TWI688182B - Battery pack, battery system and discharge method - Google Patents

Abstract

The internal current of the battery pack is appropriately discharged, and the maintainability is improved. The battery system includes a plurality of battery packs 200 and a second IC18. The plurality of battery packs 200 includes: a lithium-ion battery 16; a main circuit that is connected in series with the lithium-ion battery 16 and becomes a power supply path; and a second protection circuit 62, which is connected in parallel with the lithium ion battery 16, and consumes internal power under certain conditions; and a switching mechanism, which blocks the lithium ion battery 16 from the main circuit, and connects the lithium ion battery 16 and the second protection circuit 62; The second IC18 is connected to the main circuit and the second protection circuit of each battery pack 200, and controls the input and output from each battery pack 200; the second IC18 detects the output from any protection circuit of the battery pack 200 In the case of current or voltage, an abnormality of the battery pack is reported.

Description

Battery pack, battery system and discharge method

The present invention relates to a battery pack and a battery system including a plurality of battery packs, and particularly relates to a battery pack, a battery system, and a discharge method that can appropriately discharge a residual current from inside the battery pack. This application claims priority based on Japanese Patent Application No. Japanese Patent Application No. 2014-099714 filed in Japan on May 13, 2014, and these applications are incorporated into this application by reference.

Most secondary batteries that can be used repeatedly after being charged are processed into battery packs and provided to users. Especially for lithium ion secondary batteries with high weight energy density, in order to ensure the safety of users and electronic equipment, several protection circuits such as overcharge protection and overdischarge protection are generally built into the battery pack. The function of blocking the output of the battery pack in the case.

In such protection elements, there are already FET (Field Effect Transistor) switches built in the battery pack to output or stop the output, thereby performing overcharge protection or overdischarge protection for the battery pack By. However, in the case where the FET switch is short-circuited and damaged due to some reasons, when a momentary large current flows due to the application of a lightning surge, etc., or the output voltage is abnormally reduced due to the life of the battery cell , Or vice versa, the battery pack or electronic equipment must be protected from accidents such as fire. Therefore, in order to safely block the output of the single cell in any abnormal state conceivable as described above, a protection element composed of a fuse element is used, which has a External signal to block the current path.

As a protection circuit for lithium ion secondary batteries etc. as mentioned above As disclosed in Patent Document 1, there is already a protective element that connects the first electrode over the current path, the conductor layer connected to the heating element, and the fusible conductor between the second electrodes to form a current path A part of the fusible conductor on the current path is fused by self-heating caused by overcurrent or a heating element provided inside the protection element. In such a protective element, the meltable liquid soluble conductor is concentrated on the conductor layer connected to the heating element, thereby blocking the current path.

In addition, for the LED lighting device, the following structure has been proposed: It is connected in parallel to each LED (Light Emitting Diode) element connected in series. When the LED is abnormal, the short-circuit element is short-circuited due to a specific voltage, causing the normal LED to emit light (Patent Document 2). The short-circuit element disclosed in Patent Document 2 is connected in series with a plurality of elements composed of an insulating barrier layer sandwiched by a metal with a specific film thickness.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2006-109596

[Patent Document 2] Japanese Patent Application Publication No. 2007-012381

In recent years, EVs (Electric Vehicles) or HEVs (Hybrid Electric Vehicles) using batteries and motors have rapidly spread. Considering the energy density and output characteristics, lithium ion secondary batteries are gradually used as the power source for HEV or EV. Yu Qiaoying For use, high voltage and high current are required. Therefore, dedicated battery cells that can withstand high voltages and large currents have been developed. However, due to manufacturing cost issues, in most cases, a plurality of battery cells are connected in series or parallel, thereby using universal battery cells to ensure Necessary voltage and current.

Furthermore, a module formed by connecting a plurality of single cells in series is set as a battery pack, and A plurality of the above battery packs are arranged in series to form a battery system, and parts can be replaced in units of battery packs, thereby improving maintainability.

However, in the battery system described above, when one battery pack fails, the battery packs are arranged in parallel, so the output voltage does not decrease, but the output current decreases. Even if it is possible to detect a battery failure based on a decrease in output current, it is impossible to determine which battery pack has a failure, which is a main cause that hinders the improvement of maintainability.

The present invention is an invention that solves the above problems, and aims to provide a battery pack, a battery system, and a discharge method that use a battery pack protection circuit to report an abnormality of the battery pack, thereby ensuring the safety of the battery system and improving the maintainability.

