JP7320177B2 - power storage device - Google Patents

Description

It relates to a power storage device.

Conventionally, in a power storage device equipped with a power storage element such as a lithium-ion battery, when an abnormality such as overcharge, overdischarge, or overcurrent is detected, a circuit breaker is turned off (opened) to protect the power storage element from the abnormality. (See Patent Document 1, for example).

JP 2018-26923 A

When the circuit breaker is turned off to protect the storage element from an abnormality, the circuit breaker must be turned on (closed, closed) afterward to enable the storage element to be used again. When turning on the circuit breaker, if the cause of the abnormality is not eliminated before turning on the circuit breaker, there is a possibility that the power storage element will fall into an abnormal state again.
However, in a power storage device that does not have a function of communicating with an external device, sufficient consideration has not been given to turning on the circuit breaker while reducing the possibility that the power storage element will fall into an abnormal state again.

In the present specification, in a power storage device that does not have a function of communicating with an external device, after an abnormality of the power storage element is detected and the circuit breaker is turned off, the possibility that the power storage element will fall into an abnormal state again is reduced. A technique for turning on a circuit breaker is disclosed.

A power storage device that does not have a function of communicating with an external device, comprising: a power storage element; a circuit breaker connected in series with the power storage element; a first detection circuit for detecting whether or not an element is in a charging state; and a management section, wherein the management section turns off the circuit breaker when an abnormality in the storage element is detected. a first protection process for protecting the storage element from an abnormality; and after turning off the circuit breaker by the first protection process, turning on the circuit breaker according to a detection result of the first detection circuit. A power storage device that executes a first ON process.

In a power storage device that does not have a function to communicate with an external device, after detecting an abnormality in the storage element and turning off the circuit breaker, the circuit breaker is turned on while reducing the possibility that the storage element will fall into an abnormal state again. can.

motorcycle side view Vehicle system block diagram Battery exploded perspective view Plan view of secondary battery Sectional view of AA line of FIG. Battery block diagram Circuit diagram of the first detection circuit and the second detection circuit Schematic diagram showing a state in which the alternator does not charge the secondary battery Schematic diagram showing how the alternator charges the secondary battery Schematic diagram showing a case where there is a resistor that externally short-circuits the positive electrode external terminal and the negative electrode external terminal.

(Outline of this embodiment)
A power storage device that does not have a function of communicating with an external device, comprising: a power storage element; a circuit breaker connected in series with the power storage element; a first detection circuit for detecting whether or not an element is in a charging state; and a management section, wherein the management section turns off the circuit breaker when an abnormality in the storage element is detected. a first protection process for protecting the storage element from an abnormality; and after turning off the circuit breaker by the first protection process, turning on the circuit breaker according to a detection result of the first detection circuit. A power storage device that executes a first ON process.

In the following explanation, not only when an abnormality actually occurs and is detected, but also when an abnormality is foreseen (when an abnormality has not yet occurred but is judged to occur soon). It is also called "when an abnormality is detected".
When the circuit breaker is turned off to protect the storage element from an abnormality, when the circuit breaker is subsequently turned on to enable the storage element to be used again, the charger may charge the storage element depending on the abnormality that has occurred. If the circuit breaker is turned on when the battery is in a state where the battery is charged, the abnormality may occur again.
For example, a power storage device that is generally used to start the engine of a four-wheeled vehicle (hereinafter referred to as a power storage device for four-wheeled vehicles) has a function of communicating with the ECU (external device) of the four-wheeled vehicle. Whether or not the alternator (external charger) of the automobile is in a state of charging the storage element (while the engine is operating) can be determined from a signal received from the ECU. However, since a power storage device for a two-wheeled vehicle generally does not have a function of communicating with an ECU, it cannot be determined from a signal received from the ECU whether or not the alternator is in a state of charging the power storage element.
When the circuit breaker is on, it is possible to determine from the charging current whether or not the external charger is in a state of charging the storage element. It cannot be determined from the electric current.
According to the power storage device described above, although it does not have a function of communicating with an external device, it is provided with the first detection circuit. It can be detected whether there is
For this reason, if the charger is in a state where the storage element is being charged and the circuit breaker is turned on, in the event of an abnormality that may cause an abnormality to occur again, the charger will not charge the storage element (for example, when the engine is stopped). By occasionally turning on the circuit breaker, it is possible to reduce the possibility that the power storage element will become abnormal again even if it does not have the function of communicating with an external device. If the breaker is turned on while the charger is not charging the storage element, and there is a possibility that the fault will occur again, the breaker should be turned on while the charger is charging the storage element. This reduces the possibility that the power storage element will become abnormal again even if it does not have the function of communicating with an external device.
Therefore, according to the power storage device described above, even if the power storage device does not have the function of communicating with an external device, the power storage device may fall into an abnormal state again after an abnormality of the power storage device is detected and the circuit breaker is turned off. circuit breaker can be turned on with reduced noise.

