JP2014050269A - Equal charging system for battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that, when a battery pack is configured using eclectic cells having non-uniform characteristics as a battery, charged states of all of the electric cells are not same, and when one of the electric cells is insufficiently charged, the battery pack cannot sufficiently exert the performance as the entire battery pack.SOLUTION: An equal charging system for a battery pack that comprises a plurality of secondary batteries connected in series comprises: one electricity storage element connected to the secondary batteries in parallel; a switcher sequentially connecting the one electricity storage element to one of the secondary batteries; and a control device controlling the switching operation of the switcher. In the equal charging system, an electric double layer capacitor or a secondary battery is used as the electricity storage element.

Description

  The present invention relates to an assembled battery system in which a plurality of secondary batteries are connected in series, and more particularly to charge / discharge control of the assembled battery.

  Conventionally, batteries are used in various products such as mobile PCs, personal digital assistants, and digital video cameras. This type of electronic device has advanced functionality and consumes a relatively large amount of power. For this reason, a battery used in such an electronic device requires a large electric capacity, and thus an assembled battery in which a plurality of unit cells are connected is often used. The assembled battery is configured by storing a predetermined number of single cells in a battery case.

In recent years, batteries are also mounted on vehicles such as hybrid vehicles. Such a battery is required to have a larger electric capacity than that used in an electronic device. For example, some batteries installed in hybrid vehicles require a voltage of 201.6 V. To obtain this voltage, for example, 28 units of 7.2 V assembled batteries in which 6 cells of 1.2 V are connected in series are used. A battery module is formed by connecting in series, and a battery stack in which a total of 168 unit cells are connected in series is used.
Moreover, in the ground electrical storage equipment, in order to ensure a larger battery capacity, battery modules connected in series may be used in parallel connection.

  The characteristics of the unit cells constituting such an assembled battery are not uniform, and the charge state (SOC: State of Charge) varies due to repeated charge and discharge. For this reason, when any one unit cell is in a fully charged state, in order to prevent overcharging, it is necessary to stop charging even if the other unit cells are not fully charged. Further, when the unit cell with the lowest charging depth reaches the discharge limit, it is necessary to stop the discharge even if other unit cells have a remaining amount in order to prevent overdischarge. If it does so, an assembled battery will not exhibit sufficient performance.

  As means for coping with such a problem, Patent Document 1 discloses a secondary battery charge / discharge device including a plurality of secondary batteries and a power storage unit in which a plurality of capacitors are connected in series. When charging a secondary battery by discharging, a capacitor selected from a plurality of capacitors is connected to a secondary battery selected from a plurality of secondary batteries, and when charging a power storage unit by discharging the secondary battery, The secondary battery is sequentially connected to a plurality of capacitors for charging. In addition, in the following description, when referring to one battery in comparison with the assembled battery, it may be referred to as a single battery, and generally referred to as a secondary battery.

  Patent Document 2 discloses a technique for preventing overcharging and suppressing SOC variation between single cells by providing a bypass circuit connected in parallel to a secondary battery constituting the assembled battery. Furthermore, a technique (for example, Patent Document 3) for preventing variation in the remaining amount of charge using optical communication and a technique for performing uniform discharge using a temperature sensor (for example, Patent Documents 4 and 5) are disclosed. .

JP 2012-70487 A JP 2012-43682 A JP2011-78201A JP 2007-325458 A JP-A-8-98417

  Since the characteristics of the individual cells constituting the assembled battery are not necessarily uniform, even if the entire assembled battery is charged and discharged, the charged state and the discharged state of each single battery are not the same. Thus, if the charging state or discharging state of each unit cell constituting the assembled battery is different, when charging the entire assembled battery, an overcharged unit cell or an insufficiently charged unit cell occurs, The overall performance of the battery is reduced. Therefore, when charging an assembled battery, it is necessary to equalize and charge the charging state of each unit cell constituting the assembled battery.

