Battery under-voltage prompt circuit and battery management system

Abstract

The utility model provides a battery under-voltage prompt circuit, comprising a power supply sub-circuit, the input end of which is used for being connected with a battery; the input end of the potential inversion sub-circuit is connected with the output end of the power supply sub-circuit; the input end of the driving sub-circuit is connected with the output end of the potential inversion sub-circuit; and the input end of the acousto-optic prompting sub-circuit is connected with the output end of the driving sub-circuit. When the BMS based on the lithium battery is in a closed state and the lithium battery enters an under-voltage state, under-voltage information is prompted to a user in a sound and light mode, so that the user knows that the lithium battery is in the under-voltage state and charges the lithium battery in time, and the lithium battery is prevented from being damaged due to long-term under-voltage.

Description

Technical Field

[0001] The utility model relates to the technical field of battery management, and more specifically to a battery undervoltage prompting circuit and a battery management system. Background Art

[0002] At present, lithium batteries have entered thousands of households, and their application scenarios include: electric vehicles, energy storage, power tools, etc. However, a major defect of lithium batteries is that they cannot be in an undervoltage state for a long time. Lithium batteries that are in an undervoltage state for a long time will suffer irreversible damage. Therefore, lithium batteries need to be protected from undervoltage during use. However, undervoltage protection only turns off the peripheral loads of lithium batteries. In fact, lithium batteries also have their own energy consumption. That is to say, after all the peripheral loads of lithium batteries are removed, the lithium battery will continue to discharge the stored energy due to the internal self-consumption of lithium batteries. Therefore, in reality, lithium batteries that are not replenished (charged) for a long time will be damaged due to self-consumption of electricity; existing lithium battery products may have information prompt functions for undervoltage, but all undervoltage information prompt functions are based on the lithium battery management system (BMS) being in normal opening (activated state). When the BMS itself is turned off (inactive state), the BMS no longer has the ability to transmit undervoltage information to the outside. After the BMS is turned off, the lithium battery may enter an undervoltage state due to factors such as the self-consumption of lithium batteries. When the lithium battery is undervoltage when the BMS is turned off, the undervoltage information cannot be transmitted to the user, resulting in the user not knowing that the lithium battery is actually in an undervoltage state, and then not replenishing (charging) the undervoltage lithium battery, which eventually causes the lithium battery to be in an undervoltage state for a long time until the lithium battery is damaged. Utility Model Content

[0003] This specification provides a battery undervoltage warning circuit. When the BMS of a lithium battery is in a closed state, when the lithium battery enters an undervoltage state, the undervoltage information is prompted to the user by sound and light, so that the user knows that the lithium battery is in an undervoltage state and can replenish (charge) the lithium battery in time, thereby avoiding damage to the lithium battery due to long-term undervoltage.

[0004] The embodiment of this specification discloses a battery undervoltage warning circuit, including:

[0005] A power supply circuit, the input end of which is used to connect to a battery;

[0006] a potential reversal subcircuit, the input end of which is connected to the output end of the power supply subcircuit;

[0007] a driving subcircuit, whose input terminal is connected to the output terminal of the potential reversal subcircuit;

[0008] The sound and light prompt sub-circuit has an input end connected to the output end of the driving sub-circuit.

[0009] In some embodiments of the present specification, the operating current of the power supply circuit is uA level current.

[0010] In some embodiments of the present specification, the power supply circuit is a circuit composed of one or more combinations of a linear regulator, a field effect transistor, a triode, a voltage regulator and a resistor.

[0011] In some embodiments of the present specification, the power supply circuit is composed of a linear regulator U1 and a resistor R1 connected in series.

[0012] In some embodiments of the present specification, the power supply circuit is independently composed of a resistor R1.

[0013] In some embodiments of the present specification, the power supply circuit is composed of a voltage regulator tube Z1 and a resistor R1 connected in series.

[0014] In some embodiments of the present specification, the potential reversal sub-circuit includes a resistor R2 and a field effect transistor Q1, one end of the resistor R2 is connected to the gate of the field effect transistor Q1 and the output end of the power supply sub-circuit, the other end of the resistor R2 is connected to the source of the field effect transistor Q1 and then grounded, and the drain of the field effect transistor Q1 is connected to the input end of the driving sub-circuit.

[0015] In some embodiments of the present specification, the driving subcircuit includes a resistor R3, a resistor R4, a resistor R5, a resistor R6 and a field effect transistor Q2, one end of the resistor R3 is connected to one end of the resistor R4, one end of the resistor R6 and the output end of the potential reversal subcircuit, the other end of the resistor R4 is grounded, the other end of the resistor R6 is connected to the gate of the field effect transistor Q2, the source of the field effect transistor Q2 is connected to the input end of the sound and light prompt subcircuit, the other end of the resistor R3 is connected to one end of the resistor R5 and then connected to the external voltage terminal BAT+, and the other end of the resistor R5 is connected to the drain of the field effect transistor Q2.