The first detection circuit may be a resistance voltage dividing circuit provided in parallel with the storage element and the circuit breaker.

Although various configurations are possible as the configuration of the first detection circuit, the first detection circuit becomes complicated depending on the configuration. Using a resistive voltage dividing circuit as the first detection circuit can realize the first detection circuit with a simple configuration.

The first protection process includes a second protection process of turning off the circuit breaker when overcharging of the power storage element is foreseen, and the first ON process is performed by the second protection process. a second ON process for turning on the circuit breaker when the first detection circuit detects that the external charger is not charging the storage element after the circuit breaker is turned off; may include

When the circuit breaker is turned off to protect the storage element from overcharging, if the circuit breaker is turned on while the external charger is in a state of charging the storage element, charging of the storage element is resumed and the storage is restored. The device can lead to overcharging.
According to the power storage device described above, the breaker is turned on when the charger does not charge the power storage element, so that the breaker can be turned on while reducing the possibility of overcharging the power storage element.

The first protection process includes a third protection process of turning off the circuit breaker when overdischarge of the power storage element is foreseen, and the first ON process is performed by the third protection process. a third ON process for turning on the circuit breaker when the first detection circuit detects that the external charger is in a state of charging the storage element after the circuit breaker is turned off; may include

When the circuit breaker is turned off to protect the storage element from overdischarging, if the circuit breaker is turned on while the external charger is not charging the storage element, the storage element will not be charged and the storage element will over discharge. Discharge may occur.
According to the power storage device described above, the breaker is turned on when the charger is charging the power storage element, so that the breaker can be turned on while reducing the possibility of the power storage element being overdischarged.

The first protection processing includes fourth protection processing for turning off the circuit breaker when an overcurrent in the charging direction is detected, and the first ON processing is performed by the fourth protection processing. a fourth ON process for turning on the circuit breaker when the first detection circuit detects that the external charger is not charging the storage element after the circuit breaker is turned off; may contain.

If the charger fails, an overcurrent in the charging direction (charging overcurrent) may flow through the power storage device. If the circuit breaker is turned off to protect the storage element from charging overcurrent, charging overcurrent may flow through the storage element again if the circuit breaker is turned on while the charger is charging the storage element. .
According to the power storage device, the breaker is turned on when the charger does not charge the power storage element, so that the breaker can be turned on while reducing the possibility that charging overcurrent will flow through the power storage element again.

A power storage device used to start an engine of a motorcycle, comprising: a power storage element; a circuit breaker provided in series with the power storage element; and a positive external terminal and a negative electrode of the power storage device when the circuit breaker is off. a second detection circuit that detects the presence or absence of a resistor that externally short-circuits the external terminal; a fifth protection process for protecting the storage element from overcurrent by turning it off; and after the circuit breaker is turned off by the fifth protection process, the absence of the resistor is detected by the second detection circuit. and a fifth ON process for turning on the circuit breaker when the power storage device is activated.

If there is a resistor that externally short-circuits the positive electrode external terminal and the negative electrode external terminal, an overcurrent in the discharge direction (discharge overcurrent) flows through the storage element. When the circuit breaker is turned off to protect the storage element from discharge overcurrent, if the circuit breaker is turned on while there is a resistor short-circuiting the positive external terminal and the negative external terminal, the storage element is discharged again. It is not desirable for safety because overcurrent flows.
When the circuit breaker is on, the presence or absence of the resistor short-circuiting the positive external terminal and the negative external terminal can be determined from the discharge current, but when the circuit breaker is off, no discharge current flows. Therefore, it cannot be determined from the discharge current.
Since the power storage device includes the second detection circuit, it is possible to detect the presence or absence of the resistor that externally short-circuits the positive electrode external terminal and the negative electrode external terminal even when the circuit breaker is off. Therefore, by turning on the circuit breaker when there is no resistor short-circuiting the positive electrode external terminal and the negative electrode external terminal, an abnormality in the storage element (discharge overcurrent) is detected and the circuit breaker is turned off. After that, the circuit breaker can be turned on while reducing the possibility that the storage element will fall into an abnormal state again.