  Thus, when an assembled battery is configured using a large number of unit cells that have variations in characteristics as a unit cell, any unit cell pulls the entire leg, so that the performance as an assembled cell is improved. Cannot fully demonstrate. When charging an assembled battery, an insufficiently charged unit cell or an overcharged unit cell is generated. As a method for eliminating the variation in the state of charge, it is possible to temporarily align the state of charge by fully charging all the batteries individually or conversely emptying them. However, this requires a special work (for example, Patent Document 1) and takes time. In addition, it is possible to equalize the charging state of the unit cell by overcharging or overdischarging the assembled battery, but the unit cell with a small charge depth is overdischarged, and the unit cell with a large charge depth is overdischarged. There is a problem that battery charging is shortened.

  The present invention has been made in view of the problems as described above, and can prevent overcharging of the cells constituting the assembled battery and suppress variation in the state of charge (SOC) between the cells. A battery assembly charging system is provided.

In order to achieve the above-described object, an assembled battery equal charging system according to the present invention includes a storage battery connected in parallel to the secondary battery in an assembled battery in which a plurality of secondary batteries are connected in series, A switch for sequentially connecting a storage element to the secondary battery, and a control device for controlling a switching operation of the switch (Claim 1).
According to this configuration, the power storage element only needs to have a function of storing electricity. A secondary battery or a capacitor may be used. Since the voltage of the unit cell is low, it is connected in series to form a high voltage power source as an assembled battery.

In the battery assembly equal charging system according to the present invention, the switch connects / disconnects the positive terminal of the secondary battery and one terminal of the storage element, and the negative terminal of the secondary battery. And a negative electrode side switch for connecting / disconnecting the other terminal of the electric storage element, and connecting the positive electrode terminal of the adjacent secondary battery and the positive electrode terminal of the electric storage element after the positive electrode side switch is interrupted. And it is preferable to connect the negative electrode terminal of the adjacent secondary battery and the negative electrode terminal of the electricity storage element after the negative electrode side switch is shut off (Claim 2).
According to this configuration, the changeover switch may be a mechanical relay (relay), and is preferably configured by a semiconductor switch. When the power storage element has polarity, in the above, one terminal is a positive electrode side and the other is a negative electrode side terminal.

In the battery pack equal charging system according to the present invention, the control device includes a timer circuit, and the positive electrode side switch and the negative electrode side switch perform a switching operation in synchronization with a signal from the timer circuit. (Claim 3).
According to this configuration, the secondary battery is sequentially connected to the storage element at regular time intervals. This time interval is determined by the time required for charge transfer between the secondary battery and the power storage element.

In the assembled battery equal charging system according to the present invention, the control device includes a sequence switching circuit, and the secondary battery constituting the assembled battery is connected to the storage element based on a command from the sequence switching circuit. It is preferable that they are sequentially connected (claim 4).
According to this configuration, connection / cutoff control of a number of positive side switches and negative side switches constituting the switch is performed by a command from the sequence switching circuit.

In the battery pack equal charging system according to the present invention, the control device includes a built-in determination circuit for checking a variation in a charged state of the secondary battery, and the operation of the sequence switching circuit is determined by a signal from the determination circuit. It is preferable to stop the operation (claim 5).
According to this configuration, the determination circuit is a circuit that determines that the secondary battery has reached an equal state of charge. An equal state of charge is determined by variations in the state of charge of the secondary battery. When the variation decreases, the sequence switching circuit stops its operation.

In the battery assembly equal charge system according to the present invention, a voltmeter is attached to the secondary battery, and the control device includes an SOC calculation circuit that receives the signal from the voltmeter and calculates the SOC. It is preferable that the determination circuit operates in response to a signal from the SOC calculation circuit.
According to this configuration, the state of charge of the secondary battery is determined based on the SOC obtained from the voltage of the secondary battery.
In the battery assembly equal charging system according to the present invention, it is preferable that the power storage element is an electric double layer capacitor.
In the battery assembly equal charging system according to the present invention, the power storage element may be a secondary battery.

