CN113049970A

CN113049970A - Battery protection plate, battery and detection method

Info

Publication number: CN113049970A
Application number: CN202110298508.4A
Authority: CN
Inventors: 蒋耀; 卓加杰
Original assignee: Dongguan Nvt Technology Co Ltd
Current assignee: Dongguan Nvt Technology Co Ltd
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2021-06-29
Anticipated expiration: 2041-03-19
Also published as: CN113049970B

Abstract

The application discloses a battery protection board, a battery and a detection method. The battery protection board comprises a battery cell positive electrode connecting end, a battery cell negative electrode connecting end, a host machine positive connecting end, a host machine negative connecting end, a first overvoltage protection chip, a first switch circuit and a fuse; the first end of the fuse is electrically connected to the positive connecting end of the battery cell, the second end of the fuse is electrically connected to the positive connecting end of the host, and the third end of the fuse is electrically connected to the first switch circuit; the first overvoltage protection chip is electrically connected to the first switch circuit and used for controlling the first switch circuit to be conducted when the voltage of the battery is higher than a first preset voltage, so that the third end of the fuse is electrically connected to the negative electrode connecting end of the battery core; a first test point is arranged between the first overvoltage protection chip and the first switch circuit, and a second test point is arranged between the first end of the fuse and the positive electrode connecting end of the battery core. This application can detect the overvoltage protection function of battery protection shield, prevents effectively that heavy current from strikeing and causing the fuse damage.

Description

Battery protection plate, battery and detection method

Technical Field

The application relates to the technical field of battery detection, in particular to a battery protection plate, a battery and a detection method.

Background

The battery protection board is used for charging and discharging protection of the battery and comprises a fuse, a switch circuit and an overvoltage protection chip. When the voltage of battery surpassed certain voltage value, overvoltage protection chip control switch circuit switched on for fuse ground connection, with the voltage that reduces electric core link and the electric current on the fuse, fuse fusing after continuously overcharging, thereby play the effect of protection battery overcharge. At present, when the overvoltage protection function of a battery protection board is detected, the function of a fuse is difficult to ensure to be normal.

Disclosure of Invention

In view of this, the present application provides a battery protection board, a battery and a detection method, which not only can detect the overvoltage protection function of the battery protection board, but also can effectively prevent the fuse damage caused by the large current impact in the detection process.

The battery protection board comprises a battery cell positive electrode connecting end, a battery cell negative electrode connecting end, a host machine positive connecting end, a host machine negative connecting end and a first overvoltage protection circuit, wherein the first overvoltage protection circuit comprises a first overvoltage protection chip, a first switch circuit and a fuse; the first end of the fuse is electrically connected to the positive connecting end of the battery core, the second end of the fuse is electrically connected to the positive connecting end of the host, and the third end of the fuse is electrically connected to the first switch circuit; the first overvoltage protection chip is electrically connected to the first switch circuit, and is used for controlling the first switch circuit to be conducted when the voltage of the battery is higher than a first preset voltage, so that the third end of the fuse is electrically connected to the cell cathode connecting end; a first test point is arranged between the first overvoltage protection chip and the first switch circuit, and a second test point is arranged between the first end of the fuse and the positive connection end of the battery core.

The battery of the present application includes the battery protection plate.

The detection method is used for detecting the battery protection plate and comprises the following steps: acquiring a first test parameter and a second test parameter; and determining whether the fuse is normal or not according to the first test parameter and the second test parameter.

In one embodiment, the detection method includes: inputting a first voltage signal between the cell positive connecting end and the cell negative connecting end, wherein a voltage value U1 of the first voltage signal and a rated voltage value U0 of the battery meet the following conditions: U1/U0 is 0.8-1.1; taking a voltage signal between the host positive connecting end and the host negative connecting end as the first test parameter; inputting a second voltage signal at the first test point, wherein the voltage value U2 of the second voltage signal and the rated voltage value U0 of the battery meet the following conditions: U2/U0 is 0.7-1.5; taking a resistance signal between the second test point and the cell cathode connecting end as the second test parameter; and if the first test parameter is larger than a first threshold value and the second test parameter is smaller than a second threshold value, determining that the fuse is normal.