The second detection circuit may be a resistance voltage dividing circuit provided in parallel with the storage element and the circuit breaker.

Various configurations are possible as the configuration of the second detection circuit, but depending on the configuration, the second detection circuit becomes complicated. Using a resistive voltage dividing circuit as the second detection circuit makes it possible to realize the second detection circuit with a simple configuration.

The invention disclosed in this specification can be realized in various forms such as an apparatus, a method, a computer program for realizing the functions of these apparatuses or methods, a recording medium recording the computer program, and the like.

<Embodiment 1>
Embodiment 1 will be described with reference to FIGS. 1 to 8. FIG.
As shown in FIG. 1 , a battery 50 (an example of a power storage device) according to Embodiment 1 is a battery for a motorcycle mounted on a motorcycle 10 .

As shown in FIG. 2, the battery 50 is connected to a starter 10A, an alternator 10B (an example of an external charger), and accessories 10C (headlight, air conditioner, audio, etc.) mounted on the motorcycle 10. there is The battery 50 is an engine starting battery that supplies electric power to the starter 10A to start the engine. Battery 50 is charged by alternator 10B during engine operation.

While the engine of the motorcycle 10 is operating, electric power is supplied from the alternator 10B to the accessories 10C. Therefore, the battery 50 does not supply power to the accessories 10C while the engine is operating, but supplies power to the accessories 10C when the accessories 10C are used while the engine is stopped.
Generally, a motorcycle battery does not have a function of communicating with an ECU (an example of an external device) of the motorcycle 10 . The battery 50 for a two-wheeled vehicle according to Embodiment 1 also does not have the function of communicating with the ECU.

(1) Configuration of Battery As shown in FIG.
The container 71 includes a main body 73 and a lid 74 made of synthetic resin material. The main body 73 is cylindrical with a bottom. The main body 73 has a bottom portion 75 and four side portions 76 . An upper opening 77 is formed at the upper end portion by the four side portions 76 .

The housing body 71 houses the assembled battery 60 and the circuit board unit 65 . The assembled battery 60 has 12 secondary batteries 62 (an example of power storage elements). The secondary battery 62 is, for example, a lithium ion battery. The 12 secondary batteries 62 are connected in 3 parallel and 4 in series. Circuit board unit 65 includes circuit board 100 and electronic components mounted on circuit board 100 , and is arranged above assembled battery 60 .

The lid 74 closes the upper opening 77 of the main body 73 . An outer peripheral wall 78 is provided around the lid body 74 . The lid 74 has a projecting portion 79 that is substantially T-shaped in plan view. A positive electrode external terminal 51 is fixed to one corner of the front portion of the lid 74 , and a negative electrode external terminal 52 is fixed to the other corner.

As shown in FIGS. 4 and 5, the secondary battery 62 includes an electrode assembly 83 and a non-aqueous electrolyte housed in a rectangular parallelepiped case 82 . The case 82 has a case main body 84 and a lid 85 that closes the upper opening.
The electrode body 83, although not shown in detail, is provided between a negative electrode element in which an active material is applied to a base material made of copper foil and a positive electrode element in which an active material is applied to a base material made of aluminum foil. A separator made of a resin film is arranged. Each of these is strip-shaped, and is wound flat so as to be accommodated in the case main body 84 with the negative electrode element and the positive electrode element shifted to opposite sides in the width direction with respect to the separator. .

A positive terminal 87 is connected to the positive element through a positive current collector 86, and a negative terminal 89 is connected to the negative element through a negative current collector 88, respectively. The positive electrode current collector 86 and the negative electrode current collector 88 are composed of a flat plate-shaped pedestal portion 90 and leg portions 91 extending from the pedestal portion 90 . A through hole is formed in the base portion 90 . Leg 91 is connected to the positive or negative element. The positive electrode terminal 87 and the negative electrode terminal 89 are composed of a terminal main body portion 92 and a shaft portion 93 projecting downward from the center portion of the lower surface thereof. Among them, the terminal body portion 92 and the shaft portion 93 of the positive electrode terminal 87 are integrally formed of aluminum (single material). In the negative electrode terminal 89, the terminal body portion 92 is made of aluminum and the shaft portion 93 is made of copper, and these are assembled together. The terminal bodies 92 of the positive terminal 87 and the negative terminal 89 are arranged at both ends of the lid 85 via gaskets 94 made of an insulating material, and are exposed to the outside through the gaskets 94 .

