A hybrid battery string

Abstract

The application discloses a battery pack with mixed batteries in series, and relates to the technical field of batteries. The battery pack comprises a power supply positive electrode end, a power supply negative electrode end, a master control device, a first battery pack and a second battery pack connected in series with the first battery pack. The first battery pack comprises a first charging and discharging switch circuit for turning on or turning off the negative electrode of the first battery pack and the positive electrode of the second battery pack, a first bypass switch circuit for turning on the positive electrode of the power supply and the positive electrode of the second battery pack, and a first voltage detection circuit for detecting the battery voltage of the first battery pack and outputting a corresponding first voltage detection signal. The master control device is used for controlling the first charging and discharging switch circuit to turn off the passage between the negative electrode of the first battery pack and the positive electrode of the second battery pack, and controlling the first bypass switch circuit to turn on the passage between the positive electrode of the power supply and the positive electrode of the second battery pack when the first voltage detection signal is greater than a first preset voltage. The application aims to realize synchronous charging of mixed batteries.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery pack consisting of hybrid batteries connected in series. Background Technology

[0002] Currently, BMS architectures combining lead-acid and lithium batteries in series are relatively rare in practical applications, mainly used in specific scenarios such as low-cost small-scale energy storage systems. The main challenge lies in the significant differences in charging characteristics between lead-acid and lithium batteries. Lead-acid batteries have different charging voltage ranges than lithium batteries, and lithium batteries are more sensitive to overcharging and over-discharging. Therefore, improper charging management can easily lead to overcharging of lithium batteries or undercharging of lead-acid batteries, affecting battery life and safety.

[0003] Existing technology involves modularizing the charger, separating the lead-acid battery charging module and the lithium battery charging module, and switching between the modules is achieved through a switch selection or automatic identification circuit. Summary of the Invention

[0004] The main objective of this invention is to provide a battery pack with hybrid batteries connected in series, which aims to achieve synchronous charging of the hybrid batteries.

[0005] To achieve the above objectives, the present invention proposes a hybrid battery pack connected in series, the battery pack comprising a positive power terminal, a negative power terminal, a main control device, a first battery pack, and a second battery pack connected in series with the first battery pack; The first battery pack includes a first charge / discharge switch circuit for turning on or off the negative terminal of the first battery pack and the positive terminal of the second battery pack, a first bypass switch circuit for turning on the positive terminal of the power supply and the positive terminal of the second battery pack, and a first voltage detection circuit for detecting the battery voltage of the first battery pack and outputting a corresponding first voltage detection signal. The main control device is electrically connected to the controlled terminal of the first charge / discharge switch circuit, the controlled terminal of the first bypass switch circuit, and the first voltage detection circuit, respectively. The main control device is used to control the first charge / discharge switch circuit to turn off the path between the negative terminal of the first battery pack and the positive terminal of the second battery pack when the first voltage detection signal is greater than a first preset voltage, and to control the first bypass switch circuit to turn on the path between the positive terminal of the power supply and the positive terminal of the second battery pack.

[0006] In one embodiment, the first charge / discharge switch circuit includes a first charge switch transistor and a first discharge switch transistor; Wherein, the first end of the first charging switch is electrically connected to the negative terminal of the first battery pack, the second end of the first charging switch is connected to the main control device, the third end of the first charging switch is electrically connected to the first end of the first discharging switch, the second end of the first charging switch is electrically connected to the main control device, and the third end of the first charging switch is electrically connected to the first bypass switch circuit and the positive terminal of the second battery pack.

[0007] In one embodiment, the first charging switch is a first charging NMOS transistor, and the first discharging switch is a first discharging NMOS transistor; The drain of the first charging NMOS transistor is electrically connected to the negative terminal of the first battery pack, the gate of the first charging NMOS transistor is electrically connected to the main control device, the source of the first charging NMOS transistor is electrically connected to the source of the first discharging NMOS transistor, the gate of the first charging NMOS transistor is electrically connected to the main control device, and the drain of the first charging NMOS transistor is electrically connected to the first bypass switch circuit and the positive terminal of the second battery pack.

[0008] In one embodiment, the number of first battery packs is N, and the N first battery packs are connected in series; the number of second battery packs is M, and the M second battery packs are connected in series. The first battery pack is a lithium battery pack; the second battery pack is a lead-acid battery pack.