In order to solve the above problems, the battery pack of the present invention includes: a secondary battery; a main circuit connected in series with the secondary battery and serving as a charge/discharge path for the secondary battery; and a protection circuit connected in parallel with the secondary battery, And consume the power of the secondary battery under certain conditions; the switching mechanism, which blocks the secondary battery and the main circuit and connects the secondary battery and the protection circuit under certain conditions; and the error signal output mechanism, which will send to the protection circuit The output current is output to the outside as an error signal.

Furthermore, the battery system of the present invention includes a plurality of battery packs and a control mechanism. The plurality of battery packs includes: a secondary battery; a main circuit, which is connected in series with the secondary battery, and becomes It is a power supply path; a protection circuit that is connected in parallel with the secondary battery and consumes internal power under certain conditions; and a switching mechanism that blocks the secondary battery and the main circuit and connects the secondary battery and the protection circuit; The control mechanism is connected to the main circuit and the protection circuit of each battery pack, and controls the input and output from each battery pack; the control mechanism determines the battery pack when it detects the current output from any of the above protection circuits of each battery pack mistake.

In addition, the discharge method of the present invention is a discharge method of a battery pack. A main circuit connected to the secondary battery in series and serving as a power supply path is connected to the above secondary battery, and a protection circuit and a secondary battery connected in parallel to the secondary battery and consuming internal power under certain conditions are connected by the protection circuit Internal discharge is performed, and at least a part of the output current output to the protection circuit is output as an error signal to the outside of the battery pack.

According to the present invention, when an abnormality of the battery pack is detected, it can be switched to the protection circuit, and the current flowing to the protection circuit of the battery pack can be output as an error signal, and the battery pack and the battery system can be easily notified according to the error signal Error, and determine the battery pack that outputs the error signal, which can improve the maintainability of the battery pack.

11‧‧‧Negative terminal

12‧‧‧Positive terminal

13‧‧‧The first FET

14‧‧‧ 2nd FET

15‧‧‧ First IC

16‧‧‧Lithium ion battery

17‧‧‧Switching element

18‧‧‧ 2nd IC

19‧‧‧External terminal

20‧‧‧LED

21‧‧‧Heating resistor

22‧‧‧Overheat detection sensor

23‧‧‧Collision sensor

31‧‧‧Heating resistor

32‧‧‧Fusable conductor

33‧‧‧ switch

41‧‧‧current control element

51‧‧‧Ground terminal

52‧‧‧Control terminal

53‧‧‧Control terminal

61‧‧‧The first protection circuit

62‧‧‧The second protection circuit

100‧‧‧ battery system

200‧‧‧ battery pack

300‧‧‧Control unit

400‧‧‧Notification Department

FIG. 1 is a block diagram illustrating a battery system.

FIG. 2 is a block diagram illustrating the structure of the battery pack.

FIG. 3 is a block diagram illustrating the structure of the battery pack.

FIG. 4 is a circuit diagram illustrating the operation of the switching element.

FIG. 5 is a circuit diagram illustrating the operation of the battery pack.

6 is a circuit diagram illustrating the operation of the battery pack.

7 is a circuit diagram illustrating the operation of the battery pack.

Hereinafter, the battery pack, battery system, and discharge method to which the present invention is applied will be described in detail while referring to the drawings. Furthermore, the present invention is not limited to the following embodiments, and of course various changes can be made without departing from the scope of the present invention. In addition, the diagram is a model diagram, and the ratio of each dimension may be different from reality. The specific dimensions should be judged in consideration of the following description. In addition, the drawings also naturally include parts having different dimensional relationships or ratios.

[Battery System]

Hereinafter, a battery system in which a plurality of lithium ion battery modules for EVs and the like are arranged in parallel will be described as an example.

As shown in FIG. 1, the battery system 100 includes a plurality of battery packs 200, a control unit 300 connected to the battery pack 200 and controlling charge and discharge of each battery pack 200, and shown and reported that an error signal described later has been output The notification unit 400 of the battery pack 200 is configured.

The details of each battery pack 200 will be described later. Each battery pack 200 is a module in which a lithium-ion battery and a protection circuit are modularized. It can output an error signal to the control unit 300 when the battery is abnormal and can consume internal current. Way composition.