The lid 85 has a pressure relief valve 95 . Pressure relief valve 95 is located between positive terminal 87 and negative terminal 89 as shown in FIG. The pressure release valve 95 opens to reduce the internal pressure of the case 82 when the internal pressure of the case 82 exceeds the limit value.

(2) Electrical Configuration of Battery As shown in FIG. 6, the battery 50 includes an assembled battery 60 and a BMU 101 (Battery Management Unit) that manages the assembled battery.

As described above, there are 12 secondary batteries 62, and 3 are connected in parallel and 4 are connected in series. In FIG. 6, three secondary batteries 62 connected in parallel are represented by one battery symbol. Battery 50 is rated at 12V.
The power line 70</b>P is a power line that connects the positive external terminal 51 and the positive electrode of the assembled battery 60 . The power line 70N is a power line that connects the negative external terminal 52 and the negative electrode of the assembled battery 60 . The negative electrode of the assembled battery 60 is connected to the signal ground G1. The assembled battery 60 uses the signal ground G1 as a reference potential. The negative external terminal 52 is connected to the body ground G2. A body ground G2 is the body of the motorcycle 10 . A body ground G2 is a reference potential of the motorcycle 10 .

BMU 101 includes current sensor 53 , voltage sensor 110 , circuit breaker 55 , detector 140 and manager 130 . The assembled battery 60, current sensor 53 and circuit breaker 55 are connected in series via power lines 70P and 70N. Current sensor 53, voltage sensor 110, circuit breaker 55, detector 140, and manager 130 are mounted on circuit board 100, and signal ground G1 of circuit board 100 is used as a reference potential (operation standard).

The current sensor 53 is positioned at the negative electrode of the assembled battery 60 and provided on the power line 70N on the negative electrode side. The current sensor 53 detects the current value and direction (charging direction or discharging direction) of the current I of the assembled battery 60 .
A voltage sensor 110 detects the voltage V of each secondary battery 62 and the total voltage of the assembled battery 60 . The total voltage of the assembled battery 60 is the total voltage of the four secondary batteries 62 .

The circuit breaker 55 is positioned at the negative electrode of the assembled battery 60 and provided on the negative power line 70N. The circuit breaker 55 has a charge FET 55A and a discharge FET 55B. The charging FET 55A and the discharging FET 55B are power semiconductor switches, more specifically N-channel field effect transistors (FETs). The source S of the charge FET 55A and discharge FET 55B is a reference terminal. Gates G of the charging FET 55A and the discharging FET 55B are control terminals. Drains D of the charge FET 55A and the discharge FET 55B are connection terminals.

The source S of the charging FET 55A is connected to the negative electrode of the assembled battery 60 . The discharge FET 55B has the source S connected to the negative external terminal 52 . The charging FET 55A and the discharging FET 55B are connected back-to-back by connecting the drains D to each other.

The charging FET 55A has a parasitic diode 56A. The forward direction of the parasitic diode 56A is the same as the discharging direction. The discharge FET 55B has a parasitic diode 56B. The forward direction of the parasitic diode 56B is the same as the charging direction.

Since the source S of the discharge FET 55B is connected to the negative external terminal 52, the body ground G2 is the reference potential. The source S of the charging FET 55A is connected to the negative electrode of the assembled battery 60 . Since the negative electrode of the assembled battery 60 is connected to the signal ground G1 of the circuit board 100, the signal ground G1 is the reference potential of the charging FET 55A.
The charging FET 55A is turned on by applying an H level voltage to the gate G, and turned off by applying an L level voltage to the gate G. The same applies to the discharge FET 55B.

The detector 140 is provided in parallel with the secondary battery 62 and the circuit breaker 55 . Specifically, the first signal line 143 provided with the detection unit 140 has one end connected to the power line 70P between the assembled battery 60 and the positive electrode external terminal 51, and the other end connected to the current sensor 53. It is connected to the power line 70N between the negative external terminal 52 and the negative electrode external terminal 52 .

The detection unit 140 detects whether or not the alternator 10B is in a state of charging the secondary battery 62 when the charging FET 55A or the discharging FET 55B is off, and when the discharging FET 55B is off, the positive external electrode is detected. The presence or absence of an external resistor that short-circuits the terminal 51 and the negative external terminal 52 is detected. A description of the detection unit 140 will be given later.

