices. The rechargeable battery system is protected from over-charging and over-discharging and charging is controlled to be resumed by an over-charge/over-discharge printed circuit board or the charger.

Abstract: An automotive power supply system comprises a battery module that includes serially connected battery groups each constituted with serially connected battery cells, integrated circuits each disposed in correspondence to one of the battery groups, a control circuit, a transmission path through which the integrated circuits are connected to the control circuit and a relay circuit via which an electrical current is supplied from the battery module. In response to a start signal instructing an operation start and received via the transmission path, each integrated circuit measures terminal voltages at the individual battery cells in the corresponding battery group and executes an abnormality diagnosis. If abnormality diagnosis results provided by the integrated circuits indicate no abnormality, the control circuit closes the relay, enabling supply of electrical current from the battery module and subsequently, the control circuit receives measurement results from the integrated circuits via the transmission path.

Abstract: An end-of-discharge voltage correction section subtracts, from an end-of-discharge open voltage, the product I×RO of a discharge current I of a block and an ohmic resistance RO of the block and the product ITD×RP of a discharge current ITD obtained by performing a time delay process on the discharge current and a polarization resistance RP of the block. Then, a resulting value is set as an end-of-discharge voltage VL. The ohmic resistance RO is increased as an equivalent cycle count CY increases, and is increased as a healthy parallel number NPH decreases. An increment ?CY of the equivalent cycle count CY in each charge/discharge cycle becomes greater as a discharge depth DD increases. The healthy parallel number NPH is derived by multiplying a healthy parallel number NPHR of a reference block by the ratio of a capacity CPR of the reference block to a capacity CPS of a target block.

Abstract: A battery pack system module may include a module bypass switch for allowing charge current to bypass the battery pack system module. A charge switch and a discharge switch may be coupled with the module bypass switch. When other battery pack system modules are coupled in series with the module, balancing between modules may be achieved by allowing charge current to bypass the unbalanced modules and charge other modules. For example, when an unbalanced module is at a higher level of charge than other modules, a charge switch and a discharge switch in the unbalanced module de-activate and a module bypass switch activates to allow charge current to rapidly bring other modules into balance. The discharge switch and the charge switch allow the charging current to bypass the unbalanced module creating little or no additional heat dissipation.

Abstract: In some embodiments, a power supply system includes two power modules each configured to be electrically coupled to a set of battery cells. The set of battery cells produces a first voltage when in a first operational state, and a second voltage when in a second operational state. The second voltage is less than the first voltage. The first power module is configured to provide a third voltage to a load device that is substantially equal to the first voltage, when the set of battery cells is in the first operational state. The second power module is configured to provide a fourth voltage to the load device that is substantially equal to the first voltage, when the set of battery cells is in the second operational state.

Abstract: An apparatus for balancing a multi-cell battery pack has a plurality of switchable loads. Each of the plurality of switchable loads are associated with one of a plurality of cells of a multi-cell battery. The plurality of switchable loads discharge an associated cell in a first mode and diverts part of a charging current away from the associated cell in a second mode responsive to a drive signal. A plurality of current mode driver circuits applies the drive signal to each of the plurality of switched loads.

Abstract: The present invention discloses a battery charging controller for achieving a balanced battery charge. The battery charging controller includes a voltage divider, a switch module and a balance circuit. A reference voltage generated by the voltage divide is used to determine which battery unit in a battery module has an insufficient voltage lower than the others, so that the balance circuit controls the switch module to allow a larger current to charge a lower-voltage battery than a higher-voltage battery, so as to result in substantially the same voltage for each fully charged battery of the battery module.

Abstract: A fuel cell system that includes a fuel cell stack and an EESD electrically coupled to a common high voltage bus line. The EESD has a higher voltage output than the fuel cell stack, and thus the stack is unable to fully charge the EESD, for example, at system shut-down. In order to allow the fuel cell stack to fully charge the EESD, the EESD is separated into a plurality of separate electrical storage banks having lower voltage potentials. A series of contactors are provided to electrically couple the storage banks in series during normal system operation, and separately charge the storage banks using the fuel cell stack so that they are fully charged. The series of contactors can also be configured so that the storage banks can be electrically coupled in series during normal operation of the system and be electrically coupled in parallel during charging at system shut-down.

