Powercfg command - Laptop Battery Report and much more

http://www.sevenforums.com/tutorials/4569-power-efficiency-diagnostics-report.html
excerpt below:
The Power Efficiency Diagnostics will analyze your system for common energy efficiency and battery life problems, and report any errors, warnings, and informational details found.
This tutorial will show you how to run a power efficiency diagnostics report of your computer in Windows 7 and Windows 8.
warning:
You should run this report when your computer is idle and with no open programs or documents for the best results.

Here's How:
1. Open an elevated command prompt in Windows 7 or Windows 8.
(right click on cmd, run as admin)
2. In the elevated command prompt, copy and paste the command below, and press Enter. (see screenshot below)
NOTE: This will take 60 seconds to run by default. When done it will give you a quick report of any problems found and place a detailed Energy_Report.html file on your desktop.
powercfg -energy -output %USERPROFILE%\Desktop\Energy_Report.html

You could also change the command to be able to use your own location for where you want the Energy_Report.html file to be placed (outputted) at.

powercfg -energy -output "C:\Energy_Report.html"


other links:
http://www.hanselman.com/blog/PowerCfgTheHiddenEnergyAndBatteryToolForWindowsYoureNotUsing.aspx

http://www.sevenforums.com/general-discussion/67440-powercfg-flashes-sec-then-gone-help.html