Lithium battery protection module, lithium battery module and lithium battery interface anti-sparking method

Abstract

The invention provides a lithium battery protection module, a lithium battery module and a lithium battery interface anti-sparking method, and the module comprises a communication unit which communicates with external equipment; the pre-discharge unit is connected in parallel with the two ends of the discharge tube; the control unit is used for generating on-off control signals of the pre-discharging unit, the discharging tube and the charging tube and judging whether external equipment is matched or not; when an adaptive external device is connected, the sparking phenomenon is avoided by limiting the current flowing through the lithium battery. According to the lithium battery protection module, the lithium battery module and the lithium battery interface anti-sparking method, the lithium battery protection module is in a dormant state during standing, the lithium battery protection module closes the charging tube and the discharging tube, other parts are in a low-power-consumption operation state, and when charging or discharging is needed, the charging tube and the discharging tube are opened for protection; and the charging and discharging current is limited when the external equipment is connected, so that the interface sparking phenomenon is avoided.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a lithium battery protection module, a lithium battery module and a lithium battery interface spark prevention method. Background Art

[0002] Since lithium batteries have obvious advantages over lead-acid batteries, such as light weight, high energy density, and long cycle life, they are increasingly used in two-wheeled vehicles, sightseeing vehicles, forklifts, and other fields. In order to ensure the safe and reliable long-term use of lithium batteries, it is necessary to configure corresponding protection boards to monitor and protect the operating status of lithium batteries; at the same time, in lithium battery applications, it is necessary to configure matching chargers or loads to ensure that lithium batteries can operate safely, reliably, and efficiently during the charging and discharging process. However, the following problems still exist when using lithium batteries:

[0003] 1. Sparking phenomenon at the interface: When the lithium battery is connected to a load or charger, sparking can often be observed. After long-term use, the interface is damaged and cannot be charged or discharged.

[0004] 2. With the increasing number of lithium battery manufacturers, charger manufacturers, controller manufacturers, and vehicle manufacturers, the types of vehicle models, lithium battery types, chargers, etc. used by end customers are diverse. When end customers use them, fire and explosion accidents often occur due to the incompatibility between chargers and lithium batteries, or between lithium batteries and load control.

[0005] Therefore, how to avoid the sparking phenomenon at the lithium battery interface and improve the safety of lithium battery use has become one of the problems that technical personnel in this field need to solve urgently.

[0006] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present invention and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the present invention. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a lithium battery protection module, a lithium battery module and a lithium battery interface anti-spark method, which are used to solve the problems of lithium battery interfaces being prone to sparks and having poor safety in use in the prior art.

[0008] In order to achieve the above-mentioned object and other related objects, the present invention provides a lithium battery protection module, which at least includes:

[0009] Communication unit, control unit, discharge tube, charging tube and pre-discharge unit;

[0010] The communication unit communicates with an external device;

[0011] The discharge tube is connected in series with the charging tube, and the pre-discharge unit is connected in parallel to both ends of the discharge tube;

[0012] The control unit is connected to the communication unit, the discharge tube, the charging tube and the pre-discharge unit, and obtains the lithium battery status signal, which is used to generate the switch control signal of the pre-discharge unit, the discharge tube and the charging tube, and judge whether the external device is adapted; when the adapted external device is connected, the current flowing through the lithium battery is limited to avoid sparking;

[0013] Wherein, the external device is a load and / or a charger.

[0014] Optionally, the pre-amplifier unit includes a pre-amplifier tube and a current-limiting resistor; the pre-amplifier tube and the current-limiting resistor are connected in series, and the control end of the pre-amplifier tube is connected to the output end of the control unit.

[0015] More optionally, the control unit is connected to a connection node between the discharge tube and the charging tube, and controls the pre-discharge unit to be turned on or off based on a voltage at the connection node between the discharge tube and the charging tube.

[0016] More optionally, the control unit is connected to the positive electrode of the lithium battery, and when connected to an adapted charger, it notifies the charger to adjust the charging current based on the positive electrode voltage of the lithium battery.