The management unit 130 has a CPU 131 , a ROM 132 and a RAM 133 . Management unit 130 manages battery 50 based on outputs of voltage sensor 110 and current sensor 53 . The management unit 130 normally applies an H level voltage to the gate G of the charging FET 55A and the gate G of the discharging FET 55B to turn on the charging FET 55A and the discharging FET 55B. When both the charging FET 55A and the discharging FET 55B are on, the assembled battery 60 can be both charged and discharged.

(3) Configuration of Detection Section As shown in FIG. 7, the detection section 140 includes a first detection circuit 141 and a second detection circuit 142 provided in parallel.

The first detection circuit 141 is a circuit that detects whether or not the alternator 10B of the motorcycle 10 is in a state of charging the secondary battery 62 when the charging FET 55A or the discharging FET 55B is off. The first detection circuit 141 is a resistor voltage dividing circuit, and includes a plurality of voltage dividing resistors R1 to R5. Voltage dividing resistors R1 and R2 are provided in series with the first signal line 143 .

A second signal line 144 branches from the first signal line 143 between the two voltage dividing resistors R1 and R2. The other end of the second signal line 144 is connected to the signal ground G1. A P-channel FET 145, a rectifying element (diode) 146, and three voltage dividing resistors R3, R4 and R5 are connected in series to the second signal line 144. FIG. A capacitor 147 is provided in parallel with the resistor R5.

A third signal line 148 branches off from the second signal line 144 between the two voltage dividing resistors R4 and R5. The other end of the third signal line 148 is connected to the voltage sensor 110 .
A fourth signal line 149 branches from between the resistor R1 and the second signal line 144 in the first signal line 143 . The other end of the fourth signal line 149 is connected to the signal ground G1. A resistor R6, a resistor R7 and an N-channel FET 150 are connected in series to the fourth signal line 149. FIG. The gate G of the FET 145 provided on the second signal line 144 is connected to the fourth signal line 149 between the resistors R6 and R7.

A gate G of the FET 150 is connected to the fifth signal line 151 . The other end of the fifth signal line 151 is connected to the management section 130 . The fifth signal line 151 is provided with a resistor R8.
A sixth signal line 152 branches from the fifth signal line 151 between the FET 150 and the resistor R8. The other end of the sixth signal line 152 is connected between the FET 150 of the fourth signal line 149 and the signal ground G1. The sixth signal line 152 is provided with a resistor R9.

When the management unit 130 applies an H level voltage through the fifth signal line 151, the FET 150 is turned on. When the FET 150 is turned on, an H level voltage is applied to the gate G of the FET 145 and the FET 145 is turned on. When the FET 145 is turned on, a voltage corresponding to the ratio of the resistance values of the voltage dividing resistors R 1 to R 5 is applied to the voltage sensor 110 via the third signal line 148 .

The second detection circuit 142 is a circuit that detects the presence or absence of an external resistor (conductor) that short-circuits the positive external terminal 51 and the negative external terminal 52 when the discharge FET 55B is off. The configuration of the second detection circuit 142 is substantially the same as that of the first detection circuit 141, except that there is no resistor corresponding to the resistor R4 of the first detection circuit 141 and that each resistor has a different resistance value. are the same as , only the reference numerals are shown and the description thereof is omitted.

Each voltage dividing resistor of the first detection circuit 141 has a resistance value set so that it can detect whether or not the alternator 10B is in a state of charging the secondary battery 62 . Each voltage dividing resistor of the second detection circuit 142 has a resistance value set so that the presence or absence of a resistor short-circuiting the positive external terminal 51 and the negative external terminal 52 can be detected.

(3-1) Detection of Whether Alternator is in Charge of Secondary Battery FIG. 8A schematically shows a state in which the alternator 10B does not charge the secondary battery 62 (while the engine is stopped). In FIG. 8A, the voltage dividing resistors R3 and R4 are indicated by one resistor symbol. As mentioned above, the battery 50 is rated at 12V. When the charging FET 55A is off, the path to which the voltage dividing resistor R2 is connected is opened, so the voltage of the battery 50, 12V, is divided according to the resistance values of the voltage dividing resistors R1 and R3 to R5. Applied to voltage sensor 110 .

FIG. 8B schematically shows a state in which the alternator 10B charges the secondary battery 62 (during engine operation). Assume here that the charging voltage of the alternator 10B is 15V. When the charging FET 55A is off, the voltage of the positive external terminal 51 is 12 V and the voltage of the negative external terminal 52 is -3 V, and the voltage difference of 15 V is divided according to the resistance values of the voltage dividing resistors R1 to R5. is applied to the voltage sensor 110.

