I have written an app that displays navigation infos on the watch. It uses opengl for drawing. While the app is running and the watch face is not visible, the watchmaker process is still consuming CPU time. In ambient mode, I disable the GLSurfaceView by calling onPause. But watchmaker is still using CPU time, even if it is not visible. This causes a high battery drain. If I use one of the other watch faces, the problem does not occur. Also if I remove the GLSurfaceView from my app, the problem does also not occur. Are you stopping your render thread if an app is running? Could also be a wear bug. I'm using a sony smartwatch 3 with the latest android 5.1.1.