Novel power bank

Abstract

The utility model provides a novel power bank, which comprises four battery units with the same appearance, and each battery unit comprises one or more rechargeable lithium battery cells which are connected in parallel. The battery units are sequentially connected in series through connecting cables; each battery unit is of a rectangular cylinder structure, and strong magnets are assembled at the same positions of the upper and lower ends of the side walls of the adjacent battery units; micro switches K1 are assembled in the middle parts of the left side walls of the first, second and third battery units; charging and discharging interfaces are assembled on the first battery unit and the fourth battery unit; when the battery units are sequentially attracted together through the strong magnets, the battery units are connected in parallel, and the charging and discharging interface is in an output state. When the battery units are in a mutually separated state, the battery units are connected in series, and the charging and discharging interface is in an input state. When the novel power bank provided by the utility model is used for supplying power, the internal battery units are in a parallel state; the internal battery units are in a series connection state during charging, and can be quickly charged through a high-voltage charger.

Description

Technical Field

[0001] This utility model relates to power banks, and more particularly to power banks that can be fast-charged using high voltage. Background Technology

[0002] With the widespread use of portable and wearable smart electronic devices, replenishing their power anytime, anywhere has become a basic necessity in people's daily lives. Power banks have emerged as an essential item in this context. Power banks utilize high-capacity lithium batteries to store energy and can stably output 5V DC voltage. When needed, they connect to the user's device via a USB cable to charge it. When the power bank itself runs out of power, it needs to be recharged, typically using a 5V DC charger to convert household 220V AC power to 5V DC output.

[0003] One major pain point when charging power banks is the long charging time, often leaving insufficient time to replenish the power bank when needed. In many cases, the charging time is much longer than the actual usage (discharging) time, causing considerable inconvenience. This is because power banks typically use multiple lithium battery cells connected in parallel to increase the power bank's capacity and output power / current. During charging, these parallel cells divert the charger's output current, resulting in a limited charging current for each cell, far below the acceptable charging current limit. On the other hand, increasing the charger's output current would generate a large amount of heat in the internal circuitry. For safety and energy conversion efficiency, thicker internal wiring and stronger components would be needed to handle this heat, leading to a rapid increase in cost. Therefore, considering cost, efficiency, heat dissipation, and safety factors, DC charger manufacturers typically limit the 5V output current to a lower, more universal value (such as 2A). Assuming the charger is charging a power bank with eight 18650 cells connected in parallel, each cell receives a charging current of only 0.25A. Considering that the capacity of lithium battery cells in the industry generally exceeds 2000mAh, the charging current is less than 0.125C, which is far from reaching the standard 0.5C charging and discharging and the 1C-3C fast charging and discharging levels.

[0004] If the battery cells in a power bank are connected in series during charging, it's easy for the charger to increase the charging voltage while maintaining the output current level. Furthermore, each cell will receive a larger charging current, significantly accelerating the charging speed. In fact, many modern chargers already offer multiple output voltage and current specifications through charging standard protocols (such as USB Power Delivery-PD). The charger can "negotiate" with the connected device to determine the most suitable voltage and current combination. For example, a 65W charger supporting the PD protocol offers three output specifications: 20VDC / 3.25A, 15VDC / 3.5A, and 5V / 2A.

[0005] This utility model addresses current market demands by proposing a novel power bank. When in use, the internal battery units are connected in parallel, outputting 5V DC power. When charging, the internal battery units are connected in series, allowing for rapid charging via a 20VDC charger. Utility Model Content

[0006] This utility model proposes a novel power bank, comprising four identical battery units, each containing one or more rechargeable lithium battery cells connected in parallel. The battery units are connected in series via connecting cables. Each battery unit has a rectangular prism structure, with strong magnets mounted at the same positions on the upper and lower ends of the side walls of adjacent battery units. A microswitch K1 is mounted in the middle of the left side wall of the first, second, and third battery units. Charging and discharging interfaces are mounted on the first and fourth battery units. When the battery units are sequentially attracted together by the strong magnets, they are connected in parallel, and the charging and discharging interfaces are in the output state. When the battery units are separated, they are connected in series, and the charging and discharging interfaces are in the input state.

