Tandem type lithium battery protection board

Abstract

The utility model relates to a tandem lithium battery protection plate which comprises a protection plate body which is used for protecting a battery pack consisting of a plurality of battery units, the protection plate body comprises a management unit, a voltage acquisition end of the management unit performs voltage acquisition on a plurality of battery units, a current acquisition end of the management unit performs current acquisition on a battery pack, and a discharge control end of the management unit is electrically connected with a discharge control circuit. The charging control end of the management unit is electrically connected with an anti-backflow circuit, and the load / charger detection port of the management unit is electrically connected with a load / charger detection clamping circuit. According to the utility model, charging MOS tube driving protection is carried out through the anti-backflow circuit, a load / charger detection port of the management unit is effectively protected through the load / charger detection clamping circuit, troubleshooting is simple, and the maintenance cost is low; and the cubic lithium battery pack units can be flexibly connected in series to meet vehicle types with different voltage grades.

Description

Technical Field

[0001] This utility model relates to the field of lithium batteries, and in particular to a series-connectable lithium battery protection board. Background Technology

[0002] Currently, the lithium battery field typically uses integrated lithium battery packs, which have poor size compatibility, are difficult to maintain, and the protection boards do not support series connection; specifically:

[0003] 1. Currently, power lithium battery packs cannot be flexibly connected in series, which means that the battery compartments of most electric motorcycles and lightweight electric motorcycles cannot be matched with the integrated lithium battery packs on the market. The installation size is limited, which leads to many small workshops without formal production qualifications engaging in illegal customization and modification, increasing the risk of use.

[0004] 2. Lithium battery manufacturers need to adapt to different vehicle sizes, requiring them to design and manufacture battery packs of various sizes and styles to meet usage requirements. This makes it impossible to standardize the production of lithium battery packs like lead-acid batteries, resulting in inconsistent quality.

[0005] 3. Maintaining an integrated lithium battery is quite difficult, requiring complete disassembly and repair at the factory, resulting in high maintenance costs, long maintenance cycles, and significant diagnostic challenges.

[0006] 4. Currently, protection boards on the market cannot support series use. Firstly, the charging and discharging MOSFETs have low voltage tolerance, and secondly, there are no relevant isolation and protection circuits for this solution, which means they can only be used in integrated batteries. Utility Model Content

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a series-connectable lithium battery protection board that is easy to troubleshoot and has low maintenance costs; it also allows the "cubic lithium battery pack" units to be flexibly connected in series to meet the needs of different voltage levels in vehicle models.

[0008] The objective of this utility model is achieved through the following technical solution:

[0009] A series-connectable lithium battery protection board includes a protection board body that protects a battery pack composed of multiple battery cells. The protection board body includes a management unit. The voltage acquisition terminal of the management unit acquires the voltage of the multiple battery cells, the current acquisition terminal of the management unit acquires the current of the battery pack, the discharge control terminal of the management unit is electrically connected to a discharge control circuit, the charging control terminal of the management unit is electrically connected to an anti-reverse current circuit, and the load / charger detection port of the management unit is electrically connected to a load / charger detection clamping circuit.

[0010] Furthermore, one end of the discharge control circuit is electrically connected to the discharge control terminal, and the other end of the discharge control circuit is electrically connected to a first MOSFET. The first MOSFET is electrically connected to a second MOSFET. The second MOSFET is electrically connected to the Pack- terminal of the battery pack. The Pack- terminal is electrically connected to the load / charger detection clamping circuit. The second MOSFET is electrically connected to the anti-reverse current circuit. The first MOSFET is electrically connected to a first resistor. The first resistor is electrically connected to the B- terminal of the battery pack.

[0011] Furthermore, a second resistor is connected in parallel between the first resistor and the first MOSFET, and the second resistor is electrically connected to the current acquisition terminal.

[0012] Furthermore, the anti-backflow circuit includes a first diode and a second diode. The anode of the first diode is electrically connected to the charging control terminal, the cathode of the first diode is electrically connected to the anode of the second diode, and the cathode of the second diode is electrically connected to the second MOSFET. A third resistor is electrically connected to the cathode of the first diode, and the third resistor is electrically connected to the Pack- terminal. A first transistor is electrically connected to the cathode of the second diode, and the first transistor is electrically connected to both the cathode of the first diode and the Pack- terminal.