[0009] In one embodiment, the battery pack with the hybrid batteries connected in series further includes a second voltage detection circuit, which is used to detect the voltage across the first charge / discharge switch circuit and output a second voltage detection signal to the main control device. The main control device is also used to control the first bypass switch circuit to open the path between the positive terminal of the power supply and the positive terminal of the second battery pack when the second voltage detection signal is greater than the second preset voltage.

[0010] The present invention also proposes a hybrid battery pack connected in series, the battery pack including a power supply positive terminal, a power supply negative terminal, a main control device, a first battery pack and a second battery pack connected in series with the first battery pack; The second battery pack includes a second charge / discharge switch circuit for turning on or off the negative terminal of the second battery pack and the negative terminal of the power supply, a second bypass switch circuit for turning on the negative terminal of the first battery pack and the negative terminal of the power supply, and a third voltage detection circuit for detecting the battery voltage of the second battery pack and outputting a corresponding third voltage detection signal. The main control device is electrically connected to the controlled terminal of the second charge / discharge switch circuit, the controlled terminal of the second bypass switch circuit, and the third voltage detection circuit, respectively. The main control device is used to control the second charge / discharge switch circuit to turn off the path between the negative terminal of the second battery pack and the negative terminal of the power supply when the third voltage detection signal is greater than the third preset voltage, and to control the second bypass switch circuit to turn on the path between the negative terminal of the first battery pack and the negative terminal of the power supply.

[0011] In one embodiment, the second charge / discharge switch circuit includes a second charging switch transistor and a second discharging switch transistor; Wherein, the first end of the second charging switch is electrically connected to the negative terminal of the second battery pack, the second end of the second charging switch is connected to the main control device, the third end of the second charging switch is electrically connected to the first end of the second discharging switch, the second end of the second charging switch is electrically connected to the main control device, and the third end of the second charging switch is electrically connected to the second bypass switch circuit and the negative terminal of the power supply.

[0012] In one embodiment, the second charging switch is a second charging NMOS transistor, and the second discharging switch is a second discharging NMOS transistor; The drain of the second charging NMOS transistor is electrically connected to the negative terminal of the second battery pack, the gate of the second charging NMOS transistor is electrically connected to the main control device, the source of the second charging NMOS transistor is electrically connected to the source of the second discharging NMOS transistor, the gate of the second charging NMOS transistor is electrically connected to the main control device, and the drain of the second charging NMOS transistor is electrically connected to the second bypass switch circuit and the negative terminal of the power supply.

[0013] In one embodiment, the number of first battery packs is N, and the N first battery packs are connected in series; the number of second battery packs is M, and the M second battery packs are connected in series. The first battery pack is a lead-acid battery pack; the second battery pack is a lithium battery pack.

[0014] In one embodiment, the battery pack with the hybrid batteries connected in series further includes a fourth voltage detection circuit, which is used to detect the voltage across the second charge / discharge switch circuit and output a fourth voltage detection signal to the main control device. The main control device is also used to control the second bypass switch circuit to open the path between the positive terminal of the power supply and the positive terminal of the second battery pack when the fourth voltage detection signal is greater than the fourth preset voltage.

[0015] This invention employs a hybrid battery pack connected in series, enabling stable synchronous charging of the hybrid batteries. The battery pack includes a positive power terminal, a negative power terminal, a main control device, a first battery pack, and a second battery pack connected in series with the first battery pack. The first and second battery packs are of two different types. Therefore, during synchronous charging of the first and second battery packs in series, one battery pack will be charged first, and it is necessary to ensure that while the charging circuit of the first battery pack is disconnected after charging, the charging circuit of the other battery pack, which is not yet fully charged, remains open. Therefore, by correspondingly configuring a first charge / discharge switch circuit, a first bypass switch circuit, and a first voltage detection circuit in the first battery pack, the main control device determines that the first battery pack is in a fully charged state based on the first voltage detection signal. It then shuts off the first charge / discharge switch circuit and turns on the first bypass switch circuit, allowing the battery pack that is not yet fully charged to charge. This method allows different types of battery packs to be charged synchronously, avoiding the problem of low charging efficiency caused by charging different types of battery packs separately. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the battery pack structure of the present invention, which uses a hybrid battery connected in series. Figure 2 This is a schematic diagram of a battery pack with hybrid batteries connected in series according to an embodiment of the present invention; Figure 3 This is a schematic diagram of another embodiment of the battery pack with hybrid batteries connected in series according to the present invention; Figure 4 This is a schematic diagram of another embodiment of the battery pack with hybrid batteries connected in series according to the present invention; Figure 5 This is a schematic diagram of another embodiment of the battery pack with hybrid batteries connected in series according to the present invention; Figure 6 This is a schematic diagram of another embodiment of the battery pack with hybrid batteries connected in series according to the present invention.