[0016] In some embodiments of the present specification, the sound and light prompt sub-circuit includes a resistor R7, a field effect transistor Q3 and an sound and light device F1, one end of the resistor R7 is connected to the gate of the field effect transistor Q3 and the output end of the driving sub-circuit, the other end of the resistor R7 is connected to the source of the field effect transistor Q3 and then grounded, the drain of the field effect transistor Q3 is connected to one end of the sound and light device F1, and the other end of the sound and light device F1 is connected to the external voltage terminal BAT+.

[0017] The embodiment of this specification also discloses a battery management system, including any one of the above-mentioned battery undervoltage prompt circuits.

[0018] This manual can at least achieve the following beneficial effects:

[0019] The battery undervoltage warning circuit can be based on the fact that the BMS of the lithium battery itself is in a closed state. When the lithium battery enters an undervoltage state, the undervoltage information is prompted to the user through sound and light, so that the user knows that the lithium battery is in an undervoltage state and replenishes (charges) the lithium battery in time, thereby avoiding damage to the lithium battery due to long-term undervoltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a battery undervoltage warning circuit involved in some embodiments of the utility model.

[0021] Figure 2 Schematic diagram of a circuit in which a power supply sub-circuit according to some other embodiments of the present invention is independently composed of a resistor R1.

[0022] Figure 3 The schematic diagram of the power supply circuit according to some embodiments of the present invention is a circuit diagram consisting of a voltage regulator tube Z1 and a resistor R1 connected in series. DETAILED DESCRIPTION

[0023] The technical solution of the present utility model is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present utility model is not limited to the following.

[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0025] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present utility model, unless otherwise clearly specified and limited, if a first feature exists above or below a second feature, it may include that the first and second features are in direct contact, or it may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is above, above and above the second feature, including that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. If a first feature exists below, below and below the second feature, it includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] The present invention is further described below in conjunction with the embodiments, which are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by ordinary technicians in the field without creative work are all within the protection scope of the present invention.

[0029] Please refer to the attached drawings, which show the structure of the embodiment selected for the present invention, which is for illustration only, and the patent application is not limited to this structure.

[0030] The embodiment of this specification discloses a battery undervoltage warning circuit, including:

[0031] A power supply circuit, the input end of which is used to connect to a battery;

[0032] a potential reversal subcircuit, the input end of which is connected to the output end of the power supply subcircuit;

[0033] a driving subcircuit, whose input terminal is connected to the output terminal of the potential reversal subcircuit;

[0034] The sound and light prompt sub-circuit has an input end connected to the output end of the driving sub-circuit.

[0035] In some embodiments, the operating current of the power supply circuit is uA level current.

[0036] In some embodiments, the power supply circuit is a circuit composed of one or more combinations of a linear regulator, a field effect transistor, a triode, a voltage regulator and a resistor.

[0037] In some embodiments, Figure 1 As shown, the power supply circuit is composed of a linear regulator U1 and a resistor R1 connected in series.

[0038] In some embodiments, Figure 2 As shown, the power supply circuit is independently composed of a resistor R1.

[0039] In some embodiments, Figure 3 As shown, the power supply circuit is composed of a voltage regulator tube Z1 and a resistor R1 connected in series.

[0040] In some embodiments, the potential reversal sub-circuit includes a resistor R2 and a field effect transistor Q1, one end of the resistor R2 is connected to the gate of the field effect transistor Q1 and the output end of the power supply sub-circuit, the other end of the resistor R2 is connected to the source of the field effect transistor Q1 and then grounded, and the drain of the field effect transistor Q1 is connected to the input end of the driving sub-circuit.

[0041] In some embodiments, the driving subcircuit includes a resistor R3, a resistor R4, a resistor R5, a resistor R6 and a field effect transistor Q2, one end of the resistor R3 is connected to one end of the resistor R4, one end of the resistor R6 and the output end of the potential reversal subcircuit, the other end of the resistor R4 is grounded, the other end of the resistor R6 is connected to the gate of the field effect transistor Q2, the source of the field effect transistor Q2 is connected to the input end of the sound and light prompt subcircuit, the other end of the resistor R3 is connected to one end of the resistor R5 and then connected to the external voltage terminal BAT+, and the other end of the resistor R5 is connected to the drain of the field effect transistor Q2.

[0042] In some embodiments, the sound and light prompt sub-circuit includes a resistor R7, a field effect transistor Q3 and an sound and light device F1, one end of the resistor R7 is connected to the gate of the field effect transistor Q3 and the output end of the driving sub-circuit, the other end of the resistor R7 is connected to the source of the field effect transistor Q3 and then grounded, the drain of the field effect transistor Q3 is connected to one end of the sound and light device F1, and the other end of the sound and light device F1 is connected to the external voltage terminal BAT+.