An equal charge system for an assembled battery according to the present invention includes a charger for charging an assembled battery formed by connecting a plurality of single cells in series, a microcomputer, a voltage detector for measuring the voltage of the single battery, A charging system provided with a cell selection circuit comprised of a number of switches between an assembled battery and the charger, wherein the power of the charger is supplied from the assembled battery, and the cell selection circuit By connecting / disconnecting the switch based on a computer command, one or more of the unit cells are selectively connected to the charger, or one of the unit cells is selectively connected to the voltage detector. It is preferable that a single cell connected and selected by the voltage detector is lower than a predetermined value is selected by the cell selection circuit and connected to the charger for charging.
In the battery assembly equal charge system according to the present invention, it is preferable that the single cells selected by the cell selection circuit are a plurality of single cells connected in series with each other, and the plurality of single cells are charged simultaneously ( Claim 10). According to this structure, the continuous cell connected in series is charged simultaneously.
The method for equally charging an assembled battery according to the present invention measures terminal voltages of all the cells constituting the assembled battery, calculates an average value of the measured voltage values, and calculates a predetermined voltage from the calculated average value. A unit cell that is as low as possible is selected, and the selected unit cell is simultaneously charged with a constant current.

  The present invention corrects or equalizes the variation in the state of charge between single cells by preventing overcharge and overdischarge of the single cells of the components in a battery pack in which a plurality of secondary batteries are connected in series. Provided is an assembled battery system that can be used.

In the equal charge system of an assembled battery concerning the present invention, it is a drawing explaining the connection situation of an assembled battery, a switch, and an electrical storage element. It is drawing for demonstrating operation | movement of a switch. It is drawing explaining the connection condition in case a switch is a rotary switch. It is a systematic diagram explaining the apparatus structure of the equal charge system of the assembled battery which concerns on this invention. It is drawing which shows the example of the charge characteristic (SOC) of a cell. It is a control system diagram of a balancer. It is a circuit block diagram of a balancer. It is a flowchart for demonstrating operation | movement of a balancer.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments.

  FIG. 1 shows the connection status of the assembled battery 1, the switch 3 and the storage element 4. The assembled battery 1 is configured by connecting a plurality of single cells 2 in series. In FIG. 1, an assembled battery is composed of n single cells C1 to Cn. The electricity of the assembled battery 1 can be taken out from the output terminals provided at both ends via a cable (not shown). A voltmeter 8 is attached to each unit cell 2, and the terminal voltage of each unit cell 2 can be measured. In addition, a thermometer 9 is attached inside the assembled battery 1 so that the temperature of the unit cell 2 located approximately in the center can be measured.

Both ends of the unit cell 2 are connected to a unit cell terminal 21 provided in the assembled battery 1 via a wiring 30. Here, the positive electrode side wiring 30 and the single cell terminal 21 of the unit cell 2 are also used as the negative electrode side wiring 30 and the single cell terminal 21 of the adjacent unit cells.
A switch 3 is disposed between the assembled battery 1 and the storage element 4. The selector 3 is composed of a number of changeover switches 18.
The storage element 4 is composed of an electric double layer capacitor, and both ends thereof are connected to the switch 3 via the storage element terminal 23.

  As shown in FIG. 1, the switch 3 is composed of 2n selector switches 18. The switch 3 can connect or block the n + 1 unit cell terminals 21 and the two power storage element terminals 23. In more detail, one terminal (the upper terminal in FIG. 1) of the terminals on both ends of the negative-side changeover switch 18b is connected to the negative electrode side of the unit cell 2. The other terminal (the lower terminal in FIG. 1) of the changeover switch 18 b is connected to the power storage element terminal 23 b of the power storage element 4. One terminal of the positive side changeover switch 18 a is connected to the positive side of the unit cell 2, and the other terminal of the changeover switch 18 a is connected to the power storage element terminal 23 a of the power storage element 4. In FIG. 1, all the changeover switches 18 are in an open circuit state, and the unit cell 2 and the storage element 4 are not connected.

