# Check Laptop Battery Health on Windows with the powercfg Battery Report

> Generate a battery report with powercfg /batteryreport, compare design and full charge capacity to measure wear, and decide whether the battery needs replacing.

Source: https://www.epifive.com/blog/laptop-battery-health-report-windows-powercfg · Published 2026-10-28 · EpiFive

## Key takeaways

- Run powercfg /batteryreport to create an HTML battery report in the current folder, or use /output to choose the file name and location.
- Battery wear is design capacity compared with full charge capacity; dividing the second by the first gives a health percentage.
- Design capacity is the estimated energy capacity of a new battery, and full charge capacity is what the battery holds when fully charged now.
- A single odd reading can be misleading, so check the report after a full charge and compare it with how long the laptop really lasts.
- Powercfg can also write XML with /xml and limit the period analysed with /duration days.

Open Windows Terminal or Command Prompt and run `powercfg /batteryreport`. Windows creates an HTML file in the current folder. Open it in a browser and compare Design capacity (what a new battery holds) with Full charge capacity (what yours holds now) under Installed batteries; dividing full charge by design gives your battery health as a percentage.

## Who this is for

This is for anyone whose Windows laptop seems to run out of charge faster than it used to and who wants a measurement before paying for a replacement battery or a new laptop. You will end with a battery report, a calculated health percentage, an understanding of what the other report sections show, and a decision framework. It applies to Windows 10 and Windows 11 laptops and tablets that have a battery.

## What powercfg is

`powercfg.exe` is a command-line tool built into Windows. Microsoft documents it as a way to control power plans, the sleep states and device power states, and to analyse the system for energy-efficiency and battery-life problems. One of its options, `/batteryreport`, generates a report of battery usage characteristics over the lifetime of the system.

## Prerequisites

- A laptop or tablet with a battery that reports to Windows. Desktops have no battery. Microsoft's BatteryReport documentation says values return null when the battery is not present or when the value is not reported by the battery controller.
- Windows Terminal, Command Prompt or PowerShell.
- A web browser to open the HTML file.
- Ideally, the laptop charged to 100 percent before you read the numbers, with no heavy tasks running. A reading taken right after a long discharge can mislead, which is explained in the troubleshooting section.

## Generate the battery report

### Quick method

1. Right-click Start and select Terminal (or Windows Terminal). Command Prompt and PowerShell also work.
2. Run:

```powershell
powercfg /batteryreport
```

3. The command prints the path of the saved file. Microsoft says it generates an HTML report file in the current path, so a terminal opened in your user folder saves it there.

If the command reports an error about writing the file, choose a folder you own with `/output`, shown next.

### Choose where the file is saved

The `/output` option sets the path and file name:

```powershell
New-Item -ItemType Directory -Path C:\Temp -Force | Out-Null
powercfg /batteryreport /output "C:\Temp\batteryreport.html"
Invoke-Item "C:\Temp\batteryreport.html"
```

`Invoke-Item` opens the file in your default browser. Create the folder first if it does not exist, as the first line does.

### Limit the period or save XML

Microsoft documents two more options for this command:

```powershell
powercfg /batteryreport /duration 14
powercfg /batteryreport /output "C:\Temp\batteryreport.xml" /xml
```

`/duration` sets the number of days to analyse. `/xml` formats the report as XML, which is easier to process with scripts. Use the HTML for reading.

## Read the report

The report opens with general information about the computer, then moves to the battery. The key section describes the installed battery.

### Design capacity and full charge capacity

Microsoft's Windows API documentation defines the two values you need:

| Value | Meaning |
|---|---|
| Design capacity | The estimated energy capacity of a new battery of this type |
| Full charge capacity | The fully charged energy capacity of the battery now |

Both are shown in milliwatt-hours (mWh) in the report. A new battery has a full charge capacity close to its design capacity. Over time, full charge capacity falls as the battery ages.

### Calculate battery health

Use this simple formula:

```text
Battery health (%) = Full charge capacity / Design capacity x 100
```

For example, with a design capacity of 50,000 mWh and a full charge capacity of 40,000 mWh, health is 80 percent. Those numbers are an illustration, not a measurement from a real