[0017] In order to achieve the above-mentioned purpose and other related purposes, the present invention also provides a lithium battery interface spark prevention method, which is implemented based on the above-mentioned lithium battery protection module, and the lithium battery interface spark prevention method at least includes:

[0018] When no external device is connected, the pre-discharge unit, discharge tube and charging tube are all in the off state;

[0019] When a load is connected, determining whether the load is suitable;

[0020] If not, the pre-discharge unit, the discharge tube and the charging tube are all kept in a closed state;

[0021] If they are compatible, the pre-discharge unit and the charging tube are turned on, and the lithium battery supplies power to the load with a first discharge current; when the load is charged to a first preset voltage, the pre-discharge unit is turned off and the discharge tube is turned on, and the lithium battery supplies power to the load with a second discharge current;

[0022] When a charger is connected, determining whether the charger is compatible;

[0023] If not, the pre-discharge unit, the discharge tube and the charging tube are all kept in a closed state;

[0024] If compatible, the discharge tube and the charging tube are turned on, and the charger is notified to charge the lithium battery with a first charging current; when the lithium battery is charged to a second preset voltage, the charger is notified to charge the lithium battery with a second charging current;

[0025] The first discharging current is smaller than the second discharging current, and the first charging current is smaller than the second charging current.

[0026] Optionally, when no external device is connected, the lithium battery protection module is in sleep mode, and when a load or charger is connected, the lithium battery protection module is activated; if the load or the charger is not compatible, the lithium battery protection module switches back to sleep mode after a preset period of time.

[0027] Optionally, the first preset voltage is lower than the full charge voltage of the lithium battery, and the second preset voltage is lower than the full charge voltage of the lithium battery.

[0028] More optionally, whether the load is charged to the first preset voltage is determined based on the voltage of the node connecting the discharge tube and the charging tube.

[0029] More optionally, whether the lithium battery is charged to the second preset voltage is determined based on the positive electrode voltage of the lithium battery.

[0030] To achieve the above-mentioned object and other related objects, the present invention provides a lithium battery module, which at least comprises:

[0031] Lithium battery and the above-mentioned lithium battery protection module;

[0032] The positive electrode of the lithium battery serves as the positive electrode of the lithium battery module, and the negative electrode is connected to one end of the series structure of the discharge tube and the charging tube; the other end of the series structure of the discharge tube and the charging tube serves as the negative electrode of the lithium battery module.

[0033] As described above, the lithium battery protection module, lithium battery module and lithium battery interface anti-sparking method of the present invention have the following beneficial effects:

[0034] 1. The lithium battery protection module, lithium battery module and lithium battery interface anti-sparking method of the present invention are in a dormant state when stationary. The lithium battery protection module will turn off the charging tube and the discharge tube, and the other parts are in a low-power operation state. When charging or discharging is required, the charging tube and the discharge tube will be turned on for protection.

[0035] 2. The lithium battery protection module, lithium battery module and lithium battery interface spark prevention method of the present invention limit the charge and discharge current when connected to an external device, thereby avoiding the occurrence of interface sparks. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It shows a schematic diagram of the structure of the lithium battery module connected to the load and charger.

[0037] Figure 2 Shown is a schematic structural diagram of the lithium battery protection module and the lithium battery module of the present invention.

[0038] Figure 3 It shows a schematic structural diagram of the lithium battery module of the present invention connected with a load and a charger.

[0039] Figure 4 It shows a flow chart of the method for preventing the lithium battery interface from sparking when connected to a load according to the present invention.

[0040] Figure 5 Shown is a flow chart of the method for preventing a lithium battery interface from sparking when connected to a charger according to the present invention.

[0041] Component number description

[0042] 1 Lithium battery module

[0043] 11 Lithium battery

[0044] 12 Protection board

[0045] 2 Load

[0046] 3. Charger

[0047] 4 Lithium battery module

[0048] 41 Lithium battery protection module

[0049] 41a Communication unit

[0050] 41b Control Unit

[0051] 41c Preamplifier Unit

[0052] 42 Lithium battery DETAILED DESCRIPTION

[0053] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0054] See also Figure 1 to Figure 5It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0055] like Figure 1 As shown, the lithium battery module 1 includes a lithium battery 11 and a protection board 12. The lithium battery module 1 is connected to an external load 2 or a charger 3 through a positive electrode interface P+ (i.e., the positive electrode B+ of the lithium battery) and a negative electrode interface P- to complete the charging and discharging functions. Under normal circumstances, the discharge tube Q1 and the charging tube Q2 in the protection board are both in the on state. When the charger 3 is connected, the charger 3 charges the lithium battery 11 until the lithium battery is fully charged, and the protection board 12 controls the charging tube Q2 to turn off and prohibit further charging. When the load 2 is connected, the lithium battery 11 discharges to the load 2 until the lithium battery 11 is out of power, and the protection board 12 controls the discharge tube Q1 to turn off and prohibit further discharging.

