Use PowerCfg in Windows 7 to Evaluate Power Efficiency

It’s quite annoying when you have work to do on your laptop and the battery is dead or low on power. Even if you’ve selected the Power Saver plan, there could be other factors causing the battery to drain too quickly. Today we take a look at using the PowerCfg command to generate a power efficiency report.

Generate Report

To generate the report you’ll need to use the Elevated Command Prompt as Administrator. Click on Start and type CMD into the search box, then right-click the command prompt icon and select Run as Administrator.

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Next type in the following command to generate the report on energy efficiency:

powercfg -energy

It takes a full 60 seconds for the report to generate. and you’ll see the following message in the command screen when it’s finished. Notice it shows the number of errors and warnings contained in the report.

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The Power Efficiency Diagnostics Report is saved in HTML format in your local user drive. Now you can read through the analysis and try to determine what is causing so much power to drain. In this example in the errors section it’s showing Sleep Mode is disabled and a USB device is not turning off when not in use. 

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Sections of Report

So what does this report even mean? Well, it’s broken down into 4 sections and we’ll take a look at each one. The first section of the report contains the basic system information like the system name, BIOS, manufacturer…etc.

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The second section contains the Errors with a red background. These are problems that have a huge effect on power consumption and battery life. Problems classified as Errors can affect battery life by 15% or more. 

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The next section are Warnings that have a yellow background. The problems indicate a moderate effect of power consumption and battery life. They are not as critical to fix as Errors, but if you can fix them, it will help improve efficiency.

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The last part of the report contains informational data with a white background, and don’t indicate any energy problems. This lists the system components that were inspected for the report.

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Conclusion

There is a lot of detailed information is the report and it may not be the most exciting thing to read, but make sure to look over it closely. In the example above we just needed to go into Power Options and configured Sleep Mode and kept the USB Flash drive unplugged when not using it. Each computer will vary and a solution might be tweaking Power Options or installing an updated hardware driver. If you are unsure what the report is telling you, go to our forum and ask one of the many knowledgeable geeks in there, they’ll be happy to help!

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Brian Burgess worked in IT for 10 years before pursuing his passion for writing. He's been a tech blogger and journalist for the past seven years, and can be found on his about me page or Google+