  Next, the switching operation of the switch 3 shown in FIG. 1 will be described with reference to FIG. In FIG. 2A, the leftmost switch and the third switch from the left are closed, and both ends of the leftmost unit cell C <b> 1 are connected to both ends of the storage element 4 via the switch 3. If the electric potential (terminal voltage) of the unit cell C1 is high, the unit cell C1 is discharged, the electric charge moves to the electric storage element 4, and the electric storage element 4 is charged. On the contrary, if the electric potential of the unit cell C1 is low, the electric charge moves to the unit cell C1, and the unit cell C1 is charged. When there is no potential difference, charge transfer is eliminated.

  After a predetermined time has elapsed, the switch state of the switch 3 shifts to the state shown in FIG. In this state, all the switches 18 are in an open circuited state, and the storage element 4 is completely disconnected from the unit cell. In this state, the voltage across the storage element 4 and the voltage across the cell C1 are substantially equal. The connection state shown in FIG. 2B is a transient state in which the connection state in FIG. 2A transitions to the connection state in FIG. 2C, and is a short time.

  Next, as shown in FIG. 2C, the second switch and the fifth switch from the left are closed, and the storage element 4 is connected to the unit cell C2 adjacent to the unit cell C1. At this time, if the terminal voltage of the storage element 4 is higher than the terminal voltage of the unit cell C2, the charge of the storage element 4 moves to the unit cell C2, and conversely, if the voltage of the storage unit 4 is lower than the voltage of the unit cell C2, The electric charge of the unit cell C <b> 2 moves to the storage element 4. What is important here is that when the switch 18 shifts from the connection state of FIG. 2 (a) to the connection state of FIG. 2 (c), as shown in FIG. It is that you are.

  The switching operation as described above is sequentially performed for all the unit cells 2 constituting the assembled battery 1. Although the time during which the cell 2 and the storage element 4 are connected has been described as a predetermined time, specifically, this time is approximately 4 of the circuit time constant (T) in the closed state of the cell 2 and the storage element 4. It is doubled. The circuit time constant (T) is obtained as the product (T = RxC) of the internal resistance (R) and the capacitance (C) of the electric double layer capacitor.

  1 and 2, the case where the power storage element 4 is realized by an electric double layer capacitor has been described. However, the power storage element 4 may be a secondary battery of the same type as the single battery 2. However, when the storage element 4 is a secondary battery, the polarity of the storage element 4 is such that the positive electrode of the storage element 4 and the positive electrode of the unit cell 2 are connected, and the negative electrode of the storage element 4 and the negative electrode of the unit cell 2 are Must be connected.

  Next, another embodiment according to the present invention will be described. FIG. 3 shows a connection state when the switch 3 is constituted by the rotary switch 25. The rotary switch 16 shown in FIG. 3 is composed of rotary switches 25a and 25b composed of two circuits of upper and lower two stages. The upper and lower two-stage circuits operate in conjunction with each other. By rotating the rotary switch 16, the center terminal c is sequentially connected to the peripheral terminals (1, 2, 3,...). In FIG. 3, a secondary battery is used as the power storage element, but an electric double layer capacitor may be used.

  The storage element 4 is connected to the center terminals c of the two circuits of the rotary switch 16 via the storage element terminal 23, respectively. The cell terminals 1 to n are connected to the peripheral terminals of the negative-side rotary switch 25a. The cell terminals 2 to n + 1 are connected to the peripheral terminal c of the positive side rotary switch 25b. In the middle of switching, the center terminal c is not connected to any peripheral terminals and is open. By rotating the rotary switch 16, the storage element 4 is sequentially connected to the cells C <b> 1 to Cn. In FIG. 3, the cell C <b> 2 is connected to the power storage element 4.

  The switching device 3 shown in FIG. 1 is illustrated and described with respect to the case where the switch is configured by a mechanical relay contact. However, the switch used for the switching device 3 is preferably configured by a semiconductor switch. If it is a semiconductor switch, it is highly reliable and does not require maintenance.

  Next, the operation and effect of the present invention will be described with reference to a control system diagram of the assembled battery equal charging system shown in FIG. The voltmeter 8 and the thermometer 9 attached to the assembled battery 1 are connected to the control device 5 via the transmitter 6. The transmitter 6 is an instrument often used in industrial instrumentation equipment, and converts a signal from a detector (for example, a voltmeter or a thermometer) into a 4-20 mA current signal and transmits it to a control device or the like. .

