Why this site exists
Windows can create a detailed battery report, but the raw HTML file contains technical tables that are not immediately useful to every laptop owner. Our checker extracts the capacity values that matter, calculates the reported health and wear percentages, and explains what the result may mean in plain English.
The site is intentionally focused. It does not promise to diagnose hardware from a single number. It helps you interpret the information your own computer reports so you can decide whether to monitor the battery, adjust how you use it, or speak with the manufacturer or a qualified technician.
Privacy-first processing
The main checker processes a selected battery-report.html file with JavaScript in your browser. The report is not uploaded to Battery Health Lab. You can also enter Design Capacity and Full Charge Capacity manually if you prefer.
How results are calculated
Reported capacity health is calculated as Full Charge Capacity divided by Design Capacity, multiplied by 100. Capacity wear is the difference from 100%. When available, cycle count and capacity history are presented as additional context, not as universal pass-or-fail tests.
Editorial approach
Our guides favor official documentation, clear calculations, cautious language and steps readers can verify themselves. We identify limitations instead of turning estimates into guarantees. Battery Health Lab is not affiliated with Microsoft or any laptop manufacturer.
Corrections and feedback
If you find a parsing problem, unclear explanation or factual error, contact us with the page URL and a description. Please do not email a battery report containing information you do not want to share.