[0018] Explanation of icon numbers: 10. First battery pack; 11. First charge / discharge switch circuit; 12. First bypass switch circuit; 13. First voltage detection circuit; 20. Second battery pack; 21. Second charge / discharge switch circuit; 22. Second bypass switch circuit; 23. Third voltage detection circuit; 30. Second voltage detection circuit; 40. Fourth voltage detection circuit.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0023] Currently, BMS architectures combining lead-acid and lithium batteries in series are relatively rare in practical applications, mainly used in specific scenarios such as low-cost small-scale energy storage systems. The main challenge lies in the significant differences in charging characteristics between lead-acid and lithium batteries. Lead-acid batteries have different charging voltage ranges than lithium batteries, and lithium batteries are more sensitive to overcharging and over-discharging. Therefore, improper charging management can easily lead to overcharging of lithium batteries or undercharging of lead-acid batteries, affecting battery life and safety.

[0024] Existing technology involves modularizing the charger, separating the lead-acid battery charging module and the lithium battery charging module, and switching between the modules is achieved through a switch selection or automatic identification circuit.

[0025] To solve the above problems, refer to Figure 1 The present invention proposes a hybrid battery pack in series, the battery pack including a power supply positive terminal, a power supply negative terminal, a main control device, a first battery pack 10 and a second battery pack 20 connected in series with the first battery pack 10; The first battery pack 10 includes a first charge / discharge switch circuit 11 for turning on or off the negative terminal of the first battery pack 10 and the positive terminal of the second battery pack 20, a first bypass switch circuit 12 for turning on the positive terminal of the power supply and the positive terminal of the second battery pack 20, and a first voltage detection circuit 13 for detecting the battery voltage of the first battery pack 10 and outputting a corresponding first voltage detection signal. The main control device is electrically connected to the controlled terminal of the first charge / discharge switch circuit 11, the controlled terminal of the first bypass switch circuit 12, and the first voltage detection circuit 13, respectively. The main control device is used to control the first charge / discharge switch circuit 11 to shut off the path between the negative terminal of the first battery pack 10 and the positive terminal of the second battery pack 20 when the first voltage detection signal is greater than a first preset voltage, and to control the first bypass switch circuit 12 to open the path between the positive terminal of the power supply and the positive terminal of the second battery pack 20.

[0026] In this embodiment, the positive and negative terminals of the power supply are used to connect to the positive and negative terminals of the external charging power supply, respectively. The main control device can be implemented using a corresponding main controller, such as a DSP (Digital Signal Processor), MCU (Microcontroller Unit), FPGA (Field Programmable Gate Array), or SOC (System on Chip). The first battery pack 10 and the second battery pack 20 are two different types of battery packs, such as a lithium battery pack and a lead-acid battery pack, or a lithium battery pack and a lithium iron phosphate battery pack. It is understood that the charging termination conditions of the first battery pack 10 and the second battery pack 20 are different, which may result in one of the battery packs being charged first.

[0027] In this embodiment, the first battery pack 10 will be in a fully charged state preferentially compared to the second battery pack 20. Therefore, the first charge / discharge switch circuit 11, the first bypass switch circuit 12, and the first voltage detection circuit 13 are all disposed in the first battery pack 10. This allows the charging circuit of the first battery pack 10 to be shielded when it is in a fully charged state, and the first bypass switch circuit 12 to be turned on, so that the positive and negative terminals of the second battery pack 20 can be directly connected to the positive and negative terminals of the power supply, thereby enabling the charging of the second battery pack 20 without interfering with the first battery pack 10. The first charge / discharge switch circuit 11 and the first bypass switch circuit 12 can both be implemented using at least one switching transistor, such as a MOSFET, IGBT, thyristor, transistor, or power transistor, and / or using at least one switching device, such as a contactor, circuit breaker, or relay. Furthermore, the main control device can determine the charging state of the first battery pack 10 through the voltage detection signal output by the first voltage detection circuit 13. The first voltage detection circuit 13 can be implemented using a resistor voltage divider detection circuit, a Hall voltage detection circuit, etc., to detect the battery voltage of the first battery pack 10.

