Product firmware upgrade instructions: 1. The startup information has changed. If you need to turn off information monitoring, please long the "M" key to enter the background and turn off the information prompt! 2. Battery percentage ( full voltage and 0% low battery voltage) and OVP (overvoltage alarm), (low voltage alarm) need to be set separately, which can be set to the same value or different values 3. This product is a bidirectional current, with a+symbol for charging and a - symbol for discharging, changed to the direction of the (charging position ← symbol, discharging → symbol) 4. When encountering WiFi connection failure, long the"M" key to enter the background and select the WiFi reset option 5. The system sound can be turned off or on, long the "M" key to enter the background settings 6. Language selection, long the "M" key to enter the background settings APP upgrade instructions: 1. Increase battery percentage display (numerical and graphical display) 2. Charging as current, power not change, discharging: The symbol - be displayed in front of the current power value, for example, charging 12.0V 1.00A 12.00W, discharging: 12.0V -1.00A -12.00W is displayed 3. Graph curve: Real time data can be opened, and the data change in real time All data is uploaded to the cloud once an hour and displayed, calculated on average every hour Specifications: WIFI online version 30A Color: Black Material: plastic Package Contents: 1 * Lithium Battery Capacity Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.