Nickel-metal hydride battery management method for acquisition terminal

Abstract

The invention discloses a nickel-metal hydride battery management method for an acquisition terminal, and the method comprises the following steps: periodically disconnecting a charging control loop, and controlling a dummy load loop to be connected to a nickel-metal hydride battery, so as to obtain a real voltage value of the battery under a load; comparing the real voltage value with a plurality of preset voltage threshold ranges; and according to a comparison result, judging the state of the nickel-metal hydride battery as one of battery pull-out, battery failure, battery under-voltage, battery normal or battery full charge, and managing the nickel-metal hydride battery. According to the invention, a relatively simple hardware circuit is adopted, a special electric meter chip or a temperature sensor is not needed, and only a general main control chip, an MOS tube, a resistor and a basic ADC circuit are needed, so that accurate judgment on the working state of the nickel-metal hydride battery is realized, and effective battery charging management is carried out according to a judgment result; and meanwhile, an abnormal battery state is identified and an event is generated to remind maintenance, so that low-cost and high-real-time battery management of the nickel-metal hydride battery of the acquisition terminal is realized.

Description

Technical Field

[0001] This invention relates to the field of battery management technology for data acquisition terminals, and in particular to a method for managing nickel-metal hydride batteries for data acquisition terminals. Background Technology

[0002] Nickel-metal hydride (NiMH) batteries are widely used in data acquisition terminals that require backup power due to their high safety and environmental friendliness. However, since these terminals operate under on-site power supply for most of the time, traditional backup power management solutions leave NiMH batteries in an unpredictable state for extended periods. Both overcharging and prolonged self-discharge can severely shorten battery life. This makes it difficult to detect and manage battery anomalies in a timely manner, potentially leading to insufficient operating time and serious on-site problems when backup power is needed.

[0003] Therefore, timely status monitoring of nickel-metal hydride batteries and the implementation of corresponding charging management schemes are key to avoiding the above-mentioned problems.

[0004] As a widely used rechargeable battery, existing charging management methods for nickel-metal hydride (NiMH) batteries largely rely on dedicated control or sensing chips. These chips primarily manage charging current, temperature, and battery full-charge conditions. Their complex system architecture requires high-precision ADCs and dedicated computing units, resulting in significantly high hardware costs and making them difficult to implement in data acquisition terminals. Furthermore, when NiMH batteries are connected to a data acquisition terminal, their port voltage can be affected by the actual load and internal charging circuitry. Traditional voltage detection methods are prone to misjudging or missing abnormal states such as battery failure or disconnection, hindering effective battery management.

[0005] Known patents related to battery management methods include "An Autonomous Activation, Charge-Discharge Management System and Method for Terminal Nickel-Metal Hydride Batteries" (CN201711457362.3). This invention provides a nickel-metal hydride battery management system and method for devices such as power acquisition terminals. Its core lies in achieving autonomous activation and maintenance of the battery through the integration of an active discharge circuit, a temperature detection circuit, and an intelligent control unit. The system can automatically initiate a "charge-discharge cycle" based on preset conditions (such as periodic intervals or low voltage): first, the battery is actively discharged, then fully charged, thereby breaking the "passivation" state caused by long-term idleness and restoring its activity, thus ensuring that the backup battery can work reliably after installation at the terminal. This invention focuses on the autonomous activation and discharge management of nickel-metal hydride batteries in an idle state under storage conditions, and does not involve real-time status judgment and battery management of nickel-metal hydride batteries in operating acquisition terminals.

[0006] Therefore, there is an urgent need for a nickel-metal hydride battery management solution that can balance low cost, high real-time performance, and accuracy to address the practical pain points of data acquisition terminals and other devices in battery management. Summary of the Invention

[0007] This invention addresses the shortcomings and defects of existing technologies by providing a nickel-metal hydride battery management method for data acquisition terminals. Through the design of ingenious detection and judgment methods and comprehensive management and control logic, and using relatively simple hardware circuitry, it achieves accurate judgment and management of five states of nickel-metal hydride batteries: "unplugged," "failed," "undervoltage," "normal," and "fully charged." This enables low-cost and high-real-time battery management of nickel-metal hydride batteries in data acquisition terminals.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] A method for managing a nickel-metal hydride battery for a data acquisition terminal includes: obtaining the current real voltage value of the nickel-metal hydride battery circuit through a state judgment unit; comparing the obtained real voltage with a plurality of preset voltage threshold ranges; determining the working state of the nickel-metal hydride battery based on the comparison result; and managing the nickel-metal hydride battery based on the working state of the nickel-metal hydride battery.

[0010] The aforementioned nickel-metal hydride battery management method for a data acquisition terminal includes a state detection method and a battery management method.