[0056] In this process, when load 2 is connected, if the capacitor voltage of load 2 is relatively low (for example, the load capacitor voltage is 0V), at the moment of connecting load 2, the lithium battery module 1 provides a momentary large current to charge the load capacitor, and the interface will short-circuit and spark, and long-term use will cause damage to the interface. If an unmatched load 2 is used, it will also cause a short-circuit and spark phenomenon when the load is connected, and then trigger the short-circuit protection of the protection board 12, turning off the discharge tube Q1. At this time, the protection board 12 will lock the load 2, causing the lithium battery module 1 to be unable to discharge. In addition, the use of an unmatched load 2 may also cause problems such as failure of the protection board, excessive operating temperature, and reduced battery life.

[0057] In this process, when the charger 3 is connected, if the voltage of the charger 3 is low or the current is small (the charger 3 does not match the lithium battery 11), the lithium battery will not be fully charged, the charging time is too long, and other problems will occur; if the voltage of the charger 3 is high or the current is large (the charger 3 does not match the lithium battery module 1), it will cause the protection board to fail, the battery temperature is abnormal, the interface sparks, the battery catches fire, and other problems. If the load 2 is disconnected when the charger 3 is connected, the voltage of the lithium battery is low, and the charging tube in the protection board is in the open state, since the voltage output by the charger 3 is about the full-charge voltage of the lithium battery, which is much higher than the actual voltage of the lithium battery, the connection will cause a large current charging, and then cause the interface to spark. If the load 2 is not disconnected when the charger 3 is connected, regardless of whether the charging tube Q2 is turned on, the charger 3 will first charge the load capacitor. At the moment the charger 3 is connected, the load capacitor will cause a short-circuit spark phenomenon. Long-term use will cause damage to the interface, and even trigger the charger short-circuit protection, resulting in failure to charge; in this state, if the battery is in the undervoltage protection state, the spark phenomenon is more serious. This phenomenon is common in applications where the load is not often disconnected, such as two-wheeled vehicles and forklifts.

[0058] Therefore, when the lithium battery module is connected to a load or charger, the interface may spark; using a lithium battery with an incompatible charger or load will affect the performance of the lithium battery and even cause safety accidents such as fire and explosion. Based on the above problems, the present invention proposes a lithium battery protection module, a lithium battery module and a lithium battery interface anti-spark method, and the specific scheme is as follows:

[0059] like Figure 2 As shown, the present invention provides a lithium battery protection module 41, and the lithium battery protection module 41 includes:

[0060] The communication unit 41a, the control unit 41b, the discharge tube Q1, the charging tube Q2 and the pre-discharge unit 41c.

[0061] like Figure 2 As shown, the communication unit 41a communicates with an external device, wherein the external device is a charger and / or a load.

[0062] Specifically, the communication unit 41a is used to achieve communication, and any method that can achieve communication between the lithium battery protection module 41 and an external device is applicable to the present invention. As an example, the communication unit 41a adopts a communication method including but not limited to 485, 232 or a one-line communication, which will not be described one by one here.

[0063] like Figure 2 As shown, the discharge tube Q1 is connected in series with the charging tube Q2 to provide a charge and discharge path and realize charge and discharge protection.

[0064] Specifically, in this embodiment, the discharge tube Q1 and the charging tube Q2 are both NMOS tubes; the source of the discharge tube Q1 is connected to the lithium battery, and the drain is connected to the drain of the charging tube Q2; the source of the charging tube Q2 is connected to an external device. In actual use, the discharge tube Q1 and the charging tube Q2 can select the corresponding device type according to needs, and the positions can also be interchanged, as long as they can provide a charging and discharging path and realize charging and discharging protection.

[0065] like Figure 2 As shown, the pre-discharge unit 41c is connected in parallel to both ends of the discharge tube Q1 to provide another discharge path and limit the current in the discharge path.