The control unit 300 is composed of an IC circuit or the like, controls the charging of each battery pack 200 or the power supply from each battery pack 200, and controls the supply of current to an EV, such as a motor or various electrical components. In addition, the control unit 300 detects the abnormality of the battery pack 200 that emits the error signal based on the error signal from the battery pack 200 described later, and uses the notification section 400 An abnormality of the battery pack 200 is reported.

The notification unit 400 is connected to the control unit 300, and is composed of a light emitting mechanism or a sound mechanism The structure reports an abnormality of the battery pack 200 by emitting light or sound. The specific configuration of the notification unit 400 is substantially the same as the notification mechanism provided in the battery pack 200 described later, and therefore the description is omitted.

[Battery]

As shown in FIG. 2, the battery pack 200 has input and output terminals, that is, a negative terminal 11 and a positive terminal 12, a first FET (Field Effect Transistor) 13 and a second FET 14, and controls the first FET 13 and the second FET 14 The first IC (Integrated Circuit) 15, the lithium ion battery 16, the switching element 17 for switching the main circuit and the protection circuit, the second IC 18 for controlling the switching element 17, the external output terminal 19, the LED (Light Emitting Diode (Light Emitting Diode) 20 and heating resistor 21.

The negative terminal 11 and the positive terminal 12 and the control unit 300 of the battery system 100 The connection forms a main circuit (first circuit) for charging and discharging the lithium ion battery 16. In addition, the negative electrode terminal 11 and the positive electrode terminal 12 together with the external output terminal 19 become an interface to be connected to the control unit 300 via a connector or the like.

The first FET 13 and the second FET 14 are connected in series with the lithium ion battery 16 Transistor components placed on the main circuit. The first IC15 is connected to the first FET13 and the second FET14, and the first FET13, the second FET14, and the first IC15 form a first protection circuit.

The first IC15 of the first protection circuit and the overheat detection sensor (not shown), etc. Connect to determine whether the internal temperature of the battery pack 200 is above a specific value. When determining the internal temperature of the battery pack 200 is above a specific value, in order to protect the overheated lithium ion battery 16, drive the first FET 13 or the second The FET14 blocks the main circuit.

In addition, the first IC15 of the first protection circuit and the current monitor (not shown), etc. Connect to determine whether the current value of the main circuit is above a specific value. When determining that the current value of the main circuit is above a specific value, it is in an overcurrent state. In order to protect the lithium ion battery 16, the first FET 13 or the second FET14 blocks the main circuit.

Lithium ion battery 16 is a series of multiple single cells arranged in series to achieve The desired voltage value is constructed. Here, the lithium-ion battery 16 has a higher energy density and a higher electromotive force than a lead-acid battery or a nickel-metal hydride battery. Therefore, it is suitable for use in EVs and the like.

The switching element 17 is arranged on the main circuit in series with the lithium-ion battery 16, the second The IC 18 is connected to the switching element 17. Here, the switching element 17 constitutes a switching mechanism that switches the main circuit and the second protection circuit.

Here, the second protection circuit is a bypass circuit, which is connected in parallel with the lithium ion battery 16 Ground arrangement, one end is connected to the switching element 17, and the other end is connected between the second FET 14 and the lithium ion battery 16. In the second protection circuit, an external output terminal 19, an LED (Light Emitting Diode) 20, and a heating resistor 21 are arranged in series in this order. Furthermore, the arrangement order of these components is not particularly limited, but the external output terminal 19 is arranged near the switching element 17.

The external output terminal 19 is a terminal connected to the outside of the battery pack 200 At least a part of the current that the external output has output to the second protection circuit serves as an error signal. Specifically, the external output terminal 19 is connected to the control unit 300 of the battery system 100 and functions as one of the notification mechanisms for reporting the error of the battery pack 200 to the battery system 100.

The LED 20 is provided in an external portion (not shown) of the battery pack 200, and serves as a current The light-emitting mechanism that emits light when flowing to the second protection circuit functions. Specifically, the LED 20 functions as a notification mechanism for reporting the abnormality of the battery pack 200 to the outside. Furthermore, it can also Various other lamps are used as light-emitting mechanisms, but LEDs that operate with low power and cost less than other light-emitting mechanisms are particularly preferred.

Also, LED20 is also part of the discharge mechanism in the second protection circuit Function. That is, since power is consumed by light emission, the internal current of the battery pack 200 can be consumed, and the remaining power in the battery pack 200 can be consumed to protect the lithium ion battery 16.