The voltage sensor 110 measures the voltage value of the voltage applied from the first detection circuit 141 and outputs it to the management unit 130 . Management unit 130 detects whether or not alternator 10B is in a state of charging secondary battery 62 by comparing the output voltage value with a predetermined threshold value.

(3-2) Detection of Presence or Absence of Resistor Externally Short-circuiting Positive External Terminal and Negative External Terminal If there is no resistor externally short-circuiting positive external terminal 51 and negative external terminal 52, The description is omitted because it is substantially the same as the case shown.

FIG. 8C schematically shows a case where there is a resistor 160 that externally short-circuits the positive electrode external terminal 51 and the negative electrode external terminal 52 . Assume that the resistance value of the resistor 160 is about 0 to 1Ω. When the discharge FET 55B is off, the voltage of the negative external terminal 52 is approximately 12V. Therefore, the voltage difference between the positive external terminal 51 and the negative external terminal 52 is approximately 0V. Therefore, the voltage applied to the voltage sensor 110 is also approximately 0V.

The voltage sensor 110 measures the voltage value of the voltage applied from the second detection circuit 142 and outputs it to the management unit 130 . Management unit 130 detects the presence or absence of resistor 160 by comparing the output voltage value with a predetermined threshold value.

(4) Processing Executed by Management Unit Among the processing executed by the management unit 130, the SOC estimation processing, the secondary battery protection processing, and the FET ON processing will be described.

(4-1) SOC Estimation Processing The SOC estimation processing is processing for estimating the state of charge (SOC) of the secondary battery 62 by the current integration method. In the current integration method, the current sensor 53 measures the charge/discharge current of the secondary battery 62 at predetermined time intervals to measure the amount of power flowing in and out of the secondary battery 62, and by adjusting this from the initial capacity, the SOC is a method of estimating

The current integration method has the advantage of being able to estimate the SOC even while the secondary battery 62 is in use. there is a possibility. Therefore, the management unit 130 may reset the SOC estimated by the current integration method based on the open circuit voltage (OCV) of the secondary battery 62 . Specifically, since there is a relatively accurate correlation between the OCV and the SOC, even if the SOC is estimated from the OCV and the SOC estimated by the current integration method is reset with the SOC estimated from the OCV, good.
OCV is not limited to the open circuit voltage. For example, OCV may be the voltage when the current value of the current flowing through the secondary battery 62 is less than a minute reference value.

(4-2) Secondary Battery Protection Processing The secondary battery protection processing (an example of the first protection processing) is to ) is turned off to protect the secondary battery 62 from an abnormality. Here, overcharge, overdischarge, overcurrent in the charge direction (hereinafter referred to as charge overcurrent), and overcurrent in the discharge direction (hereinafter referred to as discharge overcurrent) will be described as examples of abnormalities of the secondary battery 62 .

Overcharge and overdischarge will be explained. The management unit 130 determines whether or not the estimated SOC is equal to or greater than a predetermined upper limit value and whether or not the SOC is equal to or less than a predetermined lower limit value each time the SOC is estimated by the SOC estimation process described above. . When the SOC is equal to or higher than a predetermined upper limit, management unit 130 assumes that overcharging is foreseen and turns off charging FET 55A (an example of second protection processing). Similarly, when the SOC is equal to or lower than a predetermined lower limit, management unit 130 assumes that overdischarge is foreseen and turns off discharge FET 55B (an example of the third protection process).

The charging overcurrent will be explained. When the alternator 10B of the motorcycle breaks down, charging overcurrent may flow to the secondary battery 62 . The management unit 130 detects the current value and direction of the current flowing through the secondary battery 62 with the current sensor 53 at predetermined time intervals, and determines whether the current direction is the charging direction or the discharging direction. If the current is in the charging direction, the management unit 130 determines whether the current value is equal to or higher than a predetermined value. 4).

Discharge overcurrent will be explained. If there is a resistor 160 externally short-circuiting the positive electrode external terminal 51 and the negative electrode external terminal 52 of the battery 50 , a discharge overcurrent flows through the secondary battery 62 . As described above, the management unit 130 detects the current value and direction of the current flowing through the secondary battery 62 by the current sensor 53 at predetermined time intervals, and determines whether the current direction is the charging direction or the discharging direction. . If the current is in the discharge direction, the management unit 130 determines whether or not the current value is equal to or higher than a predetermined value. 5).