[0013] The base (b) of the first transistor is electrically connected to the cathode of the first diode, the collector (c) of the first transistor is electrically connected to the Pack- terminal, and the emitter (e) of the first transistor is electrically connected to the cathode of the second diode.

[0014] Furthermore, the charging control terminal is electrically connected to a fourth resistor, the fourth resistor is electrically connected to a second transistor, the second transistor is electrically connected to an anti-backflow circuit, the second transistor is electrically connected to a fifth resistor, and the fifth resistor is electrically connected to the B-terminal of the battery pack.

[0015] The collector (c) of the second transistor is electrically connected to the backflow prevention circuit, the base (b) of the second transistor is electrically connected to the fifth resistor, and the emitter (e) of the second transistor is electrically connected to the fourth resistor.

[0016] Furthermore, the load / charger detection clamping circuit includes a sixth resistor, a Zener diode, and a third diode. One end of the sixth resistor is electrically connected to the load / charger detection port, and the other end of the sixth resistor is electrically connected to the Pack- terminal. The load / charger detection port is connected to the B- terminal after being connected in series with the Zener diode and the third diode.

[0017] Furthermore, the load / charger detection port is electrically connected to the negative terminal of the Zener diode, the positive terminal of the Zener diode is electrically connected to the positive terminal of the third diode, and the negative terminal of the third diode is electrically connected to the B- terminal.

[0018] The load / charger detection port is electrically connected to a capacitor, which is electrically connected to the B- terminal.

[0019] Furthermore, the discharge control circuit includes a seventh resistor, a fourth diode, and a third transistor. One end of the seventh resistor is electrically connected to the discharge control terminal, and the other end of the seventh resistor is electrically connected to the positive terminal of the fourth diode. The negative terminal of the fourth diode is electrically connected to the first MOSFET. The positive and negative terminals of the fourth diode are respectively electrically connected to the base (b) and emitter (e) terminals of the third transistor, and the collector (c) terminal of the third transistor is electrically connected to the base (B-) terminal.

[0020] Furthermore, the gate (G) of the first MOSFET is electrically connected to the discharge control circuit, the source (S) of the first MOSFET is electrically connected to the first resistor, the drain (D) of the first MOSFET is electrically connected to the drain (D) of the second MOSFET, the gate (G) of the second MOSFET is electrically connected to the anti-backflow circuit, and the source (S) of the second MOSFET is electrically connected to the Pack- terminal.

[0021] Furthermore, the protection board body also includes an inter-cell equalization circuit and an internal equalization circuit; the inter-cell equalization circuit equalizes the multiple battery cells, and the internal equalization circuit equalizes the internal cells of each battery cell.

[0022] The internal balancing circuit of the battery cell is electrically connected to each battery cell, and the voltage acquisition terminal of the management unit is electrically connected to the internal balancing circuit of the battery cell.

[0023] The battery cell equalization circuit is electrically connected to each battery cell.

[0024] The beneficial effects of this utility model are:

[0025] The charging MOSFET is protected by an anti-backflow circuit, and the load / charger detection port of the management unit is effectively protected by a load / charger detection clamping circuit. Troubleshooting is simple and maintenance costs are low. This allows the "cubic lithium battery pack" units to be flexibly connected in series to meet the needs of different vehicle models with different voltage levels. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] Example 1:

[0030] like Figure 1 As shown, a series-connectable lithium battery protection board includes a protection board body that protects a battery pack composed of multiple battery cells. The protection board body includes a management unit. The voltage acquisition terminal of the management unit acquires the voltage of the multiple battery cells, the current acquisition terminal of the management unit acquires the current of the battery pack, the discharge control terminal of the management unit is electrically connected to a discharge control circuit, the charging control terminal of the management unit is electrically connected to an anti-reverse current circuit, and the load / charger detection port of the management unit is electrically connected to a load / charger detection clamping circuit.