[0066] Specifically, in this embodiment, the pre-amplifier unit 41c includes a pre-amplifier tube Q3 and a current limiting resistor R1. The pre-amplifier tube Q3 is connected in series with the current limiting resistor R1, and the control end of the pre-amplifier tube Q3 is connected to the output end of the control unit 41b. As an example, the pre-amplifier tube Q3 is implemented by an NMOS tube, the source of the pre-amplifier tube Q3 is connected to the source of the discharge tube Q1, and the drain is connected to the discharge tube Q1 and the drain of the charging tube Q2 via the current limiting resistor R1; in actual use, the pre-amplifier tube Q3 can select the corresponding device type as needed, and the positions of the pre-amplifier tube Q3 and the current limiting resistor R1 can also be interchanged, which is not limited to this embodiment.

[0067] like Figure 2 As shown, the control unit 41b is connected to the communication unit 41a, the discharge tube Q1, the charging tube Q2 and the pre-discharge unit 41c, and obtains the lithium battery status signal, which is used to generate the switch control signal of the pre-discharge unit 41c, the discharge tube Q1 and the charging tube Q2, and judge whether the external device is compatible; when the compatible external device is connected, the spark phenomenon is avoided by limiting the current flowing through the lithium battery.

[0068] Specifically, the control unit 41b determines whether the external device is adapted based on the information obtained by the communication unit 41a. When the adapted external load is connected, the pre-discharge unit 41c and the charging tube Q2 are controlled to be turned on, and the discharge tube Q1 is turned off. At this time, the control unit 41b provides the load with a first discharge current Idisch1 based on the pre-discharge unit 41c; when the load is charged to the first preset voltage, the discharge tube Q1 and the charging tube Q2 are controlled to be turned on, and the pre-discharge unit 41c is turned off. At this time, the control unit 41b provides the load with a second discharge current Idisch2 (greater than the first discharge current Idisch1) based on the discharge tube Q1. When an adapted external charger is connected, the discharge tube Q1 and the charging tube Q2 are controlled to be turned on, the pre-discharge unit 41c is turned off or on, and a charging notification is sent to the charger, so that the charger charges the lithium battery with a first charging current Ich1; when the lithium battery is charged to a second preset voltage, the control unit 41b sends a charging notification to the charger, so that the charger charges the lithium battery with a second charging current Ich2 (greater than the first charging current Ich1).

[0069] As an example, the control unit 41b is connected to the connection node of the discharge tube Q1 and the charging tube Q2, and controls the pre-discharge unit 41c to be turned on or off based on the voltage VM of the connection node between the discharge tube Q1 and the charging tube Q2; that is, when the voltage VM of the connection node between the discharge tube Q1 and the charging tube Q2 reaches a first set voltage (the first set voltage is less than the full charge voltage of the lithium battery), it is determined that the load is charged to the first preset voltage; in actual use, any connection node that can reflect the voltage on the load can be connected to the control unit 41b, including but not limited to the source of the charging tube Q2, the source of the discharge tube Q1, and the connection nodes of each battery in the lithium battery, and is not limited to this embodiment.

[0070] As an example, the control unit 41b is connected to the positive electrode B+ of the lithium battery, and notifies the charger to adjust the charging current based on the positive electrode voltage of the lithium battery; that is, when the positive electrode voltage of the lithium battery reaches a second set voltage (the second set voltage is less than the full charge voltage of the lithium battery), it is determined that the lithium battery is charged to a second preset voltage; in actual use, any connection node that can reflect the lithium battery voltage can be connected to the control unit 41b, including but not limited to the connection nodes of each battery in the lithium battery, and is not limited to this embodiment.

[0071] Specifically, the control unit 41b also performs charging and discharging protection based on the lithium battery status signal. When the discharge current is too large, the discharge tube Q1 is turned off; when the charging current is too large, the charging tube Q2 is turned off; when the temperature is over or the voltage is over, the corresponding switch tube (the discharge tube Q1 or the charging tube Q2) is turned off; these are not elaborated here.

[0072] It should be noted that when (just) connected to the adapter external device, the control unit 41b limits the charging and discharging current to avoid fire, thereby ensuring the safety of lithium battery use; after a period of charging and discharging, the main circuit is restored to ensure normal charging and discharging and charge and discharge protection.

[0073] like Figure 2 As shown, the present invention further provides a lithium battery module 4 , which includes: a lithium battery protection module 41 and a lithium battery 42 .