(4-3) FET-on processing FET-on processing is when the circuit breaker 55 (charging FET 55A or discharging FET 55B) is turned off by the secondary battery protection processing described above, and then the secondary battery 62 is used again. This processing is to turn on the circuit breaker 55 according to the detection result of the detector 140 (the first detection circuit 141 or the second detection circuit 142). A specific description will be given below.

(4-4-1) When Overcharging is Predicted and the Charging FET is Turned Off After the management section 130 predicts overcharging and turns off the charging FET 55A, the alternator 10B charges the secondary battery 62. The first detection circuit 141 detects whether or not the battery is in the charging state at regular time intervals. example).

(4-4-2) When overdischarge is predicted and the discharge FET is turned off After the management unit 130 predicts overdischarge and turns off the discharge FET 55B, the alternator 10B charges the secondary battery 62. The first detection circuit 141 detects whether or not the battery is in the charging state at regular time intervals, and turns on the discharging FET 55B when it detects that the battery is in the charging state (first ON processing, third ON processing). example).

When overdischarge is foreseen, the discharge FET 55B is turned off, but the charge FET 55A is kept on. Therefore, when overdischarge is foreseen and the discharge FET 55B is turned off, the management unit 130 detects the direction of the current with the current sensor 53 at predetermined time intervals. 10B may be determined to be in a state of charging the secondary battery 62 .

(4-4-3) When charging overcurrent is detected and the charging FET is turned off The management unit 130 detects the charging overcurrent and turns off the charging FET 55A. is detected at regular time intervals by the first detection circuit 141, and when it is detected that the battery is not charged, the charging FET 55A is turned on (first ON processing, fourth an example of ON processing).

(4-4-4) When the discharge overcurrent is detected and the discharge FET is turned off The management unit 130 detects the discharge overcurrent and turns off the discharge FET 55B, and then determines whether the resistor 160 exists. is detected at regular time intervals by the second detection circuit 142, and when the absence of the resistor 160 is detected, the discharge FET 55B is turned on (an example of the fifth ON process).

(5) Effects of the Embodiment According to the battery 50, even if the battery 50 does not have the function of communicating with the ECU of the motorcycle 10, after the abnormality of the secondary battery 62 is detected and the circuit breaker 55 is turned off, the secondary The circuit breaker 55 can be turned on while reducing the possibility that the battery 62 will fall into an abnormal state again.

According to the battery 50, since the first detection circuit 141 is a resistance voltage dividing circuit, the first detection circuit 141 can be realized with a simple configuration.

According to the battery 50, when overcharging of the secondary battery 62 is foreseen and the charging FET 55A is turned off, the charging FET 55A is turned on when the alternator 10B does not charge the secondary battery 62 after that. The charging FET 55A can be turned on while reducing the possibility that the secondary battery 62 will be overcharged.

According to the battery 50, when overdischarge of the secondary battery 62 is foreseen and the discharging FET 55B is turned off, the discharging FET 55B is turned on when the alternator 10B is in a state of charging the secondary battery 62 after that. The discharge FET 55B can be turned on while reducing the possibility that the secondary battery 62 will be over-discharged.

According to the battery 50, when charging overcurrent is detected and the charging FET 55A is turned off, the charging FET 55A is turned on when the alternator 10B is not charging the secondary battery 62, so that the secondary battery 62 is charged again. The charging FET 55A can be turned on while reducing the possibility of charging overcurrent.

According to the battery 50, after the discharge overcurrent is detected and the discharge FET 55B is turned off, the second detection circuit 142 detects that there is no resistor 160 externally short-circuiting the positive electrode external terminal 51 and the negative electrode external terminal 52. is detected, the discharge FET 55B is turned on. Therefore, in the battery 50 for a motorcycle, after the discharge overcurrent of the secondary battery 62 is detected and the discharge FET 55B is turned off, the discharge FET 55B is turned off while reducing the possibility that the secondary battery 62 is again short-circuited to the outside. can be turned on.

According to the battery 50, the second detection circuit 142 is a resistive voltage dividing circuit, so the second detection circuit 142 can be realized with a simple configuration.

<Other embodiments>
The technology disclosed in this specification is not limited to the embodiments described in the above description and drawings, and the following embodiments are also included in the technical scope disclosed in this specification.