In one embodiment, the detection method further includes: a third test point is arranged between the first overvoltage protection chip and the first switch circuit; inputting a third voltage signal between the cell positive connecting end and the cell negative connecting end, wherein a voltage value U3 of the third voltage signal and a rated voltage value U0 of the battery meet the following requirements: U3/U0 is 0.8-1.1; taking the voltage signal of the third test point as a third test parameter; inputting a fourth voltage signal between the cell positive connecting end and the cell negative connecting end, wherein a voltage value U4 of the fourth voltage signal and a rated voltage value U0 of the battery meet the following conditions: U4/U0 is 1.15-2; inputting a fifth voltage signal at the first test point, wherein a voltage value U5 of the fifth voltage signal satisfies: u5 is more than or equal to 0V and less than or equal to 1.5V; taking the voltage signal of the third test point as a fourth test parameter; and if the third test parameter is smaller than a third threshold value and the fourth test parameter is larger than a fourth threshold value, determining that the first overvoltage protection chip is normal.

In one embodiment, the detection method further includes: inputting a sixth voltage signal at the first test point, wherein a voltage value U6 of the sixth voltage signal and a rated voltage value U0 of the battery meet the following conditions: U6/U0 is 0.7-1.5; taking a resistance signal between the second test point and the cell cathode connecting end as a fifth test parameter; inputting a seventh voltage signal at the first test point, wherein a voltage value U7 of the seventh voltage signal satisfies: u7 is more than or equal to 0V and less than or equal to 1.5V; taking a resistance signal between the second test point and the cell cathode connecting end as a sixth test parameter; and if the fifth test parameter is smaller than a fifth threshold value and the sixth test parameter is larger than a sixth threshold value, determining that the first switch circuit is normal.

This application is through setting up first test point and second test point on the battery protection shield, when the overvoltage protection function of detecting the battery protection shield, at first test point input voltage signal, detects resistance signal between second test point and electric core negative pole link, not only can detect the overvoltage protection function of battery protection shield, can also prevent effectively that heavy current from strikeing and causing the fuse damage.

Drawings

Fig. 1 is a schematic structural view of a battery protection plate in the prior art.

Fig. 2 is a schematic view of the structure of a battery protection plate in embodiment 1.

Fig. 3 is a schematic view of the structure of a battery protection plate in embodiment 2.

Fig. 4 is a schematic structural view of a battery protection plate in embodiment 3.

Fig. 5 is a flowchart of a method of inspecting a battery protection board in embodiment 4.

Fig. 6 is a flowchart of the substep of step S51 in fig. 5.

Fig. 7 is a flowchart of a method of inspecting a battery protection board in embodiment 5.

Fig. 8 is a flowchart of the substep of step S53 in fig. 7.

Fig. 9 is a flowchart of a method of inspecting a battery protection board in embodiment 6.

Fig. 10 is a flowchart of the substep of step S55 in fig. 9.

Fig. 11 is a schematic view of the structure of the battery.

Description of the main elements

10 Battery protection plate

B + battery cell positive electrode connecting end

B-cell cathode connecting end

Positive connection end of PACK + host

Negative connecting end of PACK-host

100 first overvoltage protection circuit

F1 fuse

11 first switching circuit

IC1 first overvoltage protection chip

T1 first test point

T2 second test point

20 external detection device

21 simulation battery cell output module

22 voltage output module

23 resistance acquisition module

24 voltage acquisition module

R resistance

T3 third test point

200 second overvoltage protection circuit

IC2 second overvoltage protection chip

12 second switching circuit

Q1 first field effect transistor

Q2 second field effect transistor

30 cell

31 electric core

32 battery management system

Detailed Description

In order that the above objects, features and advantages of the present application can be more clearly understood, a detailed description of the present application will be given below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict. In the following description, numerous specific details are set forth to provide a thorough understanding of the present application, and the described embodiments are merely a subset of the embodiments of the present application and are not intended to be a complete embodiment.