The heating resistor 21 consumes electricity flowing to the second protection circuit by heating It functions as part of the discharge mechanism. The heating resistor 21 can consume the internal current of the battery pack 200 and can consume the surplus power in the battery pack 200 to protect the lithium ion battery 16.

Here, the external output terminal 19, the LED 20, and the heating resistor 21 are connected in series It is arranged on the second protection circuit connected in parallel with the lithium-ion battery 16, but the order of these components can be changed appropriately, or can be arranged on the second protection circuit in parallel, respectively, in order to maintain the report of the error of the battery pack 200. Of course, within the range of the function and the discharge function that consumes the surplus power in the battery pack 200, of course, the configuration can be appropriately changed.

Next, the switching of the second IC18 for the circuit will be described. As shown in Figure 3, electricity The pool group 200 is connected to the overheat detection sensor 22 and the collision sensor 23. The second IC 18 is connected to the overheat detection sensor 22 and the collision sensor 23, respectively.

For the overheat detection sensor 22, for example, PTC (Positive Temperature) can be used Coefficient, positive temperature coefficient) thermistor, etc. In addition, the overheat detection sensor 22 is preferably built in each battery pack 200 to detect overheating in the battery pack 200, but the structure of the battery system 100 outside the battery pack 200 is further described.

For the collision sensor 23, for example, an acceleration sensor or the like can be used. Use acceleration In the case of a high-speed sensor, when the acceleration of the battery pack 200 exceeds a certain value, it can detect An accident such as a collision occurred in the EV. In addition, the collision sensor 23 is preferably built in the battery pack 200 to detect the collision in the battery pack 200, but it can also be configured as a battery system 100 outside the battery pack 200.

In addition, it can be incorporated into a part of the entire EV, or can be controlled by the control unit 300 If a central control unit such as an ECU (Engine Control Unit), not shown, obtains a CAN (Controller Area Network) signal, the control unit 300 outputs the obtained CAN signal to each battery pack 200 The acceleration information can thereby reduce the number of sensors in the entire EV.

The second IC18 judges the inside of the battery pack 200 by detecting the sensor 22 overheating Whether the temperature of is above a certain value, when it is judged to be above a certain value, it is in an overheated state, and in order to protect the lithium ion battery 16, the switching element 17 is controlled to block the main circuit and switch to the second protection circuit.

In addition, the second IC 18 uses the collision sensor 23 to determine whether the battery pack 200 is In a specific collision, for example, when it is determined that the acceleration is above a specific value, the switching element 17 is controlled to block the main circuit and switch to the second protection circuit in order to protect the lithium ion battery 16 in an accident or other unexpected state.

In addition, the second IC18 and the heating detection sensor are described in the above 22 is connected to the collision sensor 23 to obtain information from these sensors, but it can also be connected to other sensors and the like to input the information required to protect the battery pack 200. At least one sensor information is input to the second IC18. Furthermore, it does not hinder the configuration in which the second IC 18 regularly controls the switching element 17 by the timer logic circuit.

In addition, although the first IC15 and the second IC18 are described separately, One IC. In the case of one IC, the number of parts can be reduced. On the other hand, when divided into individual ICs, the first protection circuit and the second protection circuit can be operated independently, and can have the repeatability of the protection function, thereby becoming a safer battery pack.

[Switching element]

The switching element 17 will be specifically described. As shown in FIGS. 2 and 4, the switching element 17 is a four-terminal element composed of a first terminal a, a second terminal b, a third terminal c, and a fourth terminal d. The switching element 17 is planarly mounted on an insulating substrate (not shown), and has a heating resistor 31, a fusible conductor 32, and a switch 33.

The first terminal a of the switching element 17 is connected to the positive electrode of the lithium ion battery 16, the second terminal b is connected to the positive terminal 12 of the battery pack 200, the third terminal c is connected to the second IC 18, and the fourth terminal d is connected to the protection circuit .

Inside the switching element 17, one end of the heating resistor 31, one end of the soluble conductor 32 and one end of the switch 33 are connected to the first terminal a, and the other end of the soluble conductor 32 is connected to the second terminal b. In the switching element 17, the other end of the heating resistor 31 is connected to the third terminal c, and the other end of the switch 33 is connected to the fourth terminal d.

[Switching element circuit]

The switching element 17 has a circuit configuration as shown in FIGS. 4(A)(B). That is, the first terminal a and the second terminal b of the switching element 17 are connected when they are normal, that is, the first terminal a and the third terminal d are insulated when they are normal.