[0007] Preferably, the battery unit further includes a control circuit board, which includes a lithium battery charge and discharge management circuit and a battery unit series and parallel control circuit.

[0008] Preferably, the battery cell series-parallel control circuit includes a power supply positive bus P+, a power supply negative bus P-, a battery cell series control switch Q1, a battery cell parallel control switch Q2, an enable signal Ka for switch Q1, and an enable signal Kb for switch Q2.

[0009] Preferably, the positive terminal of the first battery cell is connected to the positive power supply bus P+, and the negative terminal of the fourth battery cell is connected to the negative power supply bus P-; the negative terminals of the first, second, and third battery cells are each connected to the negative power supply bus P- through a switch Q2, wherein the source of the switch Q2 is connected to the negative terminal of the battery cell, the drain is connected to the negative power supply bus P-, and the gate is connected to the enable signal Kb; the positive terminals of the second, third, and fourth battery cells are each connected to the positive power supply bus P+ through a switch Q2, wherein the drain of the switch Q2 is connected to the positive terminal of the battery cell, the source is connected to the positive power supply bus P+, and the gate is connected to the enable signal Kb; the negative terminal of the preceding battery cell and the positive terminal of the following battery cell are connected through a switch Q1, wherein the source and drain of the switch Q1 are connected to the positive and negative terminals of the preceding and following battery cells, and the gate is connected to the enable signal Ka.

[0010] Preferably, the battery cell series-parallel control circuit further includes an enable signal generation circuit that provides the enable signals Ka and Kb; the circuit includes the micro switch K1, a pull-up resistor, and a logic NOT gate.

[0011] Preferably, the connection relationship of the enable signal generating circuit is as follows: one end of the micro switch K1 is grounded; the other end is connected to the positive power supply bus P+ through the pull-up resistor R, and is also connected to the input terminal of the NOT gate; the input terminal signal of the NOT gate serves as the enable signal Ka, and the output terminal signal of the NOT gate serves as the enable signal Kb.

[0012] Preferably, the connecting cable consists of multiple parallel signal lines, connecting the control circuit boards in two adjacent battery cells; the power positive bus P+, the power negative bus P-, and the signal lines connecting the switch Q1 and the positive terminal of the battery cell are jointly formed by the PCB traces on the control circuit board and the corresponding signal lines in the connecting cable.

[0013] The novel power bank proposed in this utility model has its internal battery units in parallel when it is used for power supply, so as to match the charging voltage required by most smart terminals used daily, such as 5VDC; when charging, the internal battery units are in series, and can be quickly charged by a high-voltage charger.

[0014] Other features and advantages of this utility model will become clearer after reading the detailed description of the embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0015] To clearly illustrate the technical solution and embodiments of this utility model, the accompanying drawings are briefly described below. It should be noted that the drawings are primarily intended to explain the interconnections, structural features, and advantages of the various components of the device, and are not drawn to scale according to the actual dimensions of the device. Obviously, the drawings only relate to a limited set of embodiments and should not be construed as limiting the present utility model. Those skilled in the art can easily obtain new embodiments through formal variations based on these drawings.

[0016] Figure 1 This is a schematic diagram of the structure of one embodiment of the present invention, showing the battery cells in series.

