First, check whether each wire is connected in strict accordance with the wiring diagram to ensure that the wiring is correct. Then check whether the latest version of Xiaoxiang APP is installed. Bluetooth should be connected with Xiaoxiang APP. This is Xiaoxiang App download link（http://shouji.baidu.com/software/22854457.html?qq-pf-to=pcqq.group）；
Under normal circumstances, connect the wires according to the wiring diagram, plug in Bluetooth, and install APP to connect Bluetooth and charge and discharge normally. After the undervoltage protection, the bluetooth will be turned off, and the recovery voltage can be restored or the charging can be activated.