[0011] The state detection method includes the following steps: repeating the operation at a fixed time period, wherein, in each time period, if the current working state of the nickel-metal hydride battery is that the battery is normal, the dummy load control circuit is opened, the voltage value is obtained through the voltage detection circuit, and the dummy load circuit is disconnected.

[0012] If the current working state of the nickel-metal hydride battery is that the battery is removed, the battery is undervoltage, or the battery is faulty, first disconnect the charging control circuit and open the dummy load control circuit, obtain the voltage value through the voltage detection circuit, disconnect the dummy load circuit and open the charging control circuit.

[0013] If the nickel-metal hydride battery is currently fully charged, the voltage value is obtained directly through the voltage detection circuit.

[0014] The battery management method includes the following steps: if the current working state of the nickel-metal hydride battery is that the battery is removed, then when the voltage value of the nickel-metal hydride battery is lower than a first voltage threshold, the working state is determined to be that the battery is removed; when the voltage value is between the first voltage threshold and a second voltage threshold, the working state is determined to be that the battery is faulty; when the voltage value is between the second voltage threshold and a third voltage threshold, the working state is determined to be that the battery is normal.

[0015] If the current operating state of the nickel-metal hydride battery is: battery normal, battery fully charged, battery undervoltage, or battery failure, then when the voltage value of the nickel-metal hydride battery is lower than the first voltage threshold, the operating state is determined to be battery removed; when the voltage value is between the first voltage threshold and the second voltage threshold, the operating state is determined to be battery undervoltage; when the voltage value is between the second voltage threshold and the third voltage threshold, the operating state is determined to be battery normal; and when the voltage value is higher than or equal to the third voltage threshold, the operating state is determined to be battery fully charged.

[0016] Furthermore, the nickel-metal hydride battery management method for the acquisition terminal can comprehensively judge the battery status by combining the battery running time. When the terminal is powered on by on-site power supply or the battery status is switched from battery removal to other states, timing starts and the time value is recorded as the running time. When the running time is less than 1 hour, battery failure and battery undervoltage events are not recorded. When it is greater than or equal to 1 hour and less than 2 hours, battery failure events are recorded and the battery removal state is also recorded as a battery failure event. When it is greater than or equal to 2 hours, battery undervoltage events are recorded and the battery removal state and battery failure state are both recorded as battery undervoltage events.

[0017] The aforementioned state detection method uses a state judgment unit comprising a voltage detection circuit, a dummy load control circuit, and a charging control circuit. The voltage detection circuit includes resistors R1 and R2, a capacitor C1, and a main control chip N1. The dummy load control circuit includes resistors R3, R4, R5, and R6, and a transistor VT1. The charging control circuit includes a switching power supply chip N2, a bootstrap capacitor C2, an energy storage inductor L1, a capacitor C4, resistors R7 and R8, and a capacitor C3.

[0018] Resistors R1 and R2 in the voltage detection circuit are connected to divide the voltage. Capacitor C1 is connected to the ADC sampling pin of the main control chip N1. The control output pin of the main control chip is connected to the enable pin of the switching power supply chip N2 in the charging control circuit and the base of the transistor VT1 in the dummy load control circuit, connected in series with resistor R3. The base of the transistor VT1 in the dummy load control circuit is also connected in series with a pull-down resistor R4 and ground. The emitter of the transistor VT1 is connected in series with a resistor R5 and ground. The bootstrap capacitor C2 and resistor R7 of the charging control circuit are connected in series with the energy storage inductor L1 and the output pin of the switching power supply chip N2. The output pins are connected as follows: the output terminal VCC1 is connected to a filter capacitor C4, and is connected to the NiMH battery through the positive terminal of the NiMH battery interface J1. The positive terminal of the NiMH battery interface J1 is also connected to the collector resistor R6 of the transistor VT1 in the dummy load control circuit and the resistor R1 in the voltage detection circuit. The negative terminal of the NiMH battery interface J1 is connected to ground. The enable pin of the switching power supply chip N2 is connected to a capacitor C5 for filtering. The enable pin is connected to a series pull-down resistor R8 and ground. The power supply VCC2 of the switching power supply chip N2 is connected to a capacitor C3 for filtering.

[0019] The beneficial technical effects of this invention are as follows: It provides a nickel-metal hydride battery management method for a data acquisition terminal, which adopts a relatively simple hardware circuit. It does not require a dedicated fuel gauge chip or temperature sensor, but only a general-purpose main control chip, MOSFET, resistors and basic ADC circuit. It can accurately determine the working state of the nickel-metal hydride battery and perform effective battery charging management based on the judgment results, effectively preventing overcharging and deep discharge of the battery. At the same time, it can identify abnormal battery states and generate event reminders for maintenance, thereby achieving low-cost and high real-time battery management of the nickel-metal hydride battery of the data acquisition terminal. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a nickel-metal hydride battery management method for a data acquisition terminal provided by the present invention.