[0017] Figure 2 This is a schematic diagram of the structure of one embodiment of the present invention in which the battery cells are connected in parallel;

[0018] Figure 3 This is a schematic diagram of a series-parallel control circuit in one embodiment of this utility model;

[0019] Figure 4 This is an enable signal circuit diagram in one embodiment of the present invention. Detailed Implementation

[0020] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0021] This utility model proposes a novel power bank, which includes four identical battery units. Each battery unit includes one or more rechargeable lithium battery cells connected in parallel, with a voltage of V0. The battery units are connected in series via cables L1, L2, and L3, as follows: Figure 1 As shown. The battery unit is a rectangular prism structure. Strong magnets N1 are mounted at the same positions on the upper and lower ends of the side walls of adjacent battery units. Specifically, the mounting positions are the right side wall of the first battery unit, the left and right side walls of the second and third battery units, and the left side wall of the fourth battery unit. A microswitch K1 is mounted in the middle of the left side wall of the first, second, and third battery units. Charging and discharging interfaces P1 and P2 are mounted on the first and fourth battery units; preferably, these interfaces are USB interfaces. When the battery unit... Figure 1 When the battery cells are in a separated state, microswitch K1 is in the open state, the battery cells are connected in series, and charging / discharging interfaces P1 and P2 are in the input state. The user can select one or both interfaces to charge the power bank using a charger with an output voltage of 4*V0. When the battery cells are sequentially attracted together by the strong magnet N1, as shown... Figure 2 As shown, when micro switch K1 is closed, the battery cells are connected in parallel, and charging / discharging interfaces P1 and P2 are in output mode. Users can choose one or two interfaces to output power to supply the load.

[0022] The battery unit also includes a control circuit board, which includes a lithium battery charging and discharging management circuit and a battery unit series and parallel control circuit. Figure 3 and Figure 4 The schematic diagram of the series-parallel control circuit for the battery cells is further provided, as follows: Figure 3 As shown, the battery cell series-parallel control circuit includes a power supply positive bus P+, a power supply negative bus P-, a battery cell series control switch Q1, a battery cell parallel control switch Q2, an enable signal Ka for switch Q1, and an enable signal Kb for switch Q2. Specifically, the positive terminal of the first battery cell is connected to the positive power supply bus P+, and the negative terminal of the fourth battery cell is connected to the negative power supply bus P-. The negative terminals of the first, second, and third battery cells are each connected to the negative power supply bus P- via a switch Q2, where the source of switch Q2 is connected to the negative battery cell, the drain is connected to the negative power supply bus P-, and the gate is connected to the enable signal Kb. The positive terminals of the second, third, and fourth battery cells are each connected to the positive power supply bus P+ via a switch Q2, where the drain of switch Q2 is connected to the positive battery cell, the source is connected to the positive power supply bus P+, and the gate is connected to the enable signal Kb. The negative terminal of the preceding battery cell and the positive terminal of the following battery cell are connected via a switch Q1, where the source and drain of switch Q1 are connected to the positive and negative terminals of the preceding and following battery cells, and the gate is connected to the enable signal Ka. The switches are MOSFETs.

[0023] Figure 4 One embodiment of the enable signal is given, in which a pair of contacts (e.g., COM and NO) of microswitch K1 is selected to generate a single input signal. The COM terminal of the microswitch is connected to GND, and the NO terminal of K1 is connected to Vcc (the positive power supply bus P+) through a pull-up resistor R. The NO terminal is also connected to the input of a NOT gate. The input and output of the NOT gate are used as the enable signal Ka. When the microswitch is not pressed, Ka is high and Kb is low, so the switching transistor Q1 is turned on and Q2 is turned off, and the battery cells are in series. When the microswitch is pressed and closed, Ka is low and Kb is high, so the switching transistor Q1 is turned off and Q1 is turned on, and the battery cells are in parallel.

[0024] The cables L1, L2, and L3 consist of multiple parallel signal lines that connect the control circuit boards in two adjacent battery cells. These include the positive power bus P+, the negative power bus P-, and the signal line connecting the source of the switching transistor Q1 to the positive terminal of the battery cell. Specifically, the positive power bus P+, the negative power bus P-, and the signal line connecting the switching transistor Q1 and the positive terminal of the battery cell are formed by the PCB traces on the control circuit board and the corresponding signal lines in the cables L1, L2, and L3.

