As the description states, it is best to run while the system is idle, much like the WinSat "Windows Experience Index" process. Running powercfg -energy, you end up with results like this: Enabling tracing for 60 seconds... Observing system behavior... Analyzing trace data... Analysis complete. Energy efficiency problems were found. 21 Errors 17 Warnings 10 Informational Using the default options, a file called energy-report.html will be created in the current directory from which powercfg.exe execute and gives you a snapshot of your system energy consumption over a 60 second period. My Laptop's Report is attached to give you an idea of what to expect from the report. The Biggest thing in the report for me is that it shows you exactly the charge of your battery and its design capacity. If you have any questions please feel free to get back to me on this.