Recently we received some complaints about the terrible battery consumption after they replaced the battery for F3. It is not the hardware issue but wrong installation, when you put the back cover back to the watch. Here I made a video battery installation and what needs to pay attention to.
Here is the video. As you see, the notch must be toward to the right corner, that will make sure the two spring/battery pin not in the same board. That will cause the watch to short-circuit, and the battery will drain very fast.