[0028] In this embodiment, the main control device is electrically connected to the controlled terminal of the first charge / discharge switch circuit 11, the controlled terminal of the first bypass switch circuit 12, and the first voltage detection circuit 13, respectively. This allows the main control device to control the first charge / discharge switch circuit 11 to turn off and the first bypass switch circuit 12 to turn on when the voltage value corresponding to the first voltage detection signal is greater than the first preset voltage. The first preset voltage can be set according to the type of the first battery pack 10 to ensure that the first battery pack 10 is in a fully charged state corresponding to the first preset voltage. When the first voltage detection signal is greater than the first preset voltage, i.e., the first battery pack 10 is in a fully charged state, the main control device first controls the first charge / discharge switch circuit 11 to turn off the path between the negative terminal of the first battery pack 10 and the positive terminal of the second battery pack 20, and then controls the first bypass switch circuit 12 to turn on the path between the positive terminal of the power supply and the positive terminal of the second battery pack 20. Through circuit structure and control method, the battery pack connected in series with the hybrid battery can stop charging the first battery pack 10 when the first battery pack 10 is in a fully charged state, and instead directly charge the second battery pack 20, thereby avoiding interference with the first battery pack 10.

[0029] By employing a hybrid battery pack connected in series, stable synchronous charging of the hybrid batteries can be achieved. The battery pack includes a positive power terminal, a negative power terminal, a main control device, a first battery pack 10, and a second battery pack 20 connected in series with the first battery pack 10. The first battery pack 10 and the second battery pack 20 are two different types of battery packs. Therefore, when the first battery pack 10 and the second battery pack 20 are charged synchronously in series, one of the battery packs will be charged first, and it is necessary to ensure that while the charging circuit of the first battery pack is disconnected after it is fully charged, the charging circuit of the other battery pack that is not fully charged remains open. Therefore, by correspondingly configuring a first charge / discharge switch circuit 11, a first bypass switch circuit 12, and a first voltage detection circuit 13 in the first battery pack 10, the main control device determines that the first battery pack 10 is in a fully charged state through the first voltage detection signal, thereby turning off the first charge / discharge switch circuit 11 and turning on the first bypass switch circuit 12 to allow the battery pack that is not in a fully charged state to charge. This method allows different types of battery packs to be charged simultaneously, avoiding the problem of low charging efficiency caused by charging different types of battery packs separately.

[0030] In one embodiment of the present invention, the first charge-discharge switch circuit 11 includes a first charge switch transistor and a first discharge switch transistor; Wherein, the first end of the first charging switch tube is electrically connected to the negative terminal of the first battery pack 10, the second end of the first charging switch tube is connected to the main control device, the third end of the first charging switch tube is electrically connected to the first end of the first discharging switch tube, the second end of the first charging switch tube is electrically connected to the main control device, and the third end of the first charging switch tube is electrically connected to the positive terminal of the first bypass switch circuit 12 and the second battery pack 20.

[0031] It is understandable that when the voltage of a lithium battery exceeds 4.25V, the positive electrode material decomposes to release oxygen, the electrolyte decomposes to produce gas, and a thermal runaway chain reaction may trigger a fire or explosion within seconds. Therefore, when the first battery pack 10 is a lithium battery pack or other battery packs with poor stability, it is necessary to avoid the first battery pack 10 being overcharged. In this embodiment, the first charge / discharge switch circuit 11 includes a first charging switch transistor and a first discharging switch transistor to ensure that the first charge / discharge switch circuit 11 can stably achieve the shutdown of the charging circuit of the first battery pack 10. It is understandable that the first charge / discharge switch transistor 11 is located on the negative electrode side of the first battery pack 10, the purpose of which is to bring the potential on the first charge / discharge switch circuit 11 side close to ground, thereby greatly simplifying the drive circuit. The first charging switch transistor and the first discharging switch transistor can be selected and set according to actual needs.

