After Ebike eliminates battery discharge, common causes of sudden power outage and insufficient power include poor line contact, controller failure, motor failure and abnormal brake power-off switch. They can be checked and solved in a simple to complex order. First of all, poor circuit contact is the most common cause. If the battery interface, controller interface, and motor wiring are loose or oxidized, it will lead to unstable power supply, power outage or insufficient power. When troubleshooting, you can turn off the power, check whether each interface is plugged in tightly, wipe the oxide layer of the interface with a dry cloth, and test after reconnecting. Secondly, the controller is faulty. The controller is the "brain". If there is a short circuit or the components are damaged, it will not be able to transmit power normally, which will be manifested as a sudden drop in power or a sudden power outage. You can observe whether there are burnt marks or odor on the controller. If so, the controller needs to be replaced. Thirdly, motor failure, water intrusion into the motor, damage to the coil or failure of the Hall element will result in insufficient power or even power outage. You can check whether the motor wiring is intact and whether there are traces of water ingress. If the motor cannot rotate normally, it needs to be sent to a professional repair shop for inspection and repair. Finally, the brake power-off switch is abnormal. If the brake power-off switch is stuck or has poor contact, it will accidentally trigger the power-off function, causing a sudden power outage during riding. You can check the switch at the brake handle and press it gently to see if it rebounds normally. If it is stuck, apply a small amount of lubricant. If it is damaged, replace the switch.