(1) In the above embodiment, the first detection circuit 141 is exemplified by a resistance voltage dividing circuit. can be detected, and is not limited to a resistive voltage dividing circuit. The same applies to the second detection circuit 142, and it is not limited to a resistance voltage dividing circuit as long as it can detect the presence or absence of the resistor 160 externally short-circuiting the positive electrode external terminal 51 and the negative electrode external terminal 52 of the battery 50. .

(2) In the above embodiment, the first detection circuit 141 includes two resistance voltage dividing circuits (a resistance voltage dividing circuit consisting of resistors R1 and R2, and a resistance voltage dividing circuit consisting of resistors R3, R4 and R5). ), the first detection circuit 141 may be one using only one resistance voltage dividing circuit, or a combination of three or more resistance voltage dividing circuits. There may be. The same is true for the second detection circuit.

(3) In the above embodiment, the circuit breaker 55 is FET as an example, but the circuit breaker 55 may be a relay.

(4) In the above embodiment, the battery 50 for a two-wheeled vehicle has been described as an example of a power storage device that does not have a function of communicating with an external device. However, even if the battery is for a four-wheeled vehicle, the power storage device may be a battery for a four-wheeled vehicle if it does not have a function of communicating with an external device.

(5) In the above embodiments, a lithium ion battery was used as an example of a power storage element, but the power storage element is not limited to this. For example, the storage element may be a capacitor that involves an electrochemical reaction.

10 motorcycle 10B alternator (an example of an external charger)
50 Battery (an example of a power storage device)
51 positive electrode external terminal 52 negative electrode external terminal 55 circuit breaker 62 secondary battery (an example of an electric storage element)
130 Management unit 141 First detection circuit 142 Second detection circuit 160 Resistor

Claims (6)

A power storage device that does not have a function of communicating with an external device,
a storage element;
a circuit breaker connected in series with the storage element;
a first detection circuit that detects whether or not an external charger is in a state of charging the storage element when the circuit breaker is off;
A second detection circuit connected in parallel with the first detection circuit for detecting the presence or absence of a resistor externally short-circuiting the positive electrode external terminal and the negative electrode external terminal of the power storage device when the circuit breaker is off. a detection circuit;
management department and
with
The management department
a first protection process of turning off the circuit breaker to protect the storage element from an abnormality when an abnormality of the storage element is detected;
a first ON process for turning ON the circuit breaker according to a detection result of the first detection circuit after turning OFF the circuit breaker by the first protection process;
and run
The first protection process includes a fifth protection process of turning off the circuit breaker to protect the storage element from overcurrent when an overcurrent in the discharge direction is detected,
The management department
After turning off the circuit breaker by the fifth protection process, executing a fifth turn-on process of turning on the circuit breaker when the second detection circuit detects that the resistor is absent; storage device. The power storage device according to claim 1,
the first detection circuit is a resistance voltage dividing circuit provided in parallel with the storage element and the circuit breaker;
The power storage device, wherein the second detection circuit is a resistance voltage dividing circuit provided in parallel with the power storage element and the circuit breaker . The power storage device according to claim 1 or claim 2,
The first protection process includes a second protection process of turning off the circuit breaker when overcharging of the power storage element is foreseen,
In the first ON process, after the circuit breaker is turned off by the second protection process, the first detection circuit detects that the external charger does not charge the storage element. a power storage device including a second ON process for turning on the circuit breaker when the electric storage device is turned on. The power storage device according to any one of claims 1 to 3,
The first protection process includes a third protection process of turning off the circuit breaker when overdischarge of the storage element is foreseen,
In the first ON process, after the circuit breaker is turned off by the third protection process, the first detection circuit detects that the external charger is charging the storage element. a power storage device including a third ON process for turning on the circuit breaker when the electric storage device is turned on. The power storage device according to any one of claims 1 to 4,
The first protection process includes a fourth protection process of turning off the circuit breaker when an overcurrent in the charging direction is detected,
In the first ON process, after the circuit breaker is turned off by the fourth protection process, the first detection circuit detects that the external charger does not charge the storage element. a fourth ON process for turning on the circuit breaker when the power storage device is turned on. The power storage device according to claim 2,
One end of the first detection circuit and the second detection circuit is connected to a positive power line between the storage element and the positive electrode external terminal, and the other end is connected between the storage element and the negative electrode external terminal. provided on a first signal line connected to the negative power line between
A power storage device in which a signal line branching from between the voltage dividing resistors of the first detection circuit and a signal line branching from between the voltage dividing resistors of the second detection circuit are connected to the same voltage sensor. .

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