[0021] Figure 2 This is a circuit diagram of the voltage detection circuit of the present invention.

[0022] Figure 3 This is a circuit diagram of the dummy load control loop of the present invention.

[0023] Figure 4 This is a circuit diagram of the charging control loop of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and do not limit the scope of the invention.

[0025] like Figure 1 As shown, a nickel-metal hydride battery management method for a data acquisition terminal includes a state detection method and a battery management method.

[0026] The state detection method includes the following steps: repeating the operation at a fixed time period, wherein, in each time period, if the current working state of the nickel-metal hydride battery is that the battery is normal, the dummy load control circuit is opened, the voltage value is obtained through the voltage detection circuit, and the dummy load circuit is disconnected.

[0027] If the current working state of the nickel-metal hydride battery is that the battery is removed, the battery is undervoltage, or the battery is faulty, first disconnect the charging control circuit and open the dummy load control circuit, obtain the voltage value through the voltage detection circuit, disconnect the dummy load circuit and open the charging control circuit.

[0028] If the nickel-metal hydride battery is currently fully charged, the voltage value is obtained directly through the voltage detection circuit.

[0029] The battery management method includes the following steps: if the current working state of the nickel-metal hydride battery is that the battery is removed, then when the voltage value of the nickel-metal hydride battery is lower than a first voltage threshold, the working state is determined to be that the battery is removed; when the voltage value is between the first voltage threshold and a second voltage threshold, the working state is determined to be that the battery is faulty; when the voltage value is between the second voltage threshold and a third voltage threshold, the working state is determined to be that the battery is normal.

[0030] If the current operating state of the nickel-metal hydride battery is: battery normal, battery fully charged, battery undervoltage, or battery failure, then when the voltage value of the nickel-metal hydride battery is lower than the first voltage threshold, the operating state is determined to be battery removed; when the voltage value is between the first voltage threshold and the second voltage threshold, the operating state is determined to be battery undervoltage; when the voltage value is between the second voltage threshold and the third voltage threshold, the operating state is determined to be battery normal; and when the voltage value is higher than or equal to the third voltage threshold, the operating state is determined to be battery fully charged.

[0031] Furthermore, the nickel-metal hydride battery management method for the acquisition terminal can comprehensively judge the battery status by combining the battery running time. When the terminal is powered on by on-site power supply or the battery status is switched from battery removal to other states, timing begins, and the time value is recorded as the running time. When the running time is less than 1 hour, battery failure and battery undervoltage events are not recorded. When it is greater than or equal to 1 hour and less than 2 hours, battery failure events are recorded, and the battery removal state is also recorded as a battery failure event. When it is greater than or equal to 2 hours, battery undervoltage events are recorded, and the battery removal state and battery failure state are both recorded as battery undervoltage events.

[0032] The aforementioned state detection method uses a state judgment unit that includes a voltage detection circuit, a dummy load control circuit, and a charging control circuit; as follows: Figure 2 As shown, the voltage detection circuit includes: resistors R1 and R2, capacitor C1, and main control chip N1; resistors R1 and R2 in the voltage detection circuit are connected to achieve voltage division, capacitor C1 is connected to the ADC sampling pin of the main control chip N1, and the control output pin of the main control chip is connected to the enable pin of the switching power supply chip N2 in the charging control circuit and the base of the transistor VT1 in the dummy load control circuit, respectively, with series resistor R3.

[0033] like Figure 3 As shown, the dummy load control circuit includes: resistors R3, R4, R5, R6, and transistor VT1; the base (B) of transistor VT1 in the dummy load control circuit is connected in series with pull-down resistor R4 and then connected to ground; the emitter (E) of transistor VT1 is connected in series with resistor R5 and then connected to ground; and the collector (C) of transistor VT1 is connected to the output VCC1 of the charging control circuit.

[0034] like Figure 4 As shown, the charging control circuit includes: a switching power supply chip N2, a bootstrap capacitor C2, an energy storage inductor L1, a capacitor C4, resistors R7 and R8, and a capacitor C3. The bootstrap capacitor C2 and resistor R7 of the charging control circuit are connected in series and connected to the energy storage inductor L1 and the output pin of the switching power supply chip N2. The output terminal VCC1 is connected to a filter capacitor C4 and is connected to the nickel-metal hydride battery through the positive terminal of the nickel-metal hydride battery interface J1. The positive terminal of the nickel-metal hydride battery interface J1 is also connected to the collector resistor R6 of the transistor VT1 in the dummy load control circuit and the resistor R1 in the voltage detection circuit. The negative terminal of the nickel-metal hydride battery interface J1 is connected to ground. The enable pin of the switching power supply chip N2 is connected to a capacitor C5 for filtering. The enable pin is connected in series with a pull-down resistor R8 and then to ground. The power supply VCC2 of the switching power supply chip N2 is connected to capacitor C3 for filtering.