The switching element 17 constitutes a switch 33 which is short-circuited by the molten conductor when the fusible conductor 32 is melted due to heat generated by the heating resistor 31 (FIG. 4(B) ). In addition, the first terminal a and the fourth terminal d constitute two terminals of the switch 33. In addition, the fusible conductor 32 is connected to the second electrode b.

Furthermore, as described above, the switching element 17 is incorporated in the battery pack 200, whereby the first terminal a and the fourth terminal d on both sides of the switch 33 are connected in parallel with the main circuit of the battery pack 200, and the battery pack 200 When an abnormality occurs, the switch 33 is short-circuited to form a bypass current path (second protection circuit) that bypasses the battery pack 200.

Specifically, if an abnormality occurs in the lithium ion battery 16 or other electronic components connected in parallel, the switching element 17 supplies power from the third terminal c side of the heating resistor 31, and the heating resistor 31 generates heat by being energized. When the fusible conductor 32 melts due to this heat, as shown in FIG. 4(B), the molten conductor condenses on the switch 33. As a result, the first electrode a and the fourth electrode d are short-circuited. That is, the switching element 17 short-circuits the two terminals of the switch 33 (FIG. 4(B)).

Furthermore, when the heating resistor 31 is energized, the main circuit is blocked by the fusible conductor 32 and the current flows to the second protection circuit. Therefore, it is preferable to stop supply of current from the third terminal c when this situation is detected. . Furthermore, this control can be controlled by the second IC18.

The current output to the second protection circuit by the switching element 17 is output as an error signal to be described later to the outside of the battery pack 200, and is used as a trigger signal for reporting an abnormality of the battery pack 200.

In addition, the switching element 17 is not limited to the structure described above, and can be appropriately configured to selectively switch the main circuit and the second protection circuit. For example, a method of using the two FETs described in the first protection circuit can also be used.

[Battery pack circuit configuration]

Next, the circuit configuration of the battery pack 200 incorporating the switching element 17 will be described. The circuit configuration of the battery pack 200 with the built-in lithium-ion battery 16 is shown in FIG. 5 and includes a lithium-ion battery 16, a first IC15 that controls the operation of the first FET13 and the second FET14, and a short-circuit element 17. The current control element 41 and the second IC 18 that control the operation of the short-circuit element 17, the LED 20 and the heating resistor 21 on the protection circuit, via the positive terminal 12, the negative terminal 11, the ground terminal 51 of the battery pack 200, control The terminals 52 and 53 and the external terminal 19 are connected to the control unit 300.

Here, the battery pack 200 includes: a first protection circuit 61 that controls the charging and discharging of the lithium ion battery 16; a detection circuit that detects the voltage of the lithium ion battery 16 and outputs an abnormal signal to control the operation of the switching element 17 The current control element 41; and the second protection circuit 62, which is connected to the lithium ion battery 16 through the switching element 17.

The first protection circuit 61 is composed of the first FET 13 and the second FET 14 and the first IC 15. The first FET 13 and the second FET 14 are connected in series to the current path flowing from the control unit 300 to the lithium ion battery 16. The first IC 15 controls the operation of the first FET 13 and the second FET 14.

The switching element 17 of the battery pack 200 is connected in series with the lithium ion battery 16, the second terminal b of the switching element 17 is connected to the charge and discharge path of the lithium ion battery 16, and the first terminal a is connected to the positive electrode of the lithium ion battery 16, thereby forming The main circuit. In addition, the heating resistor 31 of the switching element 17 of the battery pack 200 is connected to the current control element 41 via the third terminal c.

The first IC15 of the first protection circuit 61 is connected to the lithium ion battery 16 via the second IC18, and the voltage value of each single cell is detected. When the lithium ion battery 16 reaches the overcharge voltage or the overdischarge voltage, the first IC15 outputs an abnormal signal to the first FET13 and the second FET14. In addition, the first IC 15 can also be a circuit configuration that directly detects the voltage value of the lithium ion battery 16.

The current control element 41 is, for example, an FET, and is a switching element as follows, which is based on The detection signal output from the second IC 18 operates to cause the current to flow to the heating resistor 31 when the voltage value of the lithium ion battery 16 exceeds a specific voltage in the overdischarge or overcharge state. The current control element 41 causes current to flow to the heating resistor 31 to fuse the fusible conductor 32, and operates the switching element 17 to turn on the switch 33 to block the lithium ion battery 16 from the main circuit and connect the second protection circuit.