[0032] Optionally, the first charging switch is a first charging NMOS transistor, and the first discharging switch is a first discharging NMOS transistor; The drain of the first charging NMOS transistor is electrically connected to the negative terminal of the first battery pack 10, the gate of the first charging NMOS transistor is electrically connected to the main control device, the source of the first charging NMOS transistor is electrically connected to the source of the first discharging NMOS transistor, the gate of the first charging NMOS transistor is electrically connected to the main control device, and the drain of the first charging NMOS transistor is electrically connected to the positive terminal of the first bypass switch circuit 12 and the second battery pack 20.

[0033] Understandably, NMOS transistors have lower on-resistance, which means less heat generation, higher efficiency, and are better suited for applications like battery packs that are extremely sensitive to temperature rise.

[0034] In addition, the first bypass switch circuit 12 can also be implemented using an NMOS transistor.

[0035] refer to Figure 2 In one embodiment of the present invention, the number of the first battery pack 10 is N, and the N first battery packs 10 are connected in series; the number of the second battery pack 20 is M, and the M second battery packs 20 are connected in series. The first battery pack 10 is a lithium battery pack; the second battery pack 20 is a lead-acid battery pack.

[0036] In this embodiment, N and M are both positive integers greater than or equal to 1. N and M can be equal or unequal. The number of first battery packs 10 and the number of second battery packs 20 can be different; that is, the hybrid battery pack in series includes multiple sets of first battery packs 10 and multiple sets of second battery packs 20 connected in series. These multiple sets of first battery packs 10 and multiple sets of second battery packs 20 are connected in series to increase the battery capacity of the hybrid battery pack. Furthermore, the first battery pack 10 is a lithium battery pack, and the second battery pack 20 is a lead-acid battery pack. It is understood that the lithium battery pack can handle high-efficiency, long-life daily operation, while the lead-acid battery pack can handle low-cost, high-capacity battery storage. The two achieve seamless cooperation through differences in charging termination conditions and bypass mechanisms, eliminating the need for complex power electronic converters and fully leveraging the advantages of each type of battery.

[0037] refer to Figure 3 In one embodiment of the present invention, the battery pack of the hybrid batteries connected in series further includes a second voltage detection circuit 30, which is used to detect the voltage across the first charge-discharge switch circuit 11 and output a second voltage detection signal to the main control device. The main control device is also used to control the first bypass switch circuit 12 to open the path between the positive terminal of the power supply and the positive terminal of the second battery pack 20 when the second voltage detection signal is greater than the second preset voltage.

[0038] In this embodiment, the second voltage detection circuit 30 can be implemented using a resistor voltage divider detection circuit, a Hall voltage detection circuit, or the like. The second voltage detection circuit 30 is used to detect the voltage across the first charge / discharge switch circuit 11. It is understood that to prevent charging failures in the first battery pack 10 and the second battery pack 20, it is necessary to ensure that the first battery pack 10 is in a fully charged state before first shutting off the first charge / discharge switch circuit 11 and then turning on the first bypass switch circuit 12. Therefore, by detecting the voltage across the first charge / discharge switch circuit 11, it can be confirmed whether the first charge / discharge switch circuit 11 is in a turned-off state, and then the first bypass switch circuit 12 can be turned on, thereby preventing a short circuit in the first battery pack 10. The second preset voltage can be derived from the voltage value across the first charge / discharge switch circuit 11 when it is in a turned-off state.

[0039] refer to Figure 4 The present invention also proposes a battery pack with batteries connected in series, the battery pack including a power supply positive terminal, a power supply negative terminal, a main control device, a first battery pack 10 and a second battery pack 20 connected in series with the first battery pack 10; The second battery pack 20 includes a second charge / discharge switch circuit 21 for turning on or off the negative terminal of the second battery pack 20 and the negative terminal of the power supply, a second bypass switch circuit 22 for turning on the negative terminal of the first battery pack 10 and the negative terminal of the power supply, and a third voltage detection circuit 23 for detecting the battery voltage of the second battery pack 20 and outputting a corresponding third voltage detection signal. The main control device is electrically connected to the controlled terminal of the second charge / discharge switch circuit 21, the controlled terminal of the second bypass switch circuit 22, and the third voltage detection circuit 23, respectively. The main control device is used to control the second charge / discharge switch circuit 21 to turn off the path between the negative terminal of the second battery pack 20 and the negative terminal of the power supply when the third voltage detection signal is greater than the third preset voltage, and to control the second bypass switch circuit 22 to open the path between the negative terminal of the first battery pack 10 and the negative terminal of the power supply.