[0031] One end of the discharge control circuit is electrically connected to the discharge control terminal, and the other end of the discharge control circuit is electrically connected to a first MOSFET Q1. The first MOSFET Q1 is electrically connected to a second MOSFET Q2. The second MOSFET Q2 is electrically connected to the Pack- terminal of the battery pack. The Pack- terminal is electrically connected to the load / charger detection clamping circuit. The second MOSFET Q2 is electrically connected to the anti-reverse current circuit. The first MOSFET Q1 is electrically connected to a first resistor R35. The first resistor R35 is electrically connected to the B- terminal of the battery pack.

[0032] A second resistor R31 is connected in parallel between the first resistor R35 and the first MOSFET Q1, and the second resistor R31 is electrically connected to the current acquisition terminal.

[0033] The backflow prevention circuit includes a first diode D1 and a second diode D2. The anode of the first diode D1 is electrically connected to the charging control terminal, and the cathode of the first diode D1 is electrically connected to the anode of the second diode D2. The cathode of the second diode D2 is electrically connected to the second MOSFET Q2. A third resistor R23 is electrically connected to the cathode of the first diode D1, and the third resistor R23 is electrically connected to the Pack- terminal. A first transistor Q6 is electrically connected to the cathode of the first diode D1 and the Pack- terminal.

[0034] The base (b) of the first transistor Q6 is electrically connected to the cathode of the first diode D1, the collector (c) of the first transistor Q6 is electrically connected to the Pack- terminal, and the emitter (e) of the first transistor Q6 is electrically connected to the cathode of the second diode D2.

[0035] The first transistor Q6 is a PNP transistor.

[0036] The charging control terminal is electrically connected to a fourth resistor R16, which is electrically connected to a second transistor Q4. The second transistor Q4 is electrically connected to an anti-backflow circuit, and the second transistor Q4 is electrically connected to a fifth resistor R22, which is electrically connected to the B- terminal of the battery pack.

[0037] The collector (c) of the second transistor Q4 is electrically connected to the positive terminal of the first diode D1 in the backflow prevention circuit, the base (b) of the second transistor Q4 is electrically connected to the fifth resistor R22, and the emitter (e) of the second transistor Q4 is electrically connected to the fourth resistor R16.

[0038] The second transistor Q4 is a PNP transistor.

[0039] The load / charger detection clamping circuit includes a sixth resistor R26, a Zener diode ZD1, and a third diode D4. One end of the sixth resistor R26 is electrically connected to the load / charger detection port, and the other end of the sixth resistor R26 is electrically connected to the Pack- terminal. The load / charger detection port is connected to the B- terminal after being connected in series with the Zener diode ZD1 and the third diode D4.

[0040] The load / charger detection port is electrically connected to the negative terminal of Zener diode ZD1, the positive terminal of Zener diode ZD1 is electrically connected to the positive terminal of third diode D4, and the negative terminal of third diode D4 is electrically connected to the B- terminal.

[0041] The load / charger detection port is electrically connected to a capacitor C6, which is electrically connected to the B- terminal.

[0042] The discharge control circuit includes a seventh resistor R18, a fourth diode D3, and a third transistor Q7. One end of the seventh resistor R18 is electrically connected to the discharge control terminal, and the other end of the seventh resistor R18 is electrically connected to the positive terminal of the fourth diode D3. The negative terminal of the fourth diode D3 is electrically connected to the first MOSFET Q1. The positive and negative terminals of the fourth diode D3 are respectively electrically connected to the base (b) and emitter (e) terminals of the third transistor Q7. The collector (c) terminal of the third transistor Q7 is electrically connected to the base (B-) terminal.

[0043] The gate (G) of the first MOSFET Q1 is electrically connected to the negative terminal of the fourth diode D3 of the discharge control circuit. The source (S) of the first MOSFET Q1 is electrically connected to the first resistor R35. The drain (D) of the first MOSFET Q1 is electrically connected to the drain (D) of the second MOSFET Q2. The gate (G) of the second MOSFET Q2 is electrically connected to the negative terminal of the second diode D2 of the anti-reverse current circuit. The source (S) of the second MOSFET Q2 is electrically connected to the Pack- terminal.