It should be noted that, although a logical order is illustrated in the flowcharts, in some cases, the steps illustrated or described may be performed in an order different from that in the flowcharts. The methods disclosed in embodiments of the present application include one or more steps or actions for achieving the methods. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

Fig. 1 is a schematic structural view of a battery protection plate 10 in the prior art. As shown in fig. 1, the battery protection board 10 includes a cell positive connection end B +, a cell negative connection end B-, a host positive connection end PACK +, a host negative connection end PACK-, and a first overvoltage protection circuit 100, where the first overvoltage protection circuit 100 includes a fuse F1, a first switch circuit 11, and a first overvoltage protection chip IC 1. A first end of the fuse F1 is electrically connected to the cell positive connection terminal B +, a second end of the fuse F1 is electrically connected to the host positive connection terminal PACK +, and a third end of the fuse F1 is electrically connected to the first switch circuit 11. The first overvoltage protection chip IC1 is electrically connected to the first switch circuit 11, and the first overvoltage protection chip IC1 is configured to control the first switch circuit 11 to conduct when the voltage of the battery is higher than a first preset voltage, so that the third terminal of the fuse F1 is electrically connected to the cell negative connection terminal B-.

And the battery cell positive electrode connecting end B + and the battery cell negative electrode connecting end B-are used for being electrically connected to the positive electrode and the negative electrode of the battery cell. And the host positive connecting end PACK + and the host negative connecting end PACK-are electrically connected to the positive end and the negative end of the host. The battery comprises the battery core and the battery protection plate 10. The host may be a charging device or a load. When the battery discharges, the host is a load, and the load is used for consuming the electric quantity of the battery. When the battery is charged, the host is a charging device, and the charging device is used for charging the battery.

The battery cell negative electrode connecting end B-is directly connected with the host negative connecting end PACK-, and the component on the battery protection board 10 is electrically connected to the battery cell negative electrode connecting end B-or the host negative connecting end PACK-, which can be regarded as the component grounding.

When the voltage of the battery is higher than a first preset voltage (for short, a secondary protection voltage), the first overvoltage protection chip IC1 enables the output level to drive the first switch circuit 11 connected to the fuse F1 to the ground to be turned on, so that the first switch circuit forms a loop to directly pull down the voltage input to the battery core end and the excessive current on the fuse F1, and the fuse F1 is fused after continuous overcharge, thereby protecting the overcharge of the battery.

At present, when the secondary overvoltage protection function of the battery protection board 10 is detected, a large current may pass through the fuse F1, so that a certain damage may be caused to the fuse F1.

Based on this, the application provides a battery protection shield, battery and detection method, can solve effectively when detecting the overvoltage protection function of battery protection shield, is difficult to guarantee the problem that the fuse function is normal.

The following embodiments 1 to 3 are all structural examples of the battery protection sheet 10 of the present application.

Example 1

Fig. 2 is a schematic structural view of a battery protection sheet 10 in embodiment 1. Referring to fig. 1 and fig. 2 together, the difference between fig. 2 and fig. 1 is that a first test point T1 is disposed between the first overvoltage protection chip IC1 and the first switch circuit 11, and a second test point T2 is disposed between the first end of the fuse F1 and the cell positive connection end B +.

When the first test point T1 and the second test point T2 are used for testing the battery protection board 10, an external testing device 20 is connected to an access point of the battery protection board 10. The external detection device 20 includes a simulation cell output module 21, a voltage output module 22, and a resistance acquisition module 23. The analog cell output module 21 is configured to input a voltage signal between the cell positive electrode connection end B + and the cell negative electrode connection end B-. The voltage output module 22 is used for inputting a voltage signal at the first test point T1. The resistance acquisition module 23 is configured to acquire a resistance signal between the second test point T2 and the cell negative electrode connection end B-.

