Posted by: kurtsh | August 20, 2012

HOWTO: Determine if your Windows laptop battery is dying in just 60 seconds

A fact of life is that laptop batteries don’t last forever. But it’s a fact that we largely forget about, and we blame Windows for being a “power pig” & only until the battery completely fails do we consider that it’s a hardware issue.  The truth is that a lot of folks find their laptop’s battery doesn’t last very long and the reason is… it’s OLD!  And it’s dying! 

So how does one figure out – without too much effort, whether their battery is failing and if they want better battery life, they need to get a battery replacement?  It turns out that in Windows 7 & Windows 8, we have some great tools that make it very easy to determine how well your machine is doing power-wise in just 60 seconds.


  1. Open a CMD shell with Administrative privileges in Windows 7 or 8.
  2. Run POWERCFG /ENERGY and a 60 second analysis will be run on your machine.
  3. If any issues arise, the analysis will tell you how many issues the OS found on the screen once it’s finished.  A report should be written to your \windows\system32 directory called “energy-report.html


The resulting HTML file will tell you a lot.  For example, one of the things it will tell you is what applications are the biggest power hogs on your system.  On my system for example, besides the usual suspects, like Internet Explorer, I found some surprising CPU hogs on there like Soluto & Windows Live Writer.  Something to know when you’re on the road and want to conserve battery.

The thing you’re looking for in this case is in the 3rd section, near the end entitled, “Battery:Battery Information”.  There are two numbers you need to look at in this section:

  • Design Capacity
  • Last Full Charge

These two numbers should be relatively close to each other obviously.  On my PC for example, I have a Design Capacity of 52170 and a Last Full Charge of 48770, meaning that the maximum charge I can hold on my battery is apparently about 93.5%.  Not bad.

If you have largely divergent numbers, you probably have yourself a bad battery and it’s time to replace it.


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