[0040] It is understood that the difference from the above embodiment lies in the placement of the second charge / discharge switch circuit 21, the second bypass switch circuit 22, and the third voltage detection circuit 23. In other words, the battery characteristics of the first battery pack 10 and the second battery pack 20 are opposite to those in the above embodiment. Therefore, in this embodiment, the discharge switch circuit, the second bypass switch circuit 22, and the third voltage detection circuit 23 are located in the second battery pack 20, meaning the second battery pack 20 is a battery pack with low overvoltage tolerance, such as a lithium battery pack. In practical applications, the second battery pack 20 will be charged preferentially. At this time, the main control device will control the second charge / discharge switch circuit 21 to shut off the path between the negative terminal of the second battery pack 20 and the negative terminal of the power supply, and control the second bypass switch circuit 22 to open the path between the negative terminal of the first battery pack 10 and the negative terminal of the power supply, so as to achieve the simultaneous opening and maintenance of the charging circuit of the first battery pack 10 while shutting off the charging circuit of the second battery pack 20.

[0041] In this embodiment, the positive and negative terminals of the power supply are used to connect to the positive and negative terminals of the external charging power supply, respectively. The main control device can be implemented using a corresponding main controller, such as a DSP (Digital Signal Processor), MCU (Microcontroller Unit), FPGA (Field Programmable Gate Array), or SOC (System on Chip). The first battery pack 10 and the second battery pack 20 are two different types of battery packs, such as a lithium battery pack and a lead-acid battery pack, or a lithium battery pack and a lithium iron phosphate battery pack. It is understood that the charging termination conditions of the first battery pack 10 and the second battery pack 20 are different, which may result in one of the battery packs being charged first.

[0042] In this embodiment, the second battery pack 20 will be in a fully charged state preferentially compared to the first battery pack 10. Therefore, the second charge / discharge switch circuit 21, the second bypass switch circuit 22, and the third voltage detection circuit 23 are all located in the second battery pack 20. This allows the charging circuit of the second battery pack 20 to be shielded when it is in a fully charged state, and the second bypass switch circuit 22 to be turned on, so that the positive and negative terminals of the first battery pack 10 can be directly connected to the positive and negative terminals of the power supply, thereby enabling the charging of the first battery pack 10 without interfering with the second battery pack 20. The second charge / discharge switch circuit 21 and the second bypass switch circuit 22 can both be implemented using at least one switching transistor, such as a MOSFET, IGBT, thyristor, transistor, or power transistor, and / or using at least one switching device, such as a contactor, circuit breaker, or relay. Furthermore, the main control device can determine the charging state of the second battery pack 20 through the voltage detection signal output by the third voltage detection circuit 23. The third voltage detection circuit 23 can be implemented using a resistor voltage divider detection circuit, a Hall voltage detection circuit, etc., to detect the battery voltage of the second battery pack 20.

[0043] In this embodiment, the main control device is electrically connected to the controlled terminal of the second charge / discharge switch circuit 21, the controlled terminal of the second bypass switch circuit 22, and the third voltage detection circuit 23, respectively. This allows the main control device to control the second charge / discharge switch circuit 21 to turn off and the second bypass switch circuit 22 to turn on when the voltage value corresponding to the third voltage detection signal is greater than the third preset voltage. The third preset voltage can be set according to the type of the second battery pack 20 to ensure that the second battery pack 20 is in a fully charged state corresponding to the third preset voltage. When the third voltage detection signal is greater than the third preset voltage, i.e., the second battery pack 20 is in a fully charged state, the main control device will first control the second charge / discharge switch circuit 21 to turn off the path between the negative terminal of the second battery pack 20 and the negative terminal of the power supply, and then control the second bypass switch circuit 22 to turn on the path between the negative terminal of the second battery pack 20 and the negative terminal of the power supply. Through the circuit structure and control method, the battery pack connected in series with the hybrid battery can be charged directly to the first battery pack 10 when the second battery pack 20 is in a fully charged state, thereby avoiding interference with the second battery pack 20.