In one embodiment, the first switch circuit 11 is a field effect transistor, a gate of the field effect transistor is electrically connected to the first overvoltage protection chip IC1, a source of the field effect transistor is electrically connected to the cell negative connection terminal B ", and a drain of the field effect transistor is electrically connected to the third terminal of the fuse F1. The first overvoltage protection chip IC1 controls the field effect transistor to be switched on or off by controlling the voltage value input to the grid electrode of the field effect transistor.

In other embodiments, the first switch circuit 11 may be a transistor or a programmable switch, and both of the transistor and the programmable switch are controlled by the first overvoltage protection chip IC 1.

Example 2

Fig. 3 is a schematic structural view of the battery protection sheet 10 in embodiment 2. Referring to fig. 2 and 3, the difference between fig. 3 and 2 is that the first overvoltage protection circuit 100 further includes a resistor R electrically connected between the first switch circuit 11 and the first overvoltage protection chip IC 1. The first test point T1 is disposed between the first switch circuit 11 and the resistor R, and a third test point T3 is disposed between the resistor R and the first overvoltage protection chip IC 1.

The third test point T3 is an access point for accessing an external test device 20 to the battery protection board 10 when testing the battery protection board 10. The external test device 20 further includes a voltage collecting module 24, and the voltage collecting module 24 is configured to collect a voltage signal at the third test point T3.

The resistor R is used for voltage division, when an overvoltage performance test is performed on the first overvoltage protection chip IC1, a low-level voltage signal is input at one end of the resistor R close to the first switch circuit 11 (i.e., the first test point T1), and due to the existence of the resistor R, the output voltage of the first overvoltage protection chip IC1 can be collected at the third test point T3, and the first switch circuit 11 is not turned on due to the change of the output voltage of the first overvoltage protection chip IC1, so that a large current can be prevented from passing through the third end of the fuse F1 in the test process, and the fuse F1 is damaged. The resistor R may also be used for limiting a current to prevent an excessive current value between the first overvoltage protection chip IC1 and the first switch circuit 11 from damaging the first switch circuit 11. The resistor R can be a fixed resistor or a variable resistor, and the resistance value can be set according to actual conditions. In one embodiment, the resistance value of the resistor R is 5.1k ohms (Ω).

Example 3

Fig. 4 is a schematic structural view of a battery protection plate 10 in embodiment 3. Referring to fig. 4 and fig. 3 together, the difference between fig. 4 and fig. 3 is that the battery protection board 10 further includes a second overvoltage protection circuit 200, the second overvoltage protection circuit 200 includes a second overvoltage protection chip IC2 and a second switch circuit 12, and the second switch circuit 12 is electrically connected between the battery cell positive connection terminal B + and the host positive connection terminal PACK +. The second overvoltage protection chip IC2 is electrically connected to the second switch circuit 12, and the second overvoltage protection chip IC2 is configured to control the second switch circuit 12 to be disconnected when the voltage of the battery is higher than a second preset voltage, so that the cell positive connection terminal B + is disconnected from the host positive connection terminal PACK +.

When the voltage of the battery is higher than a second preset voltage (primary protection voltage for short), the second overvoltage protection chip IC2 enables the output level to drive the second switch circuit 12 which connects the fuse F1 to the host positive connection terminal PACK + to be disconnected, so that the battery cell positive connection terminal B + is disconnected from the host positive connection terminal PACK +, thereby protecting the battery from overcharging. When the voltage of the battery is smaller than the primary protection voltage, the second switch circuit 12 is enabled to be turned on, so that the battery cell positive connection end B + is connected with the host computer positive connection end PACK + in a recovery manner, and the above process is a primary overvoltage protection and recovery process of the battery protection board 10.

In one embodiment, the second switch circuit 12 includes a first fet Q1 and a second fet Q2 in cascade. The source of the first fet Q1 is electrically connected to the source of the second fet Q2, the drain of the first fet Q1 is electrically connected to the second end of the fuse F1, the gates of the first fet Q1 and the second fet Q2 are electrically connected to the second overvoltage protection chip IC2, and the drain of the second fet Q2 is electrically connected to the positive host connection PACK +. The second overvoltage protection chip IC2 controls the first fet Q1 and the second fet Q2 to be turned on or off by controlling the voltage values input to the gate of the first fet Q1 and the gate of the second fet Q2.

