5v step-up and step-down multi-section nickel-hydrogen battery self-identifying section charging circuit
By designing a 5V step-up/step-down multi-cell nickel-metal hydride battery self-identification charging circuit, the problems of multiple customers sharing circuits and inconsistent software in existing technologies are solved. This achieves automatic identification and constant current charging, improving production efficiency and the uniformity of hardware and software.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN ANHAOXIN TECH CO LTD
- Filing Date
- 2025-07-04
- Publication Date
- 2026-07-07
AI Technical Summary
Existing nickel-metal hydride battery charging solutions cannot achieve shared circuitry and software among multiple customers, resulting in numerous and inconsistent solutions, which increases the difficulty of research and development and production.
Design a 5V step-up/step-down multi-cell nickel-metal hydride battery self-identification charging circuit. The circuit uses resistors and transistors to form input voltage, battery voltage, and charging current detection lines, and combines MCU control to achieve automatic identification and constant current charging.
It achieves automatic identification and full charging of multiple nickel-metal hydride battery packs, with unified hardware and software, shortening the development cycle and reducing the problem of multiple production models.
Smart Images
Figure CN224473085U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of 3C multi-cell nickel-metal hydride charging technology, and in particular to a 5V buck-boost multi-cell nickel-metal hydride battery self-identification charging circuit. Background Technology
[0002] Nickel-metal hydride batteries are still widely used in people's daily lives in the current market. Currently, due to diverse customer needs, these products employ dedicated charging circuits and customized hardware and software for each customer. This makes it impossible for multiple customers to share the same circuits and software, resulting in numerous, inconsistent solutions that hinder research and development and production. Utility Model Content
[0003] The purpose of this invention is to provide a 5V step-up / step-down multi-cell nickel-metal hydride battery self-identifying cell number charging circuit to solve the above-mentioned technical problems.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] A charging circuit for a 5V step-up / step-down multi-cell nickel-metal hydride battery with self-identification of cell count is provided. Resistor R1 is connected to USB+, and resistor R2 is connected to the other end of resistor R1 and the other end of resistor R2 is connected to USB-, forming an input voltage detection circuit.
[0006] The source (S) of PMOS transistor Q1 is connected to USB+, the drain (D) of PMOS transistor Q1 is connected to L and the negative terminal of diode D1, the gate (G) of PMOS transistor Q1 is controlled by the MCU, the positive terminal of diode D1 is connected to USB-, the other end of L is connected to the drain of NMOS transistor Q2 and the positive terminal of diode D2, the negative terminal of diode D2 is connected to capacitor C2 and the positive terminal of the battery pack, and the source (S) of NMOS transistor Q2 is connected to the other end of capacitor C2 and USB-, forming a buck-boost circuit;
[0007] Resistor R3 is connected to the positive terminal of the battery pack. The other end of resistor R3 is connected to one end of resistor R4. The other end of resistor R4 is connected to USB-, forming a battery voltage detection circuit.
[0008] One end of resistor R5 is connected to the negative terminal of the battery pack, and the other end of resistor R5 is connected to USB-, forming a charging current detection circuit.
[0009] Preferably, resistor R5 is selected as an mR-level resistor.
[0010] Compared with the prior art, this utility model has the following advantages: It fundamentally solves the problems of automatic identification and full charging of multiple nickel-metal hydride battery packs, the convenience of unified software and hardware, and the drawbacks of long development cycles and many production models caused by different customer needs. Attached Figure Description
[0011] Figure 1 This is the circuit schematic diagram of this utility model. Detailed Implementation
[0012] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0013] like Figure 1 As shown, a 5V step-up / step-down multi-cell nickel-metal hydride battery self-identification charging circuit is provided. Resistor R1 is connected to USB+, resistor R2 is connected to the other end of resistor R1, and the other end of resistor R2 is connected to USB-, forming an input voltage detection circuit.
[0014] The source (S) of PMOS transistor Q1 is connected to USB+, the drain (D) of PMOS transistor Q1 is connected to L and the negative terminal of diode D1, the gate (G) of PMOS transistor Q1 is controlled by the MCU, the positive terminal of diode D1 is connected to USB-, the other end of L is connected to the drain of NMOS transistor Q2 and the positive terminal of diode D2, the negative terminal of diode D2 is connected to capacitor C2 and the positive terminal of the battery pack, and the source (S) of NMOS transistor Q2 is connected to the other end of capacitor C2 and USB-, forming a buck-boost circuit;
[0015] Resistor R3 is connected to the positive terminal of the battery pack. The other end of resistor R3 is connected to one end of resistor R4. The other end of resistor R4 is connected to USB-, forming a battery voltage detection circuit.