[0044] By employing a hybrid battery pack connected in series, stable synchronous charging of the hybrid batteries can be achieved. The battery pack includes a positive power terminal, a negative power terminal, a main control device, a first battery pack 10, and a second battery pack 20 connected in series with the first battery pack 10. The first battery pack 10 and the second battery pack 20 are two different types of battery packs. Therefore, when the first battery pack 10 and the second battery pack 20 are charged synchronously in series, one of the battery packs will be charged first, and it is necessary to ensure that while the charging circuit of the first battery pack is disconnected after being fully charged, the charging circuit of the other battery pack that is not fully charged remains open. Therefore, by correspondingly configuring a second charge / discharge switch circuit 21, a second bypass switch circuit 22, and a third voltage detection circuit 23 in the second battery pack 20, the main control device determines that the second battery pack 20 is in a fully charged state through the third voltage detection signal, thereby turning off the second charge / discharge switch circuit 21 and turning on the second bypass switch circuit 22 to allow the battery pack that is not in a fully charged state to charge. This method allows different types of battery packs to be charged simultaneously, avoiding the problem of low charging efficiency caused by charging different types of battery packs separately.

[0045] Optionally, the second charge / discharge switch circuit 21 includes a second charge switch transistor and a second discharge switch transistor; Wherein, the first end of the second charging switch is electrically connected to the negative terminal of the second battery pack 20, the second end of the second charging switch is connected to the main control device, the third end of the second charging switch is electrically connected to the first end of the second discharging switch, the second end of the second charging switch is electrically connected to the main control device, and the third end of the second charging switch is electrically connected to the second bypass switch circuit 22 and the negative terminal of the power supply.

[0046] Optionally, the second charging switch is a second charging NMOS transistor, and the second discharging switch is a second discharging NMOS transistor; The drain of the second charging NMOS transistor is electrically connected to the negative terminal of the second battery pack 20, the gate of the second charging NMOS transistor is electrically connected to the main control device, the source of the second charging NMOS transistor is electrically connected to the source of the second discharging NMOS transistor, the gate of the second charging NMOS transistor is electrically connected to the main control device, and the drain of the second charging NMOS transistor is electrically connected to the second bypass switch circuit 22 and the negative terminal of the power supply.

[0047] refer to Figure 5 Optionally, the number of the first battery pack 10 is N, and the N first battery packs 10 are connected in series; the number of the second battery pack 20 is M, and the M second battery packs 20 are connected in series. The first battery pack 10 is a lead-acid battery pack; the second battery pack 20 is a lithium battery pack.

[0048] refer to Figure 6 Optionally, the battery pack with the hybrid batteries connected in series further includes a fourth voltage detection circuit 40, which is used to detect the voltage across the second charge / discharge switch circuit 21 and output a fourth voltage detection signal to the main control device. The main control device is also used to control the second bypass switch circuit 22 to open the path between the positive terminal of the power supply and the positive terminal of the second battery pack 20 when the fourth voltage detection signal is greater than the fourth preset voltage.

[0049] The same principle applies to the above embodiments.

[0050] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A battery pack with hybrid batteries connected in series, characterized in that, The battery pack includes a positive power terminal, a negative power terminal, a main control device, a first battery pack, and a second battery pack connected in series with the first battery pack. The first battery pack includes a first charge / discharge switch circuit for turning on or off the negative terminal of the first battery pack and the positive terminal of the second battery pack, a first bypass switch circuit for turning on the positive terminal of the power supply and the positive terminal of the second battery pack, and a first voltage detection circuit for detecting the battery voltage of the first battery pack and outputting a corresponding first voltage detection signal. The main control device is electrically connected to the controlled terminal of the first charge / discharge switch circuit, the controlled terminal of the first bypass switch circuit, and the first voltage detection circuit, respectively. The main control device is used to control the first charge / discharge switch circuit to turn off the path between the negative terminal of the first battery pack and the positive terminal of the second battery pack when the first voltage detection signal is greater than the first preset voltage, and to control the first bypass switch circuit to turn on the path between the positive terminal of the power supply and the positive terminal of the second battery pack.

2. The battery pack with hybrid batteries connected in series as described in claim 1, characterized in that, The first charge / discharge switch circuit includes a first charging switch transistor and a first discharging switch transistor; Wherein, the first end of the first charging switch is electrically connected to the negative terminal of the first battery pack, the second end of the first charging switch is connected to the main control device, the third end of the first charging switch is electrically connected to the first end of the first discharging switch, the second end of the first charging switch is electrically connected to the main control device, and the third end of the first charging switch is electrically connected to the first bypass switch circuit and the positive terminal of the second battery pack.