It is understood that other embodiments of the second switch circuit 12 can refer to the specific embodiment of the first switch circuit 11 in example 1.

Based on the battery protection sheet 10 in the above-described embodiments 1 to 3, each of the embodiments 4 to 6 is a method embodiment of inspecting the battery protection sheet 10.

Example 4

Fig. 5 is a flowchart of a method of inspecting the battery protection plate 10 described in embodiment 4. Fig. 6 is a flowchart of the substep of step S51 in fig. 5. Referring to fig. 2 to 6, the detecting method includes the following steps:

s51, obtaining the first test parameter and the second test parameter.

The method for obtaining the first test parameter comprises the following substeps:

and S511, inputting a first voltage signal between the cell positive electrode connecting end B + and the cell negative electrode connecting end B-.

In the embodiment of the application, the voltage value U1 of the first voltage signal and the rated voltage value U0 of the battery satisfy: U1/U0 is 0.8-1.1. In one embodiment, the voltage value U1 of the first voltage signal and the rated voltage value U0 of the battery satisfy: U1/U0 equals 1.

In this embodiment, the battery may be a single-cell battery, and a rated voltage value U0 of the battery satisfies: u0 is more than or equal to 2V and less than or equal to 4V. In other embodiments, the cells may also be batteries in series or in parallel.

S512, the voltage signal between the positive connecting end PACK + of the host and the negative connecting end PACK-of the host is used as the first test parameter.

And detecting a voltage signal between the positive connecting end PACK + of the host and the negative connecting end PACK-of the host to acquire the first test parameter.

Acquiring a second test parameter, comprising the following sub-steps:

s513, a second voltage signal is input to the first test point T1.

In the embodiment of the application, the voltage value U2 of the second voltage signal and the rated voltage value U0 of the battery satisfy: U2/U0 is 0.7-1.5. In one embodiment, the voltage value U2 of the second voltage signal and the rated voltage value U0 of the battery satisfy: U2/U0 equals 1. By inputting a high level voltage to the first test point T1, the first switch circuit 11 is turned on, and the third terminal of the fuse F1 is connected to the cell negative connection terminal B-.

And S514, taking a resistance signal between the second test point T2 and the cell cathode connecting end B-as the second test parameter.

And detecting a resistance signal between the second test point T2 and the battery cell negative electrode connecting end B-to obtain the second test parameter.

S52, determining whether the fuse F1 is normal according to the first test parameter and the second test parameter.

Specifically, if the first test parameter is greater than a first threshold value and the second test parameter is less than a second threshold value, it is determined that the fuse F1 is normal.

In the embodiment of the present application, the first threshold and the second threshold may be set according to actual situations. In one embodiment, the first threshold is a voltage value of 0.8U1, and the second threshold is a resistance value of 1 Ω. When the first test parameter is larger than the first threshold value, the connection between the first end and the second end of the fuse F1 is normal. Further, when the second test parameter is smaller than the second threshold, it indicates that the connection between the first terminal and the third terminal of the fuse F1 is normal. In the embodiment of the application, when the second test parameter is obtained, a voltage signal does not need to be applied between the cell positive electrode connecting end B + and the cell negative electrode connecting end B-, and only a very small current during resistance detection passes through the third end of the fuse F1, so that damage to the fuse F1 due to large current impact can be prevented.

