Where does powercfg save the battery report?

In the folder the command window is open in, and it prints the full path when it finishes. In a normal Terminal or PowerShell window that is your user folder (C:\Users\your name\battery-report.html); in a window opened as administrator it is C:\Windows\System32. Add /output followed by a path to choose the place yourself.

What do design capacity and full charge capacity mean?

Design capacity is how much energy the battery was built to hold when new, in milliwatt-hours (mWh). Full charge capacity is how much it holds now when charged to 100%. Full charge divided by design is the battery health percentage this page shows.

Why does my battery report show no cycle count?

The count comes from the battery itself, through the laptop’s firmware, and some laptops do not pass it to Windows. The report then shows a dash. The capacity figures are still the better guide to wear.

My report is not in English. Does it still work?

Yes. Windows writes the report in the computer’s display language, and this page reads its structure, dates and numbers rather than its headings. The power states in the recent usage table are shown in the report’s own words beside a plain plugged in, on battery or asleep.

Can a website check my battery without a report?

No. Browsers do not let web pages read battery capacity or cycle counts, only at most the current charge level. That is why the report is made by Windows first and then opened here.

Is it safe to open my battery report here?

The report contains your computer’s name, its model and when it was used. This page reads the file in your browser and sends nothing anywhere, so those details stay on your device.

Stays on your computer How this works

Battery report viewer: check your laptop battery health

Open the battery report Windows makes with powercfg and see in plain words how worn the battery is, with its capacity over time and recent battery use - read in your browser, nothing uploaded

How to make your battery report (Windows, about a minute)

A web page cannot read the battery itself, so Windows writes the details to a file for you first.

Right-click the Start button and choose Terminal (on Windows 10, Windows PowerShell). Command Prompt works too.
Type this command and press Enter: powercfg /batteryreport
Windows answers with the place it saved the file, for example C:\Users\yourname\battery-report.html. It goes in the folder the window was open in: your user folder normally, or C:\Windows\System32 if you opened it as administrator.
Drop that battery-report.html file below, or click the box and pick it. Several reports at once work too, for example from two laptops, or from the same laptop months apart.

Prefer the raw data? powercfg /batteryreport /xml saves battery-report.xml, which opens here too . On a Mac, System Settings, Battery shows the battery’s health, and System Information (under Power) shows its cycle count. iPhones show Battery Health in Settings, Battery; Android phones show what they offer under Settings, Battery.

Drag & drop battery-report.html here, or browse

Tap to choose a battery report

battery-report.html or .xml from powercfg · one or many · nothing is uploaded

About this battery report viewer

Opens: The battery report Windows 10 and 11 save with powercfg /batteryreport (battery-report.html, in any display language) and its XML version (/xml).
Shows: How much charge the battery still holds as a percentage of when new, design and full charge capacity, cycle count, chemistry and maker, a chart of capacity over time, battery life estimates and recent battery use. Each battery is shown when a laptop has two.
Saves: A summary as text, the capacity history and a side-by-side summary as CSV, and each chart as PNG.
Works on: Any modern browser, so a report can be checked on another computer or a phone too.
Price: Free, with no sign-up.
Privacy: The report names the computer and records when it was used; it is read on this page and never uploaded.
Cannot: Read the battery directly (no web page can), repair or recalibrate it, or check Mac and phone batteries, which show their own figures in their settings.

Every laptop battery slowly loses capacity as it is charged and used, and as it ages. Windows keeps track of it: the powercfg /batteryreport command writes a report with the capacity the battery was designed for, the capacity it reaches on a full charge today, the number of charge cycles, and weeks of history. The report is a page of tables, though, and it never says in words whether the battery is fine or worn out.

This page reads that report and puts the answer first: the share of its original charge the battery still holds, what that level of wear usually means, how capacity has changed over the months, and how long a charge is estimated to last now compared with when it was new. It reads the report by its structure rather than its wording, so a report from a German, French, Japanese or any other Windows works the same as an English one. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.

What is normal wear?

Lithium batteries wear with every cycle and with time, faster when kept at full charge, run flat often or kept hot. As a rough guide, a battery that holds 90% or more of its design capacity is in very good shape, 80 to 90% is ordinary wear after a year or two of daily use, and below 80% you will usually notice shorter battery life. Many makers rate laptop batteries for somewhere around 300 to 1,000 cycles before they drop to about 80%, but the figure varies by model, so your maker’s documentation is the place to check.

The capacities come from the battery’s own fuel gauge, which estimates them. A new battery can read a little over 100%, and figures can jump up or down by a few percent between reports. A trend over several months says more than one reading.

What to do about a worn battery

Turn on your laptop’s battery care or charge limit if it has one (often in the maker’s app, for example a setting that stops charging at 80%), which slows further wear.
Keep the laptop out of heat, and avoid leaving it at 100% on the charger all day when you do not need the full charge.
If capacity has fallen well below 80% while the laptop is still under warranty, the maker may replace the battery.
A swollen battery, one that gets very hot, or a laptop that suddenly shuts down at a high charge level needs attention from a repair shop or the maker straight away; stop using it on battery meanwhile.

How to check your battery health on Windows

Open Terminal, Windows PowerShell or Command Prompt from the Start button’s right-click menu.
Run powercfg /batteryreport; Windows prints where it saved battery-report.html.
Drop that file on this page.
Read the verdict at the top, then the capacity chart and estimates below it. Save the summary or the charts if you want to keep them or send them to a repair shop.

Questions

Where does powercfg save the battery report?: In the folder the command window is open in, and it prints the full path when it finishes. In a normal Terminal or PowerShell window that is your user folder (C:\Users\your name\battery-report.html); in a window opened as administrator it is C:\Windows\System32. Add /output followed by a path to choose the place yourself.
What do design capacity and full charge capacity mean?: Design capacity is how much energy the battery was built to hold when new, in milliwatt-hours (mWh). Full charge capacity is how much it holds now when charged to 100%. Full charge divided by design is the battery health percentage this page shows.
Why does my battery report show no cycle count?: The count comes from the battery itself, through the laptop’s firmware, and some laptops do not pass it to Windows. The report then shows a dash. The capacity figures are still the better guide to wear.
My report is not in English. Does it still work?: Yes. Windows writes the report in the computer’s display language, and this page reads its structure, dates and numbers rather than its headings. The power states in the recent usage table are shown in the report’s own words beside a plain plugged in, on battery or asleep.
Can a website check my battery without a report?: No. Browsers do not let web pages read battery capacity or cycle counts, only at most the current charge level. That is why the report is made by Windows first and then opened here.
Is it safe to open my battery report here?: The report contains your computer’s name, its model and when it was used. This page reads the file in your browser and sends nothing anywhere, so those details stay on your device.

For a PC that crashes with a blue screen rather than a tired battery, open the crash files Windows saves in the Crash Dump Viewer.