[0044] Both the first MOSFET Q1 and the second MOSFET Q2 are N-channel enhancement-mode MOSFETs.

[0045] The first transistor Q6, the second transistor Q4, and the third transistor Q7 are all PNP transistors.

[0046] The protection board body also includes an inter-cell equalization circuit and an internal equalization circuit; the inter-cell equalization circuit equalizes the multiple battery cells, and the internal equalization circuit equalizes the internal cells of each battery cell.

[0047] The internal balancing circuit of the battery cell is electrically connected to each battery cell, and the voltage acquisition terminal of the management unit is electrically connected to the internal balancing circuit of the battery cell.

[0048] The battery cell equalization circuit is electrically connected to each battery cell.

[0049] The internal equalization circuit of the battery cell includes equalization resistors and transistors (or MOSFETs), and the equalization circuit between battery cells includes equalization resistors and transistors (or MOSFETs).

[0050] Anti-backflow circuit:

[0051] When the corresponding smallest cell of the battery finishes discharging, its discharge MOSFET turns off, and the battery + vehicle control system stops working. At this time, the positive terminal of the entire system is Pack- of the battery pack, and the negative terminal of the entire system is B- of the battery pack. This causes the charging MOSFET drive section to be subjected to a negative voltage close to the entire voltage. Therefore, the anti-backflow circuit can effectively protect the charging MOSFET drive section.

[0052] Load / charger detection clamping circuit:

[0053] Similarly, at this time, the "load / charger detection" port of the management unit will be subjected to a negative voltage close to the entire voltage. Therefore, the load / charger detection clamping circuit can effectively protect the load / charger detection port of the management unit.

[0054] Battery cell equalization circuit:

[0055] Since there are no other communication or data acquisition lines between the battery cells, only series charging and discharging lines, a threshold voltage-based balancing circuit is needed to ensure the balancing function between battery cells. When a corresponding battery reaches the charging overvoltage threshold voltage V1 in advance, this balancing circuit is activated to divert the charging current of the entire battery pack. For the remaining batteries that have not reached this threshold voltage V1, their "inter-cell balancing" will not be activated, meaning they will not be diverted, thus achieving the balancing effect.

[0056] Internal equalization circuit of the battery cell:

[0057] The "internal balancing" of the battery cell's internal balancing circuit achieves balancing between the internal cells using the same principle as above.

[0058] Through the protection plate body of this embodiment, it is possible to:

[0059] 1. Battery products manufactured using this protection board: flexible installation, free combination, and not picky about battery compartment shape.

[0060] 2. The series-connectable lithium battery protection board allows the "cubic lithium battery pack" units to be flexibly connected in series to meet the needs of different voltage levels in various vehicle models (12V / 24V / 36V / 48V / 60V / 72V), making it a multi-purpose device.

[0061] 3. Facilitates standardized production, improves quality consistency, and reduces costs.

[0062] 4. Benefiting from the series-connectable lithium battery protection board, this battery solution is simpler to troubleshoot, has lower maintenance costs, and is more efficient in troubleshooting and handling compared to integrated lithium battery packs.

[0063] 5. Solve the problem of balancing between battery cells.

[0064] The embodiments described above merely illustrate specific implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A series connectable lithium battery protection board, characterized in that: The protection plate body protects the battery pack composed of a plurality of battery units; the protection plate body includes a management unit, a voltage collection end of the management unit collects voltages of the plurality of battery units, a current collection end of the management unit collects currents of the battery pack, a discharge control end of the management unit is electrically connected with a discharge control circuit, a charging control end of the management unit is electrically connected with an anti-backflow circuit, and a load / charger detection port of the management unit is electrically connected with a load / charger detection clamping circuit.

2. The series lithium battery protection plate according to claim 1, characterized in that: one end of the discharge control circuit is electrically connected with the discharge control end, the other end of the discharge control circuit is electrically connected with a first MOS tube, the first MOS tube is electrically connected with a second MOS tube, the second MOS tube is electrically connected with a Pack- end of the battery pack, the Pack- end is electrically connected with the load / charger detection clamping circuit, the second MOS tube is electrically connected with the anti-backflow circuit, and the first MOS tube is electrically connected with a first resistor, and the first resistor is electrically connected with a B- end of the battery pack.

