This is a multifunctional instrument based on wireless data transmission technology, which can display various physical parameters such as voltage, current, power, capacity, energy, temperature, and operating time in real-time. Moreover, the instrument adopts a mobilephone app and a 2.4-inch color LCD screen (optional) as the display, which displays data more comprehensively, clearly, and is easy to observe. There is a reserved communication interface for secondary development. Features: Wireless data transmission eliminates interference from complex wiring between the display and the detection module. Mobilephone app display for convenient data viewing and settings adjustment, enhancing oper ability. The 2.4-inch LCD screen automatically light up and turn off, facilitating visibility while reducing power consumptions. Integrated design with a standard 50MV purecopper shunt for current detection offers low power consumption, minimal temperature rise, high accurancy, compact size, and increased stability. Simultaneous display of voltage, current, power, temperature, capacity, remaining capacity percentage, and runtime, with a complete history of data curves. Equipped with recharging overvoltage, discharging undervoltage, recharging overcurrent, discharging overcurrent, and over temperature alarm functions. Power-off memory function records AH and WH counts before power loss, along with all parameters. Capable of monitoring the voltage of both the main and auxiliary batteries. The app supports viewing of voltage, current, temperature, historical data curves, as well as data saving and export functions. Features voltage and current online adjustment, with app device password protections. Equipped with a TTL serial communication port, convenient for secondary development. Switchable display languages between English and Chinese to meet diverse customer needs. Specifications: Model: KL300A, KL500A (optional) Type: with display screen, without display screen (optional) Main battery input voltage range: 8-120V Startup battery input voltage range: 0-120V Current measurement range: KL300A: 0.03-300A KL500A: 0.05-500A Capacity measurement range: 0.0-6500.0AH Energy measurement range: 0.0-6500.0KWH Power measurement range: 0.0-999KW Temperature measurement range: -20 to 150 Operational powerconsumption: TypicalValue