[0074] Specifically, the structure of the lithium battery protection module 41 is as described above, and will not be described in detail here. In this embodiment, the lithium battery 42 includes a plurality of batteries, and each battery is connected in series.

[0075] Specifically, the positive electrode B+ of the lithium battery 42 serves as the positive electrode P+ of the lithium battery module 4, and the negative electrode B- of the lithium battery 42 is connected to one end of the series structure of the discharge tube Q1 and the charging tube Q2; the other end of the series structure of the discharge tube Q1 and the charging tube Q2 serves as the negative electrode P- of the lithium battery module 4. In this example, the negative electrode B- of the lithium battery 42 is connected to the source electrode of the discharge tube Q1, and the source electrode of the charging tube Q2 serves as the negative electrode P- of the lithium battery module 4.

[0076] The present invention also provides a method for preventing a lithium battery interface from sparking. In this embodiment, the method for preventing a lithium battery interface from sparking is implemented based on the lithium battery protection module 41 of the present invention. Figure 3 As shown, when the lithium battery module 4 equipped with the lithium battery protection module 41 is used, an external charger 3 and / or load 2 is connected, and the two ends of the charger 3 are respectively connected to the positive electrode (P+) and the negative electrode (P-) of the lithium battery module 4, and the two ends of the load 2 are respectively connected to the positive electrode (P+) and the negative electrode (P-) of the lithium battery module 4. The lithium battery interface anti-sparking method includes:

[0077] When no external device is connected, the pre-discharge unit 41c, the discharge tube Q1 and the charge tube Q2 are all in a closed state.

[0078] When load 2 is connected, determine whether load 2 is adapted;

[0079] If not, the pre-discharge unit 41c, the discharge tube Q1 and the charge tube Q2 are all kept in the off state;

[0080] If compatible, the pre-discharge unit 41c and the charging tube Q2 are turned on, and the lithium battery 42 supplies power to the load with a first discharge current Idisch1; when the load is charged to a first preset voltage Vset1, the pre-discharge unit 41c is turned off and the discharge tube Q1 is turned on, and the lithium battery 42 supplies power to the load 2 with a second discharge current Idisch2.

[0081] When the charger 3 is connected, it is determined whether the charger 3 is suitable;

[0082] If not, the pre-discharge unit 41c, the discharge tube Q1 and the charge tube Q2 are all kept in the off state;

[0083] If compatible, the discharge tube Q1 and the charging tube Q2 are turned on, and the charger 3 is notified to charge the lithium battery 42 with the first charging current Ich1; when the lithium battery is charged to the second preset voltage Vset2, the charger 3 is notified to charge the lithium battery 42 with the second charging current Ich2.

[0084] The first discharging current Idisch1 is smaller than the second discharging current Idisch2 , and the first charging current Ich1 is smaller than the second charging current Ich2 .

[0085] As an implementation of the present invention, when no external device is connected, the lithium battery protection module 41 is in sleep mode, at which time the discharge tube Q1, the charging tube Q2 and the pre-discharge unit 41c are all in a closed state, and the control unit 41b is in standby mode in a low power consumption mode; when an external device is connected, the lithium battery protection module 41 is activated, and each part of the control unit 41b starts working to determine whether the external device is compatible; if it is compatible, the subsequent control continues; if it is not compatible, the lithium battery protection module 41 switches back to sleep mode after a preset time. The preset time is set according to actual needs and will not be described in detail here.

[0086] Specifically, the first preset voltage Vset1 is less than the full charge voltage of the lithium battery 42, and the second preset voltage Vset2 is less than the full charge voltage of the lithium battery 42; the first preset voltage Vset1 and the second preset voltage Vset2 can be configured to be the same value, or they can be configured to be different values. The closer the first preset voltage Vset1 and the second preset voltage Vset2 are to the full charge voltage of the lithium battery 42, the smaller the risk of ignition; the closer the first preset voltage Vset1 and the second preset voltage Vset2 are to zero, the slower the charging and discharging speed; in actual use, the specific values ​​of the first preset voltage Vset1 and the second preset voltage Vset2 can be set after comprehensive consideration according to actual needs.