Abstract: In one embodiment, a method includes receiving a first input current from a battery through a first connection and a second connection and generating a first output current through a third connection to a first node and a fourth connection to a second node. The first and second nodes are configured to output the first output current to an energy store configured to store a charge. The method includes receiving a second input current through the third connection from the first node and the fourth connection from the second nodes and generating a second output current through the first and second connections to charge the battery.

Abstract: In one embodiment, a circuit comprising a first set of one or more semiconductor switches coupled to a first node and a first terminal of an energy store configured to store energy, and a second set of one or more semiconductor switches coupled to a second node and a second terminal of the energy store, each of the first and second sets of semiconductor switches being configured to couple to a terminal of a battery cell.

Abstract: An apparatus for balancing charge capacity of battery cell includes a voltage sensing/discharging circuit having a battery with cell group, a switching unit for selectively connecting both terminals of each battery cell to conductive lines, capacitor connected to the conductive lines, a voltage amplifying unit connected to both terminals of capacitor via a first switch, and a discharge resistance connected to both terminals of capacitor via a second switch; and a voltage balancing unit for controlling the switching unit in ON state of first switch to connect both terminals of each battery cell to the conductive lines and then sense voltage of each battery cell through the voltage amplifying unit, and controlling the switching unit in OFF state of first switch to charge voltage of balancing-requiring cell to the capacitor and then turning on the second switch to discharge charged voltage of capacitor through the discharge resistance

Abstract: A battery system is split into first and second battery subsystems. When the first battery subsystem reaches a first discharge level, the first battery system is decoupled from output terminals of the battery system and the second battery subsystem is coupled to the output terminals of the battery system.

Abstract: A state of charge optimizing device according to the present invention optimizes a state of charge of each of a plurality of cells which are connected in series to form an assembled battery, and conducts the optimization by discharging or charging a part or all of the plurality of cells so that the differences between the amount of charge after the optimization and the amount of charge in a predetermined state of charge become uniform.

Abstract: The application relates to a battery including a pack of modules, each containing rechargeable cells in series, the battery including means for measuring the voltage and/or the temperature of at least one module. According to the application, the battery includes means for computing, based on the voltage and/or temperature measured by the measuring means and on a recorded characteristic of the discharge current and/or regeneration current of the battery, a maximum discharge and/or regeneration current limit of the pack. The battery also includes a transmission means for transmitting to the outside the information on the maximum discharge and/or regeneration current limit of the pack.

Abstract: A method of balancing a state of charge (SOC) of a plurality of cells connected in series, including identifying an undercharged cell from the plurality of cells to charge, electrically connecting a positive side of the undercharged cell to a positive bus, electrically connecting a negative side of the undercharged cell to a negative bus, electrically connecting an inductor to a voltage source during a first time period; electrically disconnecting the inductor from the voltage source in response to an elapse of the first time period, and maintaining the disconnection of the inductor from the plurality of cells for a second time period corresponding generally to the time for the inductor to discharge energy to the undercharged cell.

Abstract: Provided are a battery state monitoring circuit and a battery device which are capable of inhibiting discharge without enabling an overdischarge cell balance function when an overcurrent detection circuit detects a discharge overcurrent, without the need for an additional terminal of the battery state monitoring circuit. A detection signal of the overcurrent detection circuit is input to each of a communication terminal for overdischarge signal and a communication terminal for overcharge signal included in the battery state monitoring circuit provided on a side of the overcurrent detection circuit. An overdischarge cell balance circuit outputs a cell balance signal when an overdischarge detection signal indicates an overdischarge non-detected state, an overdischarge signal indicates an overdischarge detected state, and an overcharge signal indicates an overcharge non-detected state.

Abstract: An electrochemical storage device including a plurality of electrochemical cells connected electrically in series. Each cell includes an anode electrode, a cathode electrode and an aqueous electrolyte. The charge storage capacity of the anode electrode is less than the charge storage capacity of the cathode.