[0025] The novel power bank proposed in this utility model has its internal battery units in parallel when it is used for power supply, so as to match the charging voltage required by most smart terminals used daily, such as 5VDC; when charging, the internal battery units are in series, and can be quickly charged by a high-voltage charger.

[0026] The description of this utility model is given for illustrative purposes only and is not intended to be exhaustive or to limit the utility model to the disclosed forms. The embodiments were chosen and described to better illustrate the principles and practical applications of the utility model, and to enable those skilled in the art to understand the utility model and design various embodiments with various modifications suitable for a particular purpose. All new embodiments that fall within the basic concept, construction principles, and spirit of this utility model, and are achieved through simple variations, modifications, equivalent substitutions, or improvements, should be included within the scope of protection of this utility model. The scope of this utility model is defined by the appended claims.

Claims

1. A new type of power bank, characterized in that, The power bank comprises four identical battery units, each containing one or more rechargeable lithium battery cells connected in parallel. These battery units are connected in series via a connecting cable. Each battery unit has a rectangular prism structure, with strong magnets mounted at the same positions on the upper and lower ends of the side walls of adjacent battery units. A microswitch K1 is mounted in the middle of the left side wall of the first, second, and third battery units. Charging and discharging interfaces are mounted on the first and fourth battery units. When the battery units are sequentially attracted together by the strong magnets, they are connected in parallel, and the charging and discharging interfaces are in the output state. When the battery units are separated, they are connected in series, and the charging and discharging interfaces are in the input state.

2. The new power bank of claim 1, characterized in that, The battery unit also includes a control circuit board, which includes a lithium battery charging and discharging management circuit and a battery unit series and parallel control circuit.

3. The new power bank of claim 2, characterized in that, The battery cell series-parallel control circuit includes a power supply positive bus P+, a power supply negative bus P-, a battery cell series control switch Q1, a battery cell parallel control switch Q2, an enable signal Ka for switch Q1, and an enable signal Kb for switch Q2.

4. The new power bank of claim 3, characterized in that, The positive terminal of the first battery cell is connected to the positive power supply bus P+, and the negative terminal of the fourth battery cell is connected to the negative power supply bus P-. The negative terminals of the first, second, and third battery cells are each connected to the negative power supply bus P- through a switch Q2, wherein the source of switch Q2 is connected to the negative terminal of the battery cell, the drain is connected to the negative power supply bus P-, and the gate is connected to the enable signal Kb. The positive terminals of the second, third, and fourth battery cells are each connected to the positive power supply bus P+ through a switch Q2, wherein the drain of switch Q2 is connected to the positive terminal of the battery cell, the source is connected to the positive power supply bus P+, and the gate is connected to the enable signal Kb. The negative terminal of the preceding battery cell and the positive terminal of the following battery cell are connected through a switch Q1, wherein the source and drain of switch Q1 are connected to the positive and negative terminals of the preceding and following battery cells, and the gate is connected to the enable signal Ka.

5. The new power bank of claim 3, characterized in that, The battery cell series-parallel control circuit further includes an enable signal generation circuit that provides the enable signals Ka and Kb; the circuit includes the micro switch K1, a pull-up resistor, and a logic NOT gate.

6. The novel power bank according to claim 5, characterized in that, The connection relationship of the enable signal generating circuit is as follows: one end of the micro switch K1 is grounded; the other end is connected to the positive power supply bus P+ through the pull-up resistor R, and is also connected to the input terminal of the NOT gate; the input terminal signal of the NOT gate serves as the enable signal Ka, and the output terminal signal of the NOT gate serves as the enable signal Kb.

7. The novel power bank according to any one of claims 3-6, characterized in that, The connecting cable consists of multiple parallel signal lines, connecting the control circuit boards in two adjacent battery cells; the power positive bus P+, the power negative bus P-, and the signal lines connecting the switch Q1 and the positive terminal of the battery cell are jointly formed by the PCB traces on the control circuit board and the corresponding signal lines in the connecting cable.

Images