Design of intelligent management system for nickel-cadmium rechargeable aaa alkaline batterybased on microcontroller

　　As a type of alkaline battery, nickel-cadmium rechargeable aaa alkaline batteryhave special requirements for use, management and maintenance. If they are not properly managed, used improperly, and maintained in a timely manner, it can easily lead to battery aging, failure or even scrapping. In view of the different types of nickel-cadmium rechargeable aaa alkaline batterythat are widely used in special applications, factories and mines and are stored centrally, an intelligent battery management system is designed using single-chip microcomputer control technology to carry out automatic status detection, charge and discharge management, performance maintenance and other intelligent functions for nickel-cadmium rechargeable batteries. management.

　　Through the automatic management of nickel-cadmium rechargeable batteries, the blindness and randomness in the use and management of nickel-cadmium rechargeable aaa alkaline batteryare effectively eliminated, the efficiency of nickel-cadmium rechargeable aaa alkaline batteryis improved, and the service life of nickel-cadmium rechargeable aaa alkaline batteryis extended.

　　The special requirements for the use, management and maintenance of nickel-cadmium rechargeable aaa alkaline batteryare mainly reflected in: 1) They are required to be stored under suitable temperature conditions and a non-acidic environment; 2) The aaa alkaline batteryshould be maintained regularly during long-term storage, and initialization should be carried out before new aaa alkaline batteryare used. Capacity recovery; 3) Single aaa alkaline batterywith large performance differences cannot be used or charged in the same group, and scrapped aaa alkaline battery(or faulty batteries) cannot be mixed with serviceable batteries; 4) aaa alkaline batteryshould be discharged to the end voltage before charging. To eliminate the "memory effect" that may occur in nickel-cadmium rechargeable batteries, and to avoid overcharging and over-discharging the battery; 5) Use pulse charging as much as possible to improve the charging efficiency of the battery and extend the service life of the battery.

　　The designed and produced intelligent management system for nickel-cadmium rechargeable aaa alkaline batterycan meet the special requirements for use, management and maintenance of nickel-cadmium rechargeable aaa alkaline batterythrough centralized storage and automatic charge and discharge management of batteries.

　　1System functions and functions

　　The nickel-cadmium rechargeable battery intelligent management system is used to intelligently manage nickel-cadmium rechargeable aaa alkaline batterythat are used in large quantities and stored centrally. It mainly completes functions such as battery storage, automatic battery detection and automatic charge and discharge management, battery maintenance and initial capacity recovery, battery fault detection and indication alarm, battery polarity reverse indication alarm, battery no-load indication and temperature control. The system functional block diagram is shown in Figure 1.

　　2 System composition and principle

　　The system consists of a control module, a battery detection module, a charge and discharge module, a battery switching module, a temperature control module, a battery storage module and a power supply module. Among them, the control module is composed of a single-chip microcomputer and peripheral circuits, and is used to realize charge and discharge control, battery switching control, temperature control, battery detection and indication control; the charge and discharge module is composed of a charge and discharge circuit, and is used to realize the charging and discharging of rechargeable batteries; The switching module consists of a relay and its control drive circuit, and is used to realize automatic or manual switching between battery cells. The temperature control module consists of a temperature sensor, an axial fan and a control circuit, and is used to monitor and control the temperature of the battery storage environment. After the system starts working and passes the self-test, it first detects the battery status, removes faulty aaa alkaline batteryand corrects reverse-connected batteries, and then enters the battery management stage to charge and discharge the battery cells in sequence.

　　3Hardware design

　　3.1 Control module design

　　Select AT89S52 microcontroller as the control unit. The p0 port of the microcontroller is used for digital display and keyboard scanning. Among them, p0.0~p0.3 are used to output the 4-digit binary number corresponding to the battery code, which is converted into a 7-segment code by 74LS248 and sent to the digital tube for display. p0.3 and p0.4 are controlled by timer T0, and cyclically output 00, 01, 10, and 114 2-digit binary numbers. After being decoded by the decoder 74LS139, they are used as scanning signals to simultaneously control the digital tube and matrix keyboard. scanning. p0.5 and p0.6 are used to monitor the status of each key of the 2×4 matrix keyboard. Port p1 is used to continuously output 8-bit binary numbers. After cascade decoding by the two-stage decoder 74LS154, it can output up to 256 control signals to realize automatic switching control of 256 battery cells in sequence. The p2 port is used to detect the status of the rechargeable battery (no load, fault, fully charged, fully discharged) and control the charging and discharging of the battery. The p3 port is mainly used for battery status (empty, full, fault, reverse connection) monitoring, indication and alarm. Battery switching module design#e#

　　3.2 Battery switching module design

　　The battery switching module consists of a driving circuit and a switching circuit array composed of relays. Among them, each switching circuit unit corresponds to a battery cell. The drive circuit is mainly composed of the inverter 74LS04 and the transistor S9013. It is controlled by the control signal output from the p1 port to control the open and closed state of the relay. The dual electric shock relay 4137 that can convert two signals at the same time is used to realize simultaneous switching of the charge and discharge circuit and the battery status detection circuit. The interrupt control function of the external interrupt INT1 is used, and the status of the two switching buttons is detected and judged through p3.6 of the microcontroller. At the same time, the "move up" and "move down" buttons are used to realize manual switching between battery cells. The switching unit circuit between battery cells is shown in Figure 3.