3. The series lithium battery protection plate according to claim 2, characterized in that: a second resistor is connected in parallel between the first resistor and the first MOS tube, and the second resistor is electrically connected with the current collection end.

4. The series lithium battery protection plate according to claim 2, characterized in that: the anti-backflow circuit includes a first diode and a second diode, a positive electrode of the first diode is electrically connected with the charging control end, a negative electrode of the first diode is electrically connected with a positive electrode of the second diode, a negative electrode of the second diode is electrically connected with the second MOS tube, a negative electrode of the first diode is electrically connected with a third resistor, the third resistor is electrically connected with the Pack- end, a negative electrode of the second diode is electrically connected with a first triode, and the first triode is electrically connected with the negative electrode of the first diode and the Pack- end; a b electrode of the first triode is electrically connected with the negative electrode of the first diode, a c electrode of the first triode is electrically connected with the Pack- end, and an e electrode of the first triode is electrically connected with the negative electrode of the second diode.

5. The series lithium battery protection plate according to claim 2, characterized in that: the charging control end is electrically connected with a fourth resistor, the fourth resistor is electrically connected with a second triode, the second triode is electrically connected with the anti-backflow circuit, the second triode is electrically connected with a fifth resistor, and the fifth resistor is electrically connected with the B- end of the battery pack; a c electrode of the second triode is electrically connected with the anti-backflow circuit, a b electrode of the second triode is electrically connected with the fifth resistor, and an e electrode of the second triode is electrically connected with the fourth resistor.

6. The series lithium battery protection plate according to claim 2, characterized in that: The load / charger detection clamping circuit comprises a sixth resistor, a voltage stabilizing diode and a third diode, one end of the sixth resistor is electrically connected with the load / charger detection port, the other end of the sixth resistor is electrically connected with the Pack- end, and the load / charger detection port is electrically connected with the B- end after being connected with the voltage stabilizing diode and the third diode in series.

7. The series-connectable lithium battery protection board according to claim 6, characterized in that: the load / charger detection port is electrically connected with the negative electrode of the voltage stabilizing diode, the positive electrode of the voltage stabilizing diode is electrically connected with the positive electrode of the third diode, and the negative electrode of the third diode is electrically connected with the B- end; the load / charger detection port is electrically connected with a capacitor, and the capacitor is electrically connected with the B- end.

8. The series-connectable lithium battery protection board according to claim 2, characterized in that: the discharge control circuit comprises a seventh resistor, a fourth diode and a third triode, one end of the seventh resistor is electrically connected with the discharge control end, the other end of the seventh resistor is electrically connected with the positive electrode of the fourth diode, the negative electrode of the fourth diode is electrically connected with the first MOS tube, the positive electrode and the negative electrode of the fourth diode are respectively electrically connected with the b pole and the e pole of the third triode, and the c pole of the third triode is electrically connected with the B- end.

9. The series-connectable lithium battery protection board according to claim 2, characterized in that: the G pole of the first MOS tube is electrically connected with the discharge control circuit, the S pole of the first MOS tube is electrically connected with the first resistor, the D pole of the first MOS tube is electrically connected with the D pole of the second MOS tube, the G pole of the second MOS tube is electrically connected with the anti-backflow circuit, and the S pole of the second MOS tube is electrically connected with the Pack- end.

10. The series-connectable lithium battery protection board according to claim 1, characterized in that: the protection board body further comprises a battery cell inter-battery cell equalization circuit and a battery cell internal equalization circuit; the battery cell inter-battery cell equalization circuit is used for equalizing multiple battery cells, and the battery cell internal equalization circuit is used for equalizing internal battery cells of each battery cell; the battery cell internal equalization circuit is electrically connected with each battery cell, and the voltage acquisition end of the management unit is electrically connected with the battery cell internal equalization circuit; the battery cell inter-battery cell equalization circuit is electrically connected with each battery cell.

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