Example 5

Fig. 7 is a flowchart of a method for inspecting the battery protection plate 10 according to embodiment 4. Fig. 8 is a flowchart of the substep of step S53 in fig. 7. Referring to fig. 3 to 8, a third test point T3 is disposed on the battery protection board 10 between the first overvoltage protection chip IC1 and the first switch circuit 11, the third test point T3 and the first test point T1 are respectively located at two ends of the resistor R, wherein the third test point T3 is located at an end close to the first overvoltage protection chip IC 1. Embodiment 5 differs from embodiment 4 in that embodiment 5 is a test method for further determining whether the first overvoltage protection chip IC1 is normal. On the basis of embodiment 4, the detection method further comprises the following steps:

and S53, acquiring a third test parameter and a fourth test parameter.

The third test parameter obtaining step includes the following substeps:

and S531, inputting a third voltage signal between the cell positive electrode connecting end B + and the cell negative electrode connecting end B-.

In the embodiment of the present application, the voltage value U3 of the third voltage signal and the rated voltage value U0 of the battery satisfy: U3/U0 is 0.8-1.1. In one embodiment, the voltage value U3 of the third voltage signal and the rated voltage value U0 of the battery satisfy: U3/U0 equals 1.

S532, using the voltage signal of the third test point T3 as the third test parameter.

And detecting the voltage signal of the third test point T3 to obtain the third test parameter.

Acquiring a fourth test parameter, comprising the following sub-steps:

and S533, inputting a fourth voltage signal between the cell positive electrode connecting end B + and the cell negative electrode connecting end B-.

In the embodiment of the present application, the voltage value U4 of the fourth voltage signal and the rated voltage value U0 of the battery satisfy: U4/U0 is 1.15-2. In one embodiment, the voltage value U4 of the fourth voltage signal and the rated voltage value U0 of the battery satisfy: U4/U0 equals 1.2.

S534, the fifth voltage signal is input to the first test point T1.

In the embodiment of the present application, the voltage value U5 of the fifth voltage signal satisfies: u5 is more than or equal to 0V and less than or equal to 1.5V. In one embodiment, the voltage value U5 of the fifth voltage signal satisfies: u5 ═ 0V. The first switch circuit 11 is always in the off state by inputting the fifth voltage signal less than or equal to 1.5V at the first test point T1. At this time, no matter how the output voltage of the first overvoltage protection chip IC1 changes, the first switch circuit 11 is not turned on, so as to prevent the fuse F1 from being damaged due to a large current passing through the third terminal of the fuse F1 during the test.

S535, using the voltage signal of the third test point T3 as the fourth test parameter.

And detecting the voltage signal of the third test point T3 to obtain the fourth test parameter.

S54, determining whether the first overvoltage protection chip IC1 is normal according to the third test parameter and the fourth test parameter.

Specifically, if the third test parameter is smaller than a third threshold value and the fourth test parameter is larger than a fourth threshold value, it is determined that the first overvoltage protection chip IC1 is normal.

In the embodiment of the present application, the third threshold and the fourth threshold may be set according to actual situations. In one embodiment, the third threshold is a voltage value of 2V, and the fourth threshold is a voltage value of 2.5V. When the third test parameter is smaller than the third threshold and the fourth test parameter is larger than the fourth threshold, it indicates that the first overvoltage protection chip IC1 can normally recognize the voltage between the cell positive connection terminal B + and the cell negative connection terminal B +, and output a corresponding voltage signal to the first switch circuit 11.

Example 6

Fig. 9 is a flowchart of a method for inspecting the battery protection plate 10 according to embodiment 4. Fig. 10 is a flowchart of the substep of step S55 in fig. 9. Referring to fig. 3 to 10, embodiment 6 differs from embodiment 4 in that embodiment 6 is a detection method for further determining whether the first switch circuit 11 is normal. On the basis of embodiment 4, the detection method further comprises the following steps:

and S55, acquiring a fifth test parameter and a sixth test parameter.

The fifth test parameter obtaining method comprises the following substeps:

s551, inputting the sixth voltage signal to the first test point T1.

In the embodiment of the present application, the voltage value U6 of the sixth voltage signal and the rated voltage value U0 of the battery satisfy: U6/U0 is 0.7-1.5. In one embodiment, the voltage value U6 of the sixth voltage signal and the rated voltage value U0 of the battery satisfy: U6/U0 equals 1.

