mobile APP: For , please directly search E_test in to download and install, then click the Bluetooth app to open the software, click the Bluetooth above the software to enter and select DL24-BLE to be connected, then the remote wireless remote control setting and measurement function of the phone can be realized the discharge status can be checked on the phone at any time, and data cleaning can be seen. Discharge voltage current power curve...... (No need for separate Bluetooth pairing, the software Bluetooth can be directly DL24) Android phone APP: Scan the QR code on the back of the host to download the corresponding APP software after the installation is complete, open the software and click the Bluetooth to directly select DL24-BLE to successfully use it online (no Bluetooth pairing is required, the Bluetooth of the software can directly select DL24) Computer wired APP: After the host is powered on, connect the USB port of the computer with the data cable provided with it, install the CH340 serial port driver, and then scan the QR code on the back of the host to download the corresponding APP software. After the installation is complete, open the software and select the serial port model that has just been installed. Of course, this APP style with the installation mode can also be compatible with the serial port device of the Bluetooth device! Computer Bluetooth wireless connection APP: First add Bluetooth device as DL24-SPP serial port device on the computer, then scan the QR code on the back of the host to download the corresponding APP software and store it, and directly open the software without installation and select the newly added Bluetooth serial port model to successfully use it online First, turn the load switch OFF "off", measure the current no-load vol of the battery, and then the set key to turn the load switch ON "ON", then you can read the internal resistance parameter of the current battery internal resistance calculation formula: (no-load voltage - on-load voltage) Current current = battery internal resistance Built-in intelligent temperature control fan switch design Reduce fan noise and extend fan life! Fast revs, strong winds Support 180W discharge uninterrupted work, suitable for long-term discharge or factory frequency aging test Timing constant current aging function Compatible with four online apps Compatible with four discharge modes Test voltage: 2~200V Working current: 0.2~20A Four on-line modes Colour: Black Material: plastic Package Contents: 1 x USB voltage and current 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.