  The control device 5 includes an SOC calculation circuit 14, a determination circuit 13, a sequence switching circuit 12, and a timer circuit 11. Signals from the voltmeter 8 and the thermometer 9 are transmitted to the SOC calculation circuit 14 in the control device 5. The SOC calculation circuit 14 calculates the state of charge (SOC) of each unit cell 2 based on the voltage signal from the voltmeter 8 and the temperature signal from the thermometer. The state of charge of the battery is represented as an SOC characteristic diagram as shown in FIG. The SOC characteristics shown in FIG. 5 are relative to the reference temperature, and it is necessary to correct the battery temperature. That is, the SOC is calculated from the battery voltage and temperature using the SOC characteristics of the battery.

  Based on a switching command from the sequence switching circuit 12 of the control device 5, opening / closing of a switch group constituting the switching device 3 is controlled. Specifically, the sequence switching circuit 12 sends an open / close command signal to the switch group constituting the switch 3. Thereby, the switch 3 selectively connects both ends of the unit cell 2 to both ends of the power storage element 4. FIG. 2 shows the switching from the unit cell C1 to the unit cell C2. The switch group is opened / closed according to the procedure of (a) → (b) → (c), and both ends of the unit cell C2 are connected to the storage element 4. Connected to both ends. The timer circuit 11 sends a time-up signal to the sequence switching circuit 12 at a predetermined time interval. The cell 2 is switched in synchronization with this time-up signal. The timer circuit is composed of a transmitter and a counter, but other types may be used as long as they measure a predetermined time. Here, the predetermined time is a predetermined time, which is at least four times the circuit time constant, and is determined in consideration of the switching operation time of the switch. You may decide based on the test.

  As described above, the sequence switching circuit 12 sequentially switches the unit cells 2 connected to the storage element 4 at predetermined time intervals. When the switching proceeds to the last unit cell Cn of the n unit cells, the process returns to the first unit cell C1 and the switching is performed. The determination circuit 13 determines whether or not to continue the switching operation and informs the sequence switching circuit 12. If the “continuation” signal is ON from the determination circuit 13, the sequence switching circuit 12 sends an open / close signal to the switch group of the switch 3 in response to the time-up signal from the timer circuit 11, and the storage element 4 Is switched from the unit cell Ci to the unit cell Ci + 1. When the “continuation” signal from the determination circuit 13 is turned OFF, the sequence switching circuit 12 sets all the switch groups of the switch 3 to the “open” state, and ends the switching operation.

  If the determination circuit 13 determines that the charging state of each unit cell 2 has become uniform based on the signal from the SOC calculation circuit 14, it stops sending the “continue” signal, and the charging state of each unit cell 2 is uniform. If it is determined that it has not been converted, a “continuation” signal is transmitted. As a determination method, determination is made when the SOCs of all the unit cells 2 are within 5% above and below the average value. Other methods may be used.

  The equal charge system shown in FIG. 4 is a method of charging a plurality of unit cells constituting an assembled battery equally using an electric double layer capacitor or a unit cell. According to this method, even charging can be ensured, but charging takes time because the single cells are switched and charged one by one. Therefore, we have succeeded in developing a method for charging a plurality of single cells simultaneously.

  FIG. 6 shows a control system diagram of a balancer that uniformly charges the cells constituting the assembled battery. An assembled battery 51 in which the unit cells 50 are connected in series is connected to the balancer 60 via a wiring 73. The balancer 60 includes a cell selection circuit 61, a charger 63, and a microcomputer 66 as main components. DC power can be supplied from the assembled battery 51 to the charger 63 via the power switch 55. When a battery stack is configured by connecting a plurality of assembled batteries in series, DC power may be supplied from the battery stack to the charger 63.