And S552, taking a resistance signal between the second test point T2 and the cell cathode connecting end B-as a fifth test parameter.

And detecting a resistance signal between the second test point T2 and the cell cathode connecting end B-to obtain the fifth test parameter.

Acquiring a sixth test parameter, comprising the following sub-steps:

s553, a seventh voltage signal is input to the first test point T1.

In the embodiment of the present application, the voltage value U7 of the seventh voltage signal satisfies: u7 is more than or equal to 0V and less than or equal to 1.5V. In one embodiment, the voltage value U7 of the seventh voltage signal satisfies: u7 ═ 0V.

And S554, taking a resistance signal between the second test point T2 and the battery cell negative electrode connecting end B-as a sixth test parameter.

And detecting a resistance signal between the second test point T2 and the cell cathode connecting end B-to obtain the sixth test parameter.

S56, determining whether the first switch circuit 11 is normal according to the fifth test parameter and the sixth test parameter.

Specifically, if the fifth test parameter is smaller than a fifth threshold and the sixth test parameter is larger than a sixth threshold, it is determined that the first switch circuit 11 is normal.

In the embodiment of the present application, the fifth threshold and the sixth threshold may be set according to actual situations. In one embodiment, the fifth threshold is a resistance value of 1 Ω, and the sixth threshold is a resistance value of 100k Ω. When the fifth test parameter is smaller than the fifth threshold, it indicates that the first switch circuit 11 can be normally turned on. Further, when the sixth test parameter is greater than the sixth threshold, it indicates that the first switch circuit 11 can be normally turned off. In this embodiment, since there is no voltage signal between the cell positive connection terminal B + and the cell negative connection terminal B —, only a very small current during resistance detection passes through the fuse F1, so that damage to the fuse F1 due to a large current impact can be prevented.

It is understood that the embodiments of example 5 and example 6 can be combined with each other in the examples of the present application.

It should be noted that the obtaining order of each test parameter is not fixed, for example, the first test parameter may be obtained first and then the second test parameter may be obtained, or the second test parameter may be obtained first and then the first test parameter may be obtained. When the following test parameters are acquired, the irrelevant signals applied to the battery protection board 10 for acquiring the preceding test parameters are removed accordingly, for example, when the second test parameters are acquired, the first voltage signals applied to the battery protection board 10 for acquiring the first test parameters are removed.

Fig. 11 is a schematic structural view of the battery 30. As shown in fig. 11, the Battery 30 includes a Battery cell 31, a Battery protection plate 10, and a Battery Management System (BMS) 32, and the specific embodiment of the Battery protection plate 10 can refer to embodiments 1 to 3. The battery management system 32 is used to implement the detection method as described in embodiments 4 to 6.

The embodiments of the present application have been described in detail with reference to the drawings, but the present application is not limited to the embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present application. Furthermore, the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

Claims

1. A battery protection board comprises a battery cell positive electrode connecting end, a battery cell negative electrode connecting end, a host machine positive connecting end, a host machine negative connecting end and a first overvoltage protection circuit, and is characterized in that the first overvoltage protection circuit comprises a first overvoltage protection chip, a first switch circuit and a fuse;

the first end of the fuse is electrically connected to the positive connecting end of the battery core, the second end of the fuse is electrically connected to the positive connecting end of the host, and the third end of the fuse is electrically connected to the first switch circuit;

the first overvoltage protection chip is electrically connected to the first switch circuit, and is used for controlling the first switch circuit to be conducted when the voltage of the battery is higher than a first preset voltage, so that the third end of the fuse is electrically connected to the cell cathode connecting end;

a first test point is arranged between the first overvoltage protection chip and the first switch circuit, and a second test point is arranged between the first end of the fuse and the positive connection end of the battery core.

2. The battery protection board of claim 1, wherein the first switch circuit is a field effect transistor, a gate of the field effect transistor is electrically connected to the first overvoltage protection chip, a source of the field effect transistor is electrically connected to the cell negative connection terminal, and a drain of the field effect transistor is electrically connected to the third terminal of the fuse.

