USB Voltmeter Ammeter Detector Voltage Current Tester Charger LCD Monitor Features: 1. It can detect the charging capacity of the battery of the tablet and mobile phone, judge how much the battery performance has decreased and whether it needs to be replaced. 2. It can detect the discharge capacity of the charging bank and calculate the conversion rate of the charging bank. 3. It can detect the charging current of your digital device. 4. Working current of 5V router and any other 5V USB device (such as USB light) It comes with a USB input line and a microrousb port, which can be input with other lines. One end is connected to the power supply/mobile power supply. Note that the USB interface is used by default, that is, 5v; The other end is connected to the load, which can be a mobile phone. 5. It is simple and easy to use without professional wiring. As long as you plug in the USB port and discharge and charge, you can monitor the working current and voltage of the device and count the battery capacity. The screen surface of the new machine is pasted with protective film, which can be removed if it is not necessary. Specifications: Input voltage: 3V-15V Voltage resolution: 0.01V Test current: 0.05A-3.50A Current resolution: 0.01A Capacity range: 0-19999mAH Accuracy: ± 1% Line loss: about 0.1 Ω Test: Battery voltage, current and discharge capacity (10 sets of data in total) Measuring voltage and current: Plug in 5V charger on the USB male and mobile phone on the female to directly read the voltage and current parameters Measure the quality of MicroUSB cable: For devices such as mobile phones in the female seat, first plug in the 5V charger with the local male connector, remember the voltage, and then plug the MicroUSB cable from the 5V charger into the local MicroUSB hole to remember the voltage. The smaller the voltage difference, the better the quality of the MicroUSB cable Measure battery capacity: Use TP4056 and other linear charging circuits to fully charge the completely dead battery through this capacity meter, and the capacity reading is the battery capacity. This method can also measure the mobile phone charging capacity, and even calculate the mobile phone charging efficiency Measure the output capacity and efficiency of mobile power supply: First connect the mobile power supply to the mobile phone, turn on the mobile power supply, press and hold the key until the capacity data returns to zero, and plug in the mobile phone for several times until the mobile power supply is powered off automatically. The next time the machine is turned on, the display capacity is the mAH of mobile power output. Note that this mAH is far smaller than the nominal mAH, output mAH * output voltage 5V/battery mAH * battery voltage 3.7V=mobile power efficiency Data reset: Press and hold the key until (which group of data) becomes the next group, and then release the key to automatically jump to the next group of data from zero. Data viewing: Double-click the key quickly (within 0.5S) to enter the data viewing mode, the backlight LED will flash, and then the next group of data will be displayed again. Double-click to exit the data viewing mode, and the backlight LED will be on for a long time. Alarm for high or low voltage: The LCD arrow and backlight LED will flash, and the alarm will prompt. Press the button and the LED will stay on for 30s. Power-on status: Connect the power through MicroUSB or USB male with cable, and the LCD screen will display all the contents for 1s (check whether the LCD screen is intact), and then display the last data (capacity, and group of data), current voltage, current and voltage are high or low. Data calibration function setting: one electronic load meter and one constant current source. The constant current source is adjusted to 8.5V and below 10V (9V is recommended), and the electronic load is set to CC mode (constant current mode). The four currents of 3A, 2A, 1A and 0.3A are calibrated respectively. Take 3A as an example: 3A calibration: the electronic load is set to constant current mode 3A, and the current of the LCD screen of the electricity meter will be automatically and slowly calibrated (about 10S). You can see that the current of the LCD screen will change. After calibration, turn off the automatic protection of the electronic load data. Package includes: 1 * USB tester Note: 1. Due to manual measurement, please allow an error of 1-3 mm. Please confirm that you don't mind before ordering. 2. Please allow 1-3 g weight error. Please make sure you don't mind before ordering. 3. Due to the difference of light and display in the picture, the picture may not reflect the actual color of the object. Please make sure you don't mind before ordering, thank you!