  The charger 63 is connected to the cell selection circuit 61 via the wiring 72. The cell selection circuit 61 is connected to the assembled battery 51 via the wiring 73. Further, a voltage detector 64 is connected to the output of the charger 63 so that the voltage of the unit cell (cell) 50 can be measured. The output of the voltage detector 64 is connected to a 12-bit AD converter 65, and the microcomputer 66 can read the voltage of a single battery. The cell selection circuit 61 receives a command from the microcomputer 66 via the wiring 71 and selectively connects the unit cell 50 and the charger 63 constituting the assembled battery 51. Similarly, the cell selection circuit 61 receives a command from the microcomputer 66 and selectively connects the unit cell 50 and the voltage detector 64. An LED display 67 is connected to the microcomputer 66 to display the operating status of the balancer 60.

  Next, the circuit of the balancer 60 will be described. FIG. 7 is a diagram illustrating a circuit configuration of the balancer 60. There is no particular limitation on the number of assembled batteries handled by one balancer 60 except for a problem with withstand voltage. In FIG. 7, a battery stack 52 including two assembled batteries 51 is connected to the balancer 60. The upper assembled battery 51a is configured by connecting 20 unit cells 50 of C1 to C20 in series. The lower assembled battery 51b is configured by connecting 20 unit cells 50 of C21 to C40 in series. Both ends of each unit cell 50 can be connected to a charger 63 via a cell selection circuit 61. The cell selection circuit 61 is composed of a large number of semiconductor switches, and is turned on / off based on a command from the microcomputer 66.

  For example, when charging is performed, if the microcomputer 66 selects C18 and C19, the switch 18p and the switch 19n in the figure are turned on, and the other switches are kept off. Thereby, the plus pole of the unit cell C18 is connected to the plus side of the charger 63, and the minus pole of the unit cell C19 is connected to the minus side of the charger 63. The cells C18 and C19 are in a chargeable state. The charger 63 receives a command from the microcomputer 66 and supplies a predetermined current (4A in this embodiment) to the single cells C18 and C19. That is, the charger 63 operates as a constant current source, and charges the cell 50 with a constant current. After the variation in the charged state of the unit cell 50 is eliminated, the charger 63 stops charging.

  When measuring the voltage of the unit cell 50, if the microcomputer 66 selects C18, the switches 18p and 18n in the figure are turned ON, and the other switches are kept OFF. Thereby, the plus pole of the unit cell C18 is connected to the plus side of the voltage detector 64, and the minus pole of the unit cell C18 is connected to the minus side of the voltage detector 64. As a result, the voltage of C18 is detected by the voltage detector 64. It is converted into a digital signal by the AD converter 65 and can be read into the microcomputer 66. When the voltage of the unit cell 50 is being detected, the charger 63 is in an OFF state according to a command from the microcomputer 66. At this time, the output impedance of the charger 63 is very high and no current flows out, so that no error occurs in voltage detection.

  The operation of the balancer 60 will be described using the flowchart shown in FIG. In step 10 (hereinafter, step is abbreviated as S), the voltages (cell voltages) of all the unit cells 50 constituting the assembled battery 51 are measured. In S20, the battery packs are arranged in ascending order of cell voltage. In the embodiment shown in FIG. 7, the battery packs 51a and 51b are arranged in ascending order of cell voltage. In S30, the number of cells (single cells) having a voltage lower than the reference voltage is checked. Here, the reference voltage means a voltage 5% lower than the average of the voltage values of the cells constituting the assembled battery.

  If the number of consecutive cells lower than the reference voltage is 4 or more in S40, the process proceeds to S100, and otherwise, the process proceeds to S50. If the number of cells lower than the reference voltage is 3 in S50, the process proceeds to S110, and if not, the process proceeds to S60. If the number of consecutive cells lower than the reference voltage is 2 in S60, the process proceeds to S120, and if not, the process proceeds to S70. If the number of cells lower than the reference voltage is 1 in S70, the process proceeds to S130, otherwise returns to the start.

In S100, four continuous cells (single cells) are selected in ascending order of voltage, and the process proceeds to S140. In S110, three cells lower than the reference voltage are selected, and the process proceeds to S140. In S120, two cells lower than the reference voltage are selected, and the process proceeds to S140. In S130, one cell lower than the reference voltage is selected, and the process proceeds to S140. In S140, charging of the selected cell is started at 4A. In S150, after one minute has passed, the process proceeds to S160. In S160, charging is stopped and the process returns to the start.
As described above, by using the balancer 60 according to the present invention, a plurality of cells can be charged at a time, and an improvement in productivity can be expected.