3. The battery protection panel of claim 2, wherein the first overvoltage protection circuit further comprises a resistor electrically connected between the gate of the fet and the first overvoltage protection chip;

the first test point is arranged between the grid of the field effect transistor and the resistor, and a third test point is arranged between the resistor and the first overvoltage protection chip.

4. The battery protection panel of claim 1, further comprising a second overvoltage protection circuit, wherein the second overvoltage protection circuit comprises a second overvoltage protection chip and a second switch circuit, and the second switch circuit is electrically connected between the cell positive connection terminal and the host positive connection terminal;

the second overvoltage protection chip is electrically connected to the second switch circuit, and is used for controlling the second switch circuit to be disconnected when the voltage of the battery is higher than a second preset voltage, so that the positive connection end of the battery core is disconnected with the positive connection end of the host machine.

5. A battery characterized by comprising the battery protective plate as recited in any one of claims 1 to 4.

6. An inspection method for inspecting the battery protection sheet as set forth in any one of claims 1 to 4, comprising:

acquiring a first test parameter and a second test parameter;

and determining whether the fuse is normal or not according to the first test parameter and the second test parameter.

7. The detection method of claim 6, wherein said obtaining a first test parameter comprises:

inputting a first voltage signal between the cell positive connecting end and the cell negative connecting end, wherein a voltage value U1 of the first voltage signal and a rated voltage value U0 of the battery meet the following conditions: U1/U0 is 0.8-1.1;

and taking a voltage signal between the host positive connecting end and the host negative connecting end as the first test parameter.

8. The detection method of claim 7, wherein said obtaining a second test parameter comprises:

inputting a second voltage signal at the first test point, wherein the voltage value U2 of the second voltage signal and the rated voltage value U0 of the battery meet the following conditions: U2/U0 is 0.7-1.5;

and taking the resistance signal between the second test point and the cell cathode connecting end as the second test parameter.

9. The method for testing as defined in claim 8, wherein said determining whether said fuse is normal based on said first and second test parameters comprises:

and if the first test parameter is larger than a first threshold value and the second test parameter is smaller than a second threshold value, determining that the fuse is normal.

10. The detection method of claim 6, further comprising:

inputting a third voltage signal between the cell positive connecting end and the cell negative connecting end, wherein a voltage value U3 of the third voltage signal and a rated voltage value U0 of the battery meet the following requirements: U3/U0 is 0.8-1.1;

taking a voltage signal of a third test point as a third test parameter, wherein the third test point is arranged between the first overvoltage protection chip and the first switch circuit;

inputting a fourth voltage signal between the cell positive connecting end and the cell negative connecting end, wherein a voltage value U4 of the fourth voltage signal and a rated voltage value U0 of the battery meet the following conditions: U4/U0 is 1.15-2;

inputting a fifth voltage signal at the first test point, wherein a voltage value U5 of the fifth voltage signal satisfies: u5 is more than or equal to 0V and less than or equal to 1.5V;

taking the voltage signal of the third test point as a fourth test parameter;

and if the third test parameter is smaller than a third threshold value and the fourth test parameter is larger than a fourth threshold value, determining that the first overvoltage protection chip is normal.

11. The detection method of claim 6, further comprising:

inputting a sixth voltage signal at the first test point, wherein a voltage value U6 of the sixth voltage signal and a rated voltage value U0 of the battery meet the following conditions: U6/U0 is 0.7-1.5;

taking a resistance signal between the second test point and the cell cathode connecting end as a fifth test parameter;

inputting a seventh voltage signal at the first test point, wherein a voltage value U7 of the seventh voltage signal satisfies: u7 is more than or equal to 0V and less than or equal to 1.5V;

taking a resistance signal between the second test point and the cell cathode connecting end as a sixth test parameter;

and if the fifth test parameter is smaller than a fifth threshold value and the sixth test parameter is larger than a sixth threshold value, determining that the first switch circuit is normal.