If you have owned your Windows 11 laptop for a few years, you might notice it doesn’t hold a charge as long as it used to. Laptop batteries physically degrade over time, losing their maximum capacity. While the standard Windows battery icon simply says “100%,” that percentage only represents the current degraded capacity, not the original factory capacity.
To find out exactly how much your battery has degraded (and whether it is time to buy a replacement), you must ask Windows to generate a highly detailed, hidden HTML report directly from the hardware power sensors.
How to Safely Extract the Windows 11 Battery Health Report
You must use the `powercfg` utility in the Command Prompt to generate and extract the hidden report.
- Click the Start button, type cmd, and press Enter to launch the Command Prompt.
- You must tell Windows to poll the hardware sensors and export the data into a readable HTML file. Carefully type the following exact command:
powercfg /batteryreport /output "C:\battery_report.html" - Press Enter. (If you get an access denied error, try saving it to your user folder instead, e.g.,
powercfg /batteryreport /output "C:\Users\YourName\battery_report.html"). - The terminal will confirm that the “Battery life report saved to file path.” You can now close the Command Prompt.
- Open File Explorer, navigate to your C: drive, and double-click the newly generated
battery_report.htmlfile. It will open in your default web browser.
Scroll down to the section titled Installed batteries. You need to look at two specific numbers: Design Capacity and Full Charge Capacity.
The “Design Capacity” is how much power the battery held on the day it was manufactured (e.g., 60,000 mWh). The “Full Charge Capacity” is the absolute maximum amount of power it can physically hold today (e.g., 42,000 mWh). If the Full Charge Capacity is significantly lower than the Design Capacity, your battery has severely degraded, and you need to replace the physical hardware.