3. The battery pack with hybrid batteries connected in series as described in claim 2, characterized in that, The first charging switch is a first charging NMOS transistor, and the first discharging switch is a first discharging NMOS transistor; The drain of the first charging NMOS transistor is electrically connected to the negative terminal of the first battery pack, the gate of the first charging NMOS transistor is electrically connected to the main control device, the source of the first charging NMOS transistor is electrically connected to the source of the first discharging NMOS transistor, the gate of the first charging NMOS transistor is electrically connected to the main control device, and the drain of the first charging NMOS transistor is electrically connected to the first bypass switch circuit and the positive terminal of the second battery pack.

4. The battery pack with hybrid batteries connected in series as described in any one of claims 1 to 3, characterized in that, The number of the first battery packs is N, and the N first battery packs are connected in series; the number of the second battery packs is M, and the M second battery packs are connected in series. The first battery pack is a lithium battery pack; the second battery pack is a lead-acid battery pack.

5. The battery pack with hybrid batteries connected in series as described in any one of claims 1 to 3, characterized in that, The battery pack with the hybrid batteries connected in series also includes a second voltage detection circuit. The second voltage detection circuit is used to detect the voltage across the first charge / discharge switch circuit and output a second voltage detection signal to the main control device. The main control device is also used to control the first bypass switch circuit to open the path between the positive terminal of the power supply and the positive terminal of the second battery pack when the second voltage detection signal is greater than the second preset voltage.

6. A battery pack with hybrid batteries connected in series, characterized in that, The battery pack includes a positive power terminal, a negative power terminal, a main control device, a first battery pack, and a second battery pack connected in series with the first battery pack. The second battery pack includes a second charge / discharge switch circuit for turning on or off the negative terminal of the second battery pack and the negative terminal of the power supply, a second bypass switch circuit for turning on the negative terminal of the first battery pack and the negative terminal of the power supply, and a third voltage detection circuit for detecting the battery voltage of the second battery pack and outputting a corresponding third voltage detection signal. The main control device is electrically connected to the controlled terminal of the second charge / discharge switch circuit, the controlled terminal of the second bypass switch circuit, and the third voltage detection circuit, respectively. The main control device is used to control the second charge / discharge switch circuit to turn off the path between the negative terminal of the second battery pack and the negative terminal of the power supply when the third voltage detection signal is greater than the third preset voltage, and to control the second bypass switch circuit to turn on the path between the negative terminal of the first battery pack and the negative terminal of the power supply.

7. The battery pack with hybrid batteries connected in series as described in claim 1, characterized in that, The second charge / discharge switch circuit includes a second charging switch transistor and a second discharging switch transistor; Wherein, the first end of the second charging switch is electrically connected to the negative terminal of the second battery pack, the second end of the second charging switch is connected to the main control device, the third end of the second charging switch is electrically connected to the first end of the second discharging switch, the second end of the second charging switch is electrically connected to the main control device, and the third end of the second charging switch is electrically connected to the second bypass switch circuit and the negative terminal of the power supply.

8. The battery pack with hybrid batteries connected in series as described in claim 7, characterized in that, The second charging switch is a second charging NMOS transistor, and the second discharging switch is a second discharging NMOS transistor; The drain of the second charging NMOS transistor is electrically connected to the negative terminal of the second battery pack, the gate of the second charging NMOS transistor is electrically connected to the main control device, the source of the second charging NMOS transistor is electrically connected to the source of the second discharging NMOS transistor, the gate of the second charging NMOS transistor is electrically connected to the main control device, and the drain of the second charging NMOS transistor is electrically connected to the second bypass switch circuit and the negative terminal of the power supply.

9. The battery pack with hybrid batteries connected in series as described in any one of claims 6 to 8, characterized in that, The number of the first battery packs is N, and the N first battery packs are connected in series; the number of the second battery packs is M, and the M second battery packs are connected in series. The first battery pack is a lead-acid battery pack; the second battery pack is a lithium battery pack.

10. The battery pack with hybrid batteries connected in series as described in any one of claims 6 to 8, characterized in that, The battery pack with the hybrid batteries connected in series also includes a fourth voltage detection circuit, which is used to detect the voltage across the two ends of the second charge / discharge switch circuit and output a fourth voltage detection signal to the main control device. The main control device is also used to control the second bypass switch circuit to open the path between the positive terminal of the power supply and the positive terminal of the second battery pack when the fourth voltage detection signal is greater than the fourth preset voltage.

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