[0035] The above embodiments are descriptions of specific implementations of the present invention, and not limitations thereof. Those skilled in the art can make various modifications and changes without departing from the spirit and scope of the present invention to obtain corresponding equivalent technical solutions. Therefore, all equivalent technical solutions should be included in the patent protection scope of the present invention.

Claims

1. A method for managing nickel-metal hydride batteries in a data acquisition terminal, characterized in that, include: The current actual voltage value of the nickel-metal hydride battery circuit is obtained through a state determination unit, which includes a voltage detection circuit, a dummy load control circuit, and a charging control circuit. The voltage detection circuit includes: resistors R1 and R2, capacitor C1, and main control chip N1; The dummy load control circuit includes: resistors R3, R4, R5, R6, and transistor VT1; The charging control circuit includes: switching power supply chip N2, bootstrap capacitor C2, energy storage inductor L1, capacitors C3, C4, and C5, resistors R7 and R8, and nickel-metal hydride battery interface J1. Resistors R1 and R2 in the voltage detection circuit are connected to divide the voltage. Capacitor C1 is connected to the ADC sampling pin of the main control chip N1. The control output pin of the main control chip is connected to the enable pin of the switching power supply chip N2 in the charging control circuit and the base of the transistor VT1 in the dummy load control circuit, connected in series with resistor R3. The base of the transistor VT1 in the dummy load control circuit is also connected in series with a pull-down resistor R4 and ground. The emitter of the transistor VT1 is connected in series with a resistor R5 and ground. The bootstrap capacitor C2 and resistor R7 of the charging control circuit are connected in series with the energy storage inductor L1 and the output pin of the switching power supply chip N2. The output pins are connected as follows: the output terminal VCC1 is connected to a filter capacitor C4, and is connected to the NiMH battery through the positive terminal of the NiMH battery interface J1. The positive terminal of the NiMH battery interface J1 is also connected to the collector resistor R6 of the transistor VT1 in the dummy load control circuit and the resistor R1 in the voltage detection circuit. The negative terminal of the NiMH battery interface J1 is connected to ground. The enable pin of the switching power supply chip N2 is connected to a capacitor C5 for filtering. The enable pin is connected to a series pull-down resistor R8 and ground. The power supply VCC2 of the switching power supply chip N2 is connected to a capacitor C3 for filtering. The obtained actual voltage is compared with multiple preset voltage threshold ranges; Based on the comparison results, the working state of the nickel-metal hydride battery is determined, wherein the working state includes: battery normal, battery removed, battery undervoltage, battery failure, and battery fully charged. The nickel-metal hydride battery is managed based on its operating state.

2. The nickel-metal hydride battery management method for a data acquisition terminal according to claim 1, characterized in that, The step of obtaining the true voltage value of the nickel-metal hydride battery through the state determination loop includes: repeatedly performing the operation at a fixed time period, wherein... Within each time cycle, if the current working state of the nickel-metal hydride battery is normal, the dummy load control circuit is opened, the voltage value is obtained through the voltage detection circuit, and the dummy load circuit is disconnected. If the current working state of the nickel-metal hydride battery is that the battery is removed, the battery is undervoltage, or the battery is faulty, first disconnect the charging control circuit and open the dummy load control circuit, obtain the voltage value through the voltage detection circuit, disconnect the dummy load circuit and open the charging control circuit. If the nickel-metal hydride battery is currently fully charged, the voltage value is obtained directly through the voltage detection circuit.

3. The nickel-metal hydride battery management method for a data acquisition terminal according to claim 1, characterized in that, If the current operating state of the nickel-metal hydride battery is that the battery is removed, then when the voltage value of the nickel-metal hydride battery is lower than the first voltage threshold, the operating state is determined to be that the battery is removed; when the voltage value is between the first voltage threshold and the second voltage threshold, the operating state is determined to be that the battery is faulty; when the voltage value is between the second voltage threshold and the third voltage threshold, the operating state is determined to be that the battery is normal. If the current operating state of the nickel-metal hydride battery is normal, fully charged, under-voltage, or faulty, then when the voltage value of the nickel-metal hydride battery is lower than the first voltage threshold, the operating state is determined to be battery removed; when the voltage value is between the first voltage threshold and the second voltage threshold, the operating state is determined to be under-voltage; when the voltage value is between the second voltage threshold and the third voltage threshold, the operating state is determined to be normal. When the voltage value is higher than or equal to the third voltage threshold, the working state is determined to be that the battery is fully charged.

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