Read a saved Windows battery report to compare design capacity with full-charge capacity, estimate the reported capacity shortfall, and show cycle count when Windows supplies it.
Private by design: your report stays in this browser.The selected HTML file is parsed locally. This tool does not upload it, send extracted battery figures to a server, or run commands on your computer.
How the calculation works
Windows reports Design Capacity and Full Charge Capacity for batteries that expose those values. This tool calculates Full Charge Capacity divided by Design Capacity, multiplied by 100. A lower ratio means the report currently shows less available capacity than the original design figure.
Some reports omit cycle count or other fields. Missing values are shown as unavailable rather than estimated. If Full Charge Capacity is above Design Capacity, reporting or calibration variation may explain it; the tool does not calculate negative wear.
What this result cannot tell you
Capacity is not the same as remaining runtime. Background workloads, brightness, sleep behavior, temperature, battery calibration and the laptop’s power profile can change how long it runs. Compare runtime under similar conditions and check the device maker’s own diagnostic guidance before ordering a replacement.
Battery safety comes first
A low capacity figure alone does not mean a battery is dangerous. Swelling, leaking, physical damage, unusual heat, or a chemical odor are separate warning signs. Stop using a visibly swollen or damaged battery, do not charge or press on it, and arrange qualified service. Never puncture or open a battery pack.
Frequently asked questions
How do I create a battery report in Windows?
Open Windows Terminal or Command Prompt and run powercfg /batteryreport. Open the HTML file path printed by Windows, then select that saved report in this tool. You run the command yourself; this tool does not run commands on your PC.
Is my battery report uploaded?
No. The HTML report is read and parsed in your browser. Tech World Window does not receive the file or the battery values extracted from it.
How is capacity loss estimated?
The capacity ratio is Full Charge Capacity divided by Design Capacity, multiplied by 100. A result below 100% means the reported full-charge capacity is below the design figure. It does not predict exact runtime, cell condition, or the date a battery will fail.
What if Windows does not report a cycle count?
Some manufacturers do not expose every battery field in the report. The analyzer shows cycle count only when it is present and does not fill missing data with guesses.
Does low reported capacity mean the battery is unsafe?
Not by itself. Capacity loss can mean shorter runtime. Swelling, unusual heat, odor, leakage, or physical damage are separate safety warnings. Stop using a swollen or damaged battery and arrange qualified service; do not puncture or open a battery pack.