The current control element 41 can be controlled as follows according to the control from the second IC18 Control, that is, the charging and discharging current path of the lithium-ion battery 16 is blocked regardless of the switching operation of the first FET 13 and the second FET 14, and the switch 33 of the switching element 17 is short-circuited, bypassing the main circuit to form the first 2保护电路62.

As described above, when the battery pack 200 is normal, as shown in FIG. 5, the switch 33 of the switching element 17 is not short-circuited. Therefore, the current flows to the lithium ion battery 16 side through the fusible conductor 32.

When it is detected that the voltage of the lithium ion battery 16 is abnormal, etc., the second IC 18 outputs an abnormal signal to the current control element 41, and the third terminal c of the switching element 17 is connected to the ground. As a result, as shown in FIG. 6, current flows to the heating resistor 31 of the switching element 17, and the heating resistor 31 generates heat.

Next, as shown in FIG. 7, the switching element 17 heats the fusible conductor 32 by the heating resistor 31 to melt it, thereby blocking the first terminal a and the second terminal b. As a result, as shown in FIG. 7, the lithium ion battery 16 having an abnormal single cell can be blocked from the charging and discharging current path as the main circuit. Furthermore, after the fusible conductor 32 is blown, the current control element 41 is actuated by the control of the second IC 18 without flowing a current, thereby stopping power supply to the heating resistor 31.

Next, in the battery pack 200, the switch 33 of the switching element 17 is connected, and the lithium The current of the ion battery 16 flows to the second protection circuit 62. As a result, the LED 20 of the second protection circuit 62 is lit, so that the abnormality of the battery pack 200 can be reported, and the internal current can be discharged through the heating resistor 21.

Here, in the battery pack 200, the external terminal 19 is connected to the second protection circuit 62. At least a part of the current flowing to the second protection circuit 62 is output to the control unit 300 as an error signal. The control unit 300 stops the charging of the battery pack 200 that has received the error signal, and reports the abnormality of the battery pack 200 through the notification unit 400.

Furthermore, the control unit 300 can monitor the error signal according to the current value, The voltage value can be monitored. That is, the current value of the current output from the external terminal 19 can be monitored, and the voltage value between the negative terminal 11 and the external terminal 19 can also be monitored. If the monitored current value or voltage value is above a certain value, the control unit 300 determines that an error signal has been received. In addition, it is preferable to appropriately set the specific value to a value that removes noise and the like.

A battery system 100 having a plurality of battery packs 200 as described above, even if When an abnormal situation occurs in a battery pack 200, the battery pack 200 can also be charged and discharged by using the remaining normal battery pack 200 to maintain the function.

As described above, in the battery system 100 of the example of the present invention, the battery pack 200 When a certain condition is satisfied, an internal current is released and an error signal is sent to the outside to report an error. Therefore, it is possible to individually detect abnormality of each battery pack 200, and it is possible to improve maintenance performance such as failure replacement of the battery pack 200.

In addition, in the battery system 100 of the example of the present invention, The LED 20 visually confirms the faulty battery pack 200, and also outputs an error signal from each battery pack 200, therefore, it is easy to determine the faulty location. As a result, many batteries are installed like EV For the device 200 and the battery device 200 that needs to be replaced, a particularly significant effect can be obtained.

11‧‧‧Negative terminal

12‧‧‧Positive terminal

13‧‧‧The first FET

14‧‧‧ 2nd FET

15‧‧‧ First IC

16‧‧‧Lithium ion battery

17‧‧‧Switching element

18‧‧‧ 2nd IC

19‧‧‧External terminal

20‧‧‧LED

21‧‧‧Heating resistor

200‧‧‧ battery pack

a‧‧‧First terminal

b‧‧‧2nd terminal

c‧‧‧3rd terminal

d‧‧‧4th terminal

Claims (23)

