Fast Battery drain on Windows 10 using Hybrid Graphics
Let’s take a look at a typical scenario where you can encounter this issue. You use Windows 10 on a system that supports hybrid graphics. You use an NVIDIA graphics processor unit (GPU) to display to an external monitor. In this scenario, you may continue to see the rapid battery drain for 2 minutes or more. This issue of rapid battery drain when you use Windows 10 on a system that supports hybrid graphics and display to an external monitor, occurs because the dwm.exe (is the window manager in Windows 10/8/7/Vista that enables the use of hardware acceleration to render the graphical user interface of Windows) process continues to reference the discrete GPU (dGPU) even after a video or DirectX application ends and the external monitor is unplugged – Windows 10 continues to maintain power to the dGPU.
Run Power Troubleshooter
If you’re faced with this issue, you can run the Power Troubleshooter and let it check for and automatically detect and fix Power issues.
Hope this helps! P.S: As at the time of writing this post, there is currently no known resolution for this issue on Windows 10. Microsoft is investigating the issue.