If the camera has been charged for hours but still cannot be turned on after long pressing the power button, you can try to reboot it. The reboot steps are different for different models of cameras. Please find the reboot steps for your camera below.
For most battery cameras, you will find the reboot hole near the power button which is located at the bottom of the camera covered by a silicone cover. Please open the silicone cover, press the reboot hole with the pin included in the box or a pointed tool like a paperclip, and gently apply pressure on the pin/pointed tool. After releasing the pin/pointed tool, the camera will restart automatically in which you will see the indicator light( blue or white, depending on the camera's model) on, and hear a startup sound.
For some battery cameras with a removable shell (e.g. camera as shown in the following figure), you need to open the back shell of the camera, and then open the rubber plug on the side of the camera. Next press the reboot hole with the pin included in the box or a pointed tool like a paperclip, and gently apply pressure on the pin/pointed tool. After releasing the pin/pointed tool, the camera will restart automatically in which you will see the blue light on and hear a startup sound.
For PTZ battery cameras, the reboot hole is also near the power button which is located at the top of the ball part. Please open the silicone cover and press the reboot hole with the pin included in the box or a pointed tool like a paperclip, and gently apply pressure on the pin/pointed tool. After releasing the pin/pointed tool, the camera will restart automatically in which you will see the blue light on and hear a startup sound.
If the issue still persists, please submit feedback from the app for further technical assistance.