A battery pack comprising: a secondary battery; a main circuit connected in series with the secondary battery and serving as a charge and discharge path for the secondary battery; a protection circuit connected in parallel with the secondary battery and Under certain conditions, the power of the secondary battery is consumed; a switching mechanism that blocks the secondary battery and the main circuit and connects the secondary battery and the protection circuit under the specific conditions; and an error signal output mechanism, which The output current output to the above protection circuit is output as an error signal to the outside. A battery pack as claimed in item 1 of the patent application, wherein the protection circuit is further provided with an external terminal; the current or voltage on the protection circuit is output as an error signal to the outside through the external terminal. For example, in the battery pack of claim 1 or 2, the above protection circuit is further provided with a light emitting mechanism; an error is reported by causing the light emitting mechanism to emit light. For example, in the battery pack of claim 1 or 2, the sound protection mechanism is further provided on the protection circuit; an error is reported by the sound output of the sound protection mechanism. For example, the battery pack of claim 3, in which Further, a sound mechanism is provided on the protection circuit; an error is reported by the sound output of the sound mechanism. For example, the battery pack of patent application item 1 or 2 further includes an overheat detection sensor for detecting temperature rise; the switching mechanism blocks the secondary battery based on the detection information of the overheat detection sensor The battery is connected to the main circuit, and the secondary battery is connected to the protection circuit. For example, the battery pack of claim 3 of the patent scope further includes an overheat detection sensor for detecting temperature rise; the switching mechanism blocks the secondary battery and the secondary battery based on the detection information of the overheat detection sensor The main circuit is connected to the secondary battery and the protection circuit. For example, the battery pack of claim 4 of the patent scope further includes an overheat detection sensor for detecting temperature rise; the switching mechanism blocks the secondary battery and the secondary battery based on the detection information of the overheat detection sensor The main circuit is connected to the secondary battery and the protection circuit. A battery pack as claimed in item 5 of the patent scope further includes an overheat detection sensor for detecting temperature rise; the switching mechanism blocks the secondary battery and the secondary battery based on the detection information of the overheat detection sensor The main circuit is connected to the secondary battery and the protection circuit. The battery pack as claimed in item 1 or 2 of the patent scope further includes a collision sensor for detecting collision; the switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor , And connect the secondary battery and the protection circuit. A battery pack as claimed in item 3 of the patent scope further includes a collision sensor for detecting collision; the switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor, and Connect the secondary battery and the protection circuit. A battery pack as claimed in item 4 of the patent scope further includes a collision sensor for detecting collision; the switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor, and Connect the secondary battery and the protection circuit. The battery pack as claimed in item 5 of the patent scope further includes a collision sensor for detecting collision; the switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor, and Connect the secondary battery and the protection circuit. A battery pack as claimed in item 6 of the patent scope, further comprising a collision sensor for detecting collision; the switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor, and Connect the secondary battery and the protection circuit. A battery pack as claimed in item 7 of the patent scope, further comprising a collision sensor for detecting collision; the switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor, and Connect the secondary battery and the protection circuit. For example, the battery pack of claim 8 of the patent scope, which further includes a collision sensor for detecting collision; The switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor, and connects the secondary battery and the protection circuit. A battery pack as claimed in item 9 of the patent scope, which further includes a collision sensor for detecting collision; the switching mechanism blocks the secondary battery and the main circuit based on the detection information of the collision sensor, and Connect the secondary battery and the protection circuit. A battery system including a plurality of battery packs and a control mechanism, the plurality of battery packs having: a secondary battery; a main circuit connected in series with the secondary battery and serving as a power supply path; and a protection circuit The secondary batteries are connected in parallel and consume internal power under certain conditions; and a switching mechanism that blocks the secondary battery and the main circuit and connects the secondary battery and the protection circuit; the control mechanism and the batteries The main circuit and the protection circuit of the group are respectively connected and control the input and output from the battery packs; when the control mechanism detects the current or voltage output from any of the protection circuits of the battery packs, Judge the error of the above battery pack. As in the battery system of claim 18, the control mechanism stops supplying power to the battery pack that has been judged wrong. For example, the battery system of claim 18 or 19, which further includes a light-emitting mechanism; The error is reported by making the light-emitting mechanism emit light. For example, the battery system of claim 18 or 19, which further includes a sound mechanism; an error is reported by the sound output of the sound mechanism. For example, the battery system of patent application scope item 20 further includes a sound mechanism; an error is reported by the sound output of the sound mechanism. A discharge method which is a discharge method of a battery pack; blocking a main circuit connected in series with a secondary battery and serving as a power supply path to the secondary battery; connecting a parallel connection with the secondary battery and consuming under certain conditions The internal power protection circuit and the secondary battery are internally discharged by the protection circuit, and at least a part of the output current output to the protection circuit is output as an error signal to the outside of the battery pack.

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