[0016] One end of resistor R5 is connected to the negative terminal of the battery pack, and the other end of resistor R5 is connected to the USB- terminal, forming a charging current detection circuit. Resistor R5 is selected in the mR range.
[0017] Functional principles of each module:
[0018] VUSB: Detects the USB input voltage. The voltage is divided by resistors R1 and R2 in the circuit and then fed into the MCU ADC for detection via VUSB.
[0019] B+: Detects battery voltage. The voltage is divided by R3 / R4 in the circuit and then enters the MCU ADC for detection via B+.
[0020] IChg: Charging current detection; in the circuit, it enters the MCU ADC for detection via R5 through ICHG.
[0021] The step-down charging section consists of the part shown in the blue box. Q1 is a MOS step-down switch, and D1 is the L freewheeling diode. At this time, L is the step-down inductor.
[0022] The boost charging section consists of the part shown in the red box. Q2 is a MOS boost switch, and D2 is a Schottky diode that charges C2 unidirectionally to achieve the boost purpose. At this time, L is the boost inductor, and C2 is the energy storage and filtering capacitor.
[0023] Detect VUSB and B+ voltages & Ichg to achieve boost charging & constant current process:
[0024] When VUSB > B+, buck charging starts to work;
[0025] When VUSB <= B+, boost charging starts to work;
[0026] Realization of buck operation: The NMOS outputs a low level to keep in an inoperative state, and the PMOS adopts a PWM operating mode, continuously detecting Ichg and achieving constant current charging. (The constant current principle will be explained later)
[0027] Realization of boost operation: The PMOS outputs a low level and remains in a conducting state all the time. The NMOS adopts a PWM operating mode, continuously detecting Ichg and achieving constant current charging.
[0028] Realization of constant current: Detect IChg. When IChg < ICC (required charging current), increase the PWM duty cycle; when ICHG >= ICC, decrease the PWM duty cycle.
[0029] Detect the number of battery cells and clarify the conditions for full charge - DV to facilitate the subsequent full charge judgment:
[0030] This method uses the full charge characteristics of nickel - hydrogen batteries - DV. When the battery reaches full charge, it will not boost anymore but will decrease instead, and this characteristic is used to judge the number of battery cells.
[0031] During the detection of B+, statistically count the B+ voltage every 1 second. If the B+ voltage does not rise or drops within 10 seconds (0DV method), then determine the current B+ voltage as the highest voltage (VMAX). The number of battery cells in the battery pack CELLS = VMAX / 1.5V;
[0032] Full charge judgment: When CELLS is determined during the detection of B+, determine the full charge condition - DV = -CELL * 10MV.
[0033] Judgment method of -DV: Continuously record the B+ voltage during charging and record the highest voltage VMAX. -DV = VMAX - B+. If the -DV condition reaches the full charge condition - DV = -CELL * 10MV, it can be determined that the battery pack is fully charged and the charging process ends.
[0034] The above is a preferred embodiment of the present utility model. For those of ordinary skill in the art, according to the teachings of the present utility model, without departing from the principles and spirit of the present utility model, any changes, modifications, substitutions, and variations made to the embodiments still fall within the protection scope of the present utility model.
Claims
1. A charging circuit for a 5V step-up / step-down multi-cell nickel-metal hydride battery with self-identification of cell count, characterized in that, Resistor R1 is connected to USB+, and resistor R2 is connected to the other end of resistor R1. The other end of resistor R2 is connected to USB-, forming an input voltage detection circuit. The source (S) of PMOS transistor Q1 is connected to USB+, the drain (D) of PMOS transistor Q1 is connected to L and the negative terminal of diode D1, the gate (G) of PMOS transistor Q1 is controlled by the MCU, the positive terminal of diode D1 is connected to USB-, the other end of L is connected to the drain of NMOS transistor Q2 and the positive terminal of diode D2, the negative terminal of diode D2 is connected to capacitor C2 and the positive terminal of the battery pack, and the source (S) of NMOS transistor Q2 is connected to the other end of capacitor C2 and USB-, forming a buck-boost circuit; Resistor R3 is connected to the positive terminal of the battery pack. The other end of resistor R3 is connected to one end of resistor R4. The other end of resistor R4 is connected to USB-, forming a battery voltage detection circuit. One end of resistor R5 is connected to the negative terminal of the battery pack, and the other end of resistor R5 is connected to USB-, forming a charging current detection circuit.
2. A charging circuit for a 5V step-up / step-down multi-cell nickel-metal hydride battery with self-identification of cell count, characterized in that, Its features are, Resistor R5 should be an mR-class resistor.