Abstract: A battery pack, or battery pack module, is provided that achieves improved battery pack performance, system reliability and system safety while impacting only a small region of the battery pack/battery module, and thus having only a minor impact on battery pack cost, complexity, weight and size. The battery pack/battery module is designed such that the fusible interconnects associated with a single battery, or a specific fusible interconnect associated with a single battery, will be the last interconnect(s) to fuse during a short circuit event. The risk of sustained arcing for the predetermined interconnect(s) is minimized through the use of rapid clearing interconnects. As a result, the risk of damage and excessive heating is also minimized.

Abstract: A method is provided that achieves improved battery pack performance, system reliability and system safety while impacting only a small region of the battery pack/battery module, and thus having only a minor impact on battery pack cost, complexity, weight and size. The battery pack/battery module is designed such that the fusible interconnects associated with a single battery, or a specific fusible interconnect associated with a single battery, will be the last interconnect(s) to fuse during a short circuit event. The risk of sustained arcing for the predetermined interconnect(s) is minimized through the use of rapid clearing interconnects. As a result, the risk of damage and excessive heating is also minimized.

Abstract: An electric storage device is disclosed, this device can balance voltages across each one of energy storage devices with each other in a short time even if the voltages disperse in a wide range, and also it can reduce needless power consumption. This device includes the energy storage devices and an equalizing voltage circuit coupled in parallel with the energy storage devices. The equalizing voltage circuit includes a balancing resistor, a balancing switch coupled between respective energy storage devices and respective balancing resistors, a discharging resistor coupled in parallel with the respective energy storage devices and having a smaller resistance value than the balancing resistor, and a discharging switch coupled between the respective energy storage devices and the respective discharging resistors.

Abstract: A secondary battery pack is described that is rechargeable and has a large capacity. The secondary pack has multiple battery units and at least one controller. Each battery unit of the battery pack includes a cell unit and a cell balancing system. In one embodiment, the cell balancing system has at least three detachable connections for connecting the cell balancing system to the cell unit, the controller or to other cell balancing units. The connections allow the cell balancing systems to be detached from the battery units and reused.

Abstract: A temperature detection portion 41 captures temperature detection values detected by a plurality of temperature sensors T disposed at prescribed positions of a battery portion 2 with a prescribed period, to detect the state of the battery portion 2. An abnormality judgment portion 42 compares the temperature detection values detected by the temperature detection portion 41 with a threshold value determined in advance, to judge whether the state of the battery portion 2 is abnormal. In a case where the abnormality judgment portion 42 judges that the battery portion 2 is abnormal, a charge/discharge control portion 43 causes a switching element 5 to operate in an on/off sequence set in advance, and then turns off the switching element 5.

Abstract: This disclosure includes battery systems and operational methods. According to one aspect, a battery system includes conversion circuitry, a plurality of main terminals configured to be coupled with a load, a charger and a plurality of rechargeable battery modules which are coupled in series with one another intermediate the main terminals, switching circuitry configured to couple a first of the battery modules with an input of the conversion circuitry, and the conversion circuitry being configured to modify an electrical characteristic of electrical energy received from the first of the battery modules and to output the electrical energy having the modified characteristic to a second of the battery modules.

Abstract: A system and method for charging an undercharged cell of a bank of series connected cells utilizes a charging circuit. The charging circuit includes an inductor that receives current from the entire bank of cells and then provides current to the undercharged cell. Pulse width modulation is utilized to turn the switches on and off to regulate the current that flows to the inductor and thus is provided to the undercharged cell.

Abstract: A device for balancing a plurality of at least two batteries or cells of a multicell battery comprises a multicell battery and a battery management system with a balancing circuit. Thereby all individual battery cells are connected to the battery monitoring system, wherein the battery monitoring system measures single cell voltage as well as the battery temperature and the current. The battery monitoring system is able to discern the lowest cell voltage and to discern a number of cells having a voltage higher than a determined maximum allowable voltage, which will be balanced until the charge imbalance decreases to an acceptable amount. The battery management system is active during charging and discharging of the multicell battery and the thresholds vary with the state of the battery.

Abstract: The present invention relates to a charge equalization apparatus, in which series-connected batteries are divided into modules having certain sizes, and intra-module charge equalization and inter-module charge equalization are simultaneously performed, thus improving charge equalization performance and reducing the circuit size.