  The assembled battery equal charging system according to the present invention is applicable not only to industrial use but also to consumer use assembled batteries.

DESCRIPTION OF SYMBOLS 1 assembled battery 2 cell 3 switch 4 storage element 5 control device 6 transmitter 8 voltmeter 9 thermometer 11 timer circuit 12 sequence switch circuit 13 judgment circuit 14 SOC calculation circuit 16 rotary switch 18 selector switch (a; positive side) B; negative electrode side)
21 battery cell terminal 23 storage element terminal 25 rotary switch 27 positive electrode side switch 28 negative electrode side switch 30 wiring 50 single cell 51 assembled battery 52 battery stack 55 power switch 60 balancer 61 cell selection circuit 63 charger 64 voltage detector 65 AD converter 66 Microcomputer 67 LED display 71, 72, 73 Wiring

Claims (11)

In an assembled battery in which a plurality of secondary batteries are connected in series,
A storage element connected in parallel with the secondary battery;
A switch for sequentially connecting the storage element to the secondary battery;
A battery pack equalizing system including a control device for controlling a switching operation of the switch   The switch connects / disconnects the positive terminal of the secondary battery and one terminal of the power storage element, and connects / disconnects the negative terminal of the secondary battery and the other terminal of the power storage element. A negative electrode side switch that shuts off, connects the positive electrode terminal of the secondary battery adjacent to the positive electrode terminal of the power storage element after the positive electrode side switch is shut off, and is adjacent to the negative electrode side switch after the cutoff. The battery assembly equal charging system according to claim 1, wherein a negative electrode terminal of a secondary battery and a negative electrode terminal of the power storage element are connected.   3. The control device according to claim 1, wherein the control device includes a timer circuit, and the positive electrode side switch and the negative electrode side switch perform a switching operation in synchronization with a signal from the timer circuit. Equal battery charging system.   4. The control device according to claim 1, wherein the control device includes a sequence switching circuit, and the secondary batteries constituting the assembled battery are sequentially connected to the power storage element based on a command from the sequence switching circuit. An equal charging system for an assembled battery according to one item.   The determination circuit for checking the variation in the charging state of the secondary battery is built in the control device, and the operation of the sequence switching circuit is stopped by a signal from the determination circuit. The equal charge system of the assembled battery as described in the item.   A voltmeter is attached to the secondary battery, and the control device includes an SOC calculation circuit that receives a signal from the voltmeter and calculates an SOC, and receives the signal from the SOC calculation circuit to The equal charging system for an assembled battery according to any one of claims 1 to 5, wherein the determination circuit operates.   The battery assembly equal charging system according to claim 1, wherein the storage element is an electric double layer capacitor.   The battery assembly equal charging system according to claim 1, wherein the storage element is a secondary battery. A charger for charging an assembled battery formed by connecting a plurality of single cells in series;
A microcomputer,
A voltage detector for measuring the voltage of the unit cell;
A charging system provided with a cell selection circuit comprised of a number of switches between the assembled battery and the charger,
The charger is powered from the battery pack,
The cell selection circuit selectively connects one or two or more of the unit cells to the charger by connecting / disconnecting the switch based on a command from the microcomputer, or alternatively, connects the unit cell to one unit. Selectively connect to the voltage detector,
An equal charging system for an assembled battery in which a single cell whose voltage detected by the voltage detector is lower than a predetermined value is selected by the cell selection circuit and connected to the charger for charging.   10. The assembled battery equal charging system according to claim 9, wherein the unit cells selected by the cell selection circuit are a plurality of unit cells connected in series with each other, and the plurality of unit cells are charged simultaneously. Measure the terminal voltage of all the cells that make up the battery pack,
Calculate the average value of the measured voltage value,
Select a single cell that is lower than the calculated average value by a predetermined voltage,
An equal charging method for an assembled battery in which selected cells are simultaneously charged with a constant current.

Images