[0087] In this embodiment, whether the load 2 is charged to the first preset voltage Vset1 is determined based on the voltage VM at the connection node between the discharge tube Q1 and the charging tube Q2. As an example, when the voltage VM at the connection node between the discharge tube Q1 and the charging tube Q2 is less than the full charge voltage of the lithium battery 42, it is determined that the load 2 is charged to the first preset voltage Vset1.

[0088] In this embodiment, whether the lithium battery 42 is charged to the second preset voltage Vset2 is determined based on the positive electrode voltage B+ of the lithium battery 42. As an example, when the voltage of the positive electrode B+ of the lithium battery 42 is less than the full charge voltage of the lithium battery 42, it is determined whether the lithium battery 42 is charged to the second preset voltage Vset2.

[0089] The following is a detailed description of the process of discharging control when the load 2 is connected. Figure 4 As shown, when stationary (load 2 is not connected), the lithium battery protection module 41 is in a dormant state; when the communication unit 41a finds that load 2 is connected, the lithium battery protection module 41 is activated. Since the prevention unit 41c, the discharge tube Q1 and the charging tube Q2 are all in a closed state when the load 2 is connected, the large current ignition phenomenon is avoided when the load is connected. After the lithium battery protection module 41 is activated, the control unit 41b communicates with the communication unit 41a and checks whether the load 2 is an adaptive load based on the acquired signal; if the load is not compatible, the lithium battery protection module 41 continues to sleep after waiting for a period of time; if the load 2 is an adaptive load, the pre-discharge tube Q3 is turned on. Due to the current limiting effect of the current limiting resistor R1, the current of the load 2 is small after it is connected, the load capacitor is charged slowly, and the VM point voltage gradually rises. The control unit 41b continuously detects whether the VM point voltage reaches the set threshold. Generally, the threshold is set to be slightly smaller than the battery voltage, and can also be set according to actual needs. When the voltage at the VM point reaches a set threshold (a first preset voltage Vset1), the control unit 41b controls the discharge tube Q1 and the charging tube Q2 to turn on, opens the main discharge circuit, and turns off the pre-discharge unit 41c.

[0090] The following is a detailed description of the process of discharging control when the load 2 is connected. Figure 5As shown, the lithium battery protection module 41 is in a dormant state when it is stationary; when the communication unit 41a finds that the charger 3 is connected, the lithium battery protection module 41 is activated. Since the discharge tube Q1 and the charging tube Q2 are both in a closed state when the charger 3 is connected, the charger 3 has no output, thus avoiding the large current ignition phenomenon caused by low battery voltage or load not disconnected when the charger is connected. After the charger 3 is connected, the lithium battery protection module 41 communicates with the charger 3 to check whether the charger 3 is an adapter charger; if the charger 3 is not compatible, the lithium battery protection module 41 continues to sleep after waiting for a period of time; if it is an adapter charger, the lithium battery protection module 41 notifies the charger 3 to output the battery voltage and a small current (the first charging current Ich1), and when the external load 2 is not disconnected, the small current charges the external load capacitor and the lithium battery 42, and when the external load 2 is disconnected, the small current charges the lithium battery 42. The lithium battery protection module 41 continuously detects whether the voltage of the B+ interface reaches the set threshold (the second preset voltage Vset2). When the voltage at the VM point reaches the set threshold, the lithium battery protection module 41 controls the charging and discharging to start, opens the main charging circuit, and then the lithium battery protection module 41 notifies the charger to charge in normal mode.

[0091] The present invention can solve the problems of lithium battery life attenuation, abnormal temperature, fire and even explosion caused by incompatible load and charger; avoid the problem of interface sparking when the load is connected; avoid the problem of interface sparking when the charger is connected due to the load not being detached or the battery voltage being low.