　　3.3 Charge and discharge module design

　　The charging and discharging module consists of a charging circuit, a discharging circuit and a charging and discharging control circuit. The charging or discharging control signal output by the microcontroller controls the charging or discharging circuit to charge or discharge the battery respectively. The battery charging and discharging circuit is shown in Figure 4.

　　3.4 Voltage detection module design

　　The voltage detection module consists of a three-terminal voltage stabilizing circuit, a voltage dividing circuit and a comparison circuit. The three-terminal voltage stabilizing circuit is composed of LM317 and its peripheral circuits. Its output voltage is divided by the voltage divider circuit and used as the reference voltage. It is sent to one end of the comparator composed of LM339. The voltage collected from the positive electrode of the battery is sent to the comparison At the other end of the comparator circuit, the current battery power and placement status can be judged from the level status of the output of each comparator. These status signals are used as detection signals and then sent back to the microcontroller, which controls the operation of the charge and discharge circuit and indicates the battery status.

　　4Software design

　　The system software consists of monitoring program, automatic management program, system self-test subroutine, battery detection subroutine, manual switching interrupt subroutine, button and digital tube scanning subroutine, etc. After the system starts working, it first calls the system self-test subroutine. If the system or a certain module is not working properly, the system will sound an alarm and the digital tube will flash and display the fault module code. If the system and each module are working normally, the system calls the battery detection subroutine to check and judge the fault, reverse connection and no-load condition of each battery cell in the system, and simultaneously displays the position code of the detected battery cell, and The faulty battery and reverse-connected battery will be detected and the alarm will be indicated. After all aaa alkaline batteryare tested, the system automatically enters the automatic battery management program and performs automatic cycle charge and discharge management of the batteries. In the automatic management program, the system first discharges the battery, and then charges it after discharging to the termination voltage. At the same time, during the charging process, the software delay is used to cause the nickel-cadmium rechargeable battery to discharge briefly between charging, thereby effectively improving the battery charging efficiency through pulse charging and minimizing the possible polarization of the nickel-cadmium rechargeable battery. Phenomenon.

　　5 other functions

　　5.1 Temperature control

　　Nickel-cadmium rechargeable aaa alkaline batteryhave certain requirements for the storage environment temperature, so a temperature control module is designed in the system to monitor and control the ambient temperature of the battery. The temperature control module consists of a temperature sensor [7], signal processing circuit, A/D conversion circuit, relay and control circuit, and axial fan. When the ambient temperature reaches the set upper limit temperature, the microcontroller controls the relay to close and then controls the axis. The flow fan rotates to ventilate and cool the battery storage environment. After the ambient temperature reaches the appropriate temperature, the microcontroller control relay is disconnected and the axial fan stops rotating. This ensures that the ambient temperature of the battery storage environment is always within a suitable range.

　　5.2 Battery maintenance

　　For newly activated nickel-cadmium rechargeable aaa alkaline batteryor nickel-cadmium rechargeable aaa alkaline batterythat have polarized phenomena, charge and discharge maintenance is generally required, mainly to restore the initial capacity and activate performance of the battery. The maintenance method is to deeply discharge and charge the battery three times in a row. Once the system is started and has passed the battery test, it will always be in the battery automatic management state. If a battery needs to be maintained, you can control the system to switch to the battery that needs maintenance by operating the "Move Up" and "Move Down" buttons. , and then press the "Maintenance" button, the system will interrupt automatic management and enter the battery maintenance program. After the maintenance is completed, the system continues to be automatically managed.

　　6 Conclusion

　　First of all, the system provides a storage environment with independent space and constant temperature for the nickel-cadmium rechargeable aaa alkaline batterythat are centrally placed and managed uniformly, eliminating the possible adverse effects of acidity, high temperature and other adverse factors on the nickel-cadmium rechargeable batteries. Secondly, the pulse charging and discharging method is used in the battery charging and discharging management and maintenance process, which not only improves the battery charging and discharging efficiency, but also maintains or restores the performance of nickel-cadmium rechargeable batteries. Third, the system adopts the method of first discharging and then charging for charge and discharge management, which can eliminate the "memory effect" that may occur in nickel-cadmium rechargeable aaa alkaline batteryand improve the efficiency of rechargeable batteries. Fourth, the battery charge termination and discharge termination voltages are monitored and controlled in real time to avoid battery overcharge and overdischarge, and extend the service life of nickel-cadmium rechargeable batteries. Fifth, the operation mode of first detection, then management and single charge and discharge is adopted to prevent single nickel-cadmium rechargeable aaa alkaline batterywith large performance differences from being used in the same group or charging in the same group.

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