[0043] In summary, the working principle is as follows:

[0044] By properly selecting devices or adjusting parameters, the working current of the power supply circuit can reach uA level, which is a low-power power supply circuit; the power supply circuit is in working state for a long time, regardless of whether the BMS is in the off state. When the battery is in an undervoltage state, the power supply circuit will stop outputting (i.e.: the output voltage of the power supply circuit ≈ 0V). Since the power supply circuit has no voltage output, the field effect tube Q1 of the potential reversal subcircuit will be in a non-conducting state, so that the drain of the field effect tube Q1 is at a high level. The drain of the field effect tube Q1 is at a high level, which will cause the field effect tube Q2 of the driving subcircuit to turn on. The conduction of the field effect tube Q2 will cause the field effect tube Q3 of the sound and light prompt subcircuit to turn on. After the field effect tube Q3 is turned on, the sound and light device F1 has current flowing through it and emits sound and light, thereby achieving the purpose of prompting the user when undervoltage occurs.

[0045] On the contrary, when the battery is not under-voltage, since the power supply sub-circuit has voltage output, the field effect transistor Q1 of the potential reversal sub-circuit is turned on, causing the field effect transistor Q2 of the driving sub-circuit to be turned off, thereby causing the field effect transistor Q3 of the sound and light prompt sub-circuit to be turned off, and the sound and light device F1 has no current flowing through it and will not emit sound or light.

[0046] The sound and light device F1 can be a buzzer and an LED indicator light to realize the function of sound and light warning.

[0047] The embodiment of this specification also discloses a battery management system, including any one of the above-mentioned battery undervoltage prompt circuits.

[0048] The above embodiments are used to illustrate the present invention, not to limit the present invention, so changes in the exemplified values ​​or replacement of equivalent components should still fall within the scope of the present invention.

[0049] From the above detailed description, it can be understood by those skilled in the art that the present invention can indeed achieve the aforementioned objectives and is in compliance with the provisions of the Patent Law.

[0050] Although the preferred embodiments of the utility model have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the utility model. The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. It should be pointed out that any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. A battery undervoltage warning circuit, characterized in that: include: A power supply circuit, the input end of which is used to connect to a battery; a potential reversal subcircuit, the input end of which is connected to the output end of the power supply subcircuit; a driving subcircuit, whose input terminal is connected to the output terminal of the potential reversal subcircuit; The sound and light prompt sub-circuit has an input end connected to the output end of the driving sub-circuit.

2. The battery undervoltage warning circuit according to claim 1, characterized in that: The working current of the power supply circuit is uA level current.

3. The battery undervoltage warning circuit according to claim 1, characterized in that: The power supply circuit is composed of a linear regulator U1 and a resistor R1 connected in series.

4. The battery undervoltage warning circuit according to claim 1, characterized in that: The power supply subcircuit is independently composed of a resistor R1.

5. The battery undervoltage warning circuit according to claim 1, characterized in that: The power supply circuit is composed of a voltage regulator tube Z1 and a resistor R1 connected in series.

6. The battery undervoltage warning circuit according to claim 1, characterized in that: The potential reversal subcircuit includes a resistor R2 and a field effect transistor Q1, one end of the resistor R2 is connected to the gate of the field effect transistor Q1 and the output end of the power supply subcircuit, the other end of the resistor R2 is connected to the source of the field effect transistor Q1 and then grounded, and the drain of the field effect transistor Q1 is connected to the input end of the driving subcircuit.

7. The battery undervoltage warning circuit according to claim 1, characterized in that: The driving subcircuit includes a resistor R3, a resistor R4, a resistor R5, a resistor R6 and a field effect transistor Q2, one end of the resistor R3 is connected to one end of the resistor R4, one end of the resistor R6 and the output end of the potential reversal subcircuit, the other end of the resistor R4 is grounded, the other end of the resistor R6 is connected to the gate of the field effect transistor Q2, the source of the field effect transistor Q2 is connected to the input end of the sound and light prompt subcircuit, the other end of the resistor R3 is connected to one end of the resistor R5 and then connected to the external voltage terminal BAT+, and the other end of the resistor R5 is connected to the drain of the field effect transistor Q2.

8. The battery undervoltage warning circuit according to claim 1, characterized in that: The sound and light prompt sub-circuit includes a resistor R7, a field effect transistor Q3 and an sound and light device F1, one end of the resistor R7 is connected to the gate of the field effect transistor Q3 and the output end of the driving sub-circuit, the other end of the resistor R7 is connected to the source of the field effect transistor Q3 and then grounded, the drain of the field effect transistor Q3 is connected to one end of the sound and light device F1, and the other end of the sound and light device F1 is externally connected to the voltage terminal BAT+.

9. A battery management system, characterized in that: The invention comprises the battery undervoltage warning circuit according to any one of claims 1 to 8.

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