[0092] In summary, the present invention provides a lithium battery protection module, a lithium battery module and a lithium battery interface anti-sparking method, including: a communication unit, a control unit, a discharge tube, a charging tube and a pre-discharge unit; the communication unit communicates with an external device; the discharge tube is connected in series with the charging tube, and the pre-discharge unit is connected in parallel to both ends of the discharge tube; the control unit connects the communication unit, the discharge tube, the charging tube and the pre-discharge unit, and obtains a lithium battery status signal for generating a switch control signal of the pre-discharge unit, the discharge tube and the charging tube, and judging whether the external device is adapted; when an adapted external device is connected, the current flowing through the lithium battery is limited to avoid sparking; wherein the external device is a load and / or a charger. The lithium battery protection module, the lithium battery module and the lithium battery interface anti-sparking method of the present invention are in a dormant state when stationary, the lithium battery protection module will turn off the charging tube and the discharge tube, and the other parts are in a low-power operation state. When charging or discharging is required, the charging tube and the discharge tube will be turned on and protected; when an external device is connected, the charging and discharging current is limited, thereby avoiding the occurrence of interface sparking. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0093] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A lithium battery protection module, characterized in that: The lithium battery protection module at least includes: Communication unit, control unit, discharge tube, charging tube and pre-discharge unit; The communication unit communicates with an external device; The discharge tube is connected in series with the charging tube, and the pre-discharge unit is connected in parallel to both ends of the discharge tube; The control unit is connected to the communication unit, the discharge tube, the charging tube and the pre-discharge unit, and obtains the lithium battery status signal, which is used to generate the switch control signal of the pre-discharge unit, the discharge tube and the charging tube, and judge whether the external device is adapted; when the adapted external device is connected, the current flowing through the lithium battery is limited to avoid sparking; Wherein, the external device is a load and / or a charger.

2. The lithium battery protection module according to claim 1, characterized in that: The pre-amplifier unit comprises a pre-amplifier tube and a current limiting resistor; the pre-amplifier tube is connected in series with the current limiting resistor, and the control end of the pre-amplifier tube is connected to the output end of the control unit.

3. The lithium battery protection module according to any one of claims 1-2, characterized in that: The control unit is connected to a connection node between the discharge tube and the charging tube, and controls the pre-discharge unit to be turned on or off based on a voltage at the connection node between the discharge tube and the charging tube.

4. The lithium battery protection module according to any one of claims 1-2, characterized in that: The control unit is connected to the positive electrode of the lithium battery, and when connected to an adapted charger, it notifies the charger to adjust the charging current based on the positive electrode voltage of the lithium battery.

5. A method for preventing a lithium battery interface from sparking, implemented based on the lithium battery protection module according to any one of claims 1 to 4, characterized in that: The lithium battery interface spark prevention method at least includes: When no external device is connected, the pre-discharge unit, discharge tube and charging tube are all in the off state; When a load is connected, determining whether the load is suitable; If not, the pre-discharge unit, the discharge tube and the charging tube are all kept in a closed state; If they are compatible, the pre-discharge unit and the charging tube are turned on, and the lithium battery supplies power to the load with a first discharge current; when the load is charged to a first preset voltage, the pre-discharge unit is turned off and the discharge tube is turned on, and the lithium battery supplies power to the load with a second discharge current; When a charger is connected, determining whether the charger is compatible; If not, the pre-discharge unit, the discharge tube and the charging tube are all kept in a closed state; If compatible, the discharge tube and the charging tube are turned on, and the charger is notified to charge the lithium battery with a first charging current; when the lithium battery is charged to a second preset voltage, the charger is notified to charge the lithium battery with a second charging current; The first discharging current is smaller than the second discharging current, and the first charging current is smaller than the second charging current.

6. The lithium battery interface spark prevention method according to claim 5, characterized in that: When no external device is connected, the lithium battery protection module is in sleep mode. When the load or the charger is connected, the lithium battery protection module is activated. If the load or the charger is not compatible, the lithium battery protection module switches back to sleep mode after a preset period of time.

7. The lithium battery interface spark prevention method according to claim 5, characterized in that: The first preset voltage is lower than the full charge voltage of the lithium battery, and the second preset voltage is lower than the full charge voltage of the lithium battery.

8. The lithium battery interface spark prevention method according to claim 5 or 7, characterized in that: Whether the load is charged to the first preset voltage is determined based on the voltage of the connection node between the discharge tube and the charging tube.

9. The lithium battery interface spark prevention method according to claim 5 or 7, characterized in that: Whether the lithium battery is charged to the second preset voltage is determined based on the positive electrode voltage of the lithium battery.

10. A lithium battery module, characterized in that: The lithium battery module at least comprises: A lithium battery and a lithium battery protection module as claimed in any one of claims 1 to 4; The positive electrode of the lithium battery serves as the positive electrode of the lithium battery module, and the negative electrode is connected to one end of the series structure of the discharge tube and the charging tube; the other end of the series structure of the discharge tube and the charging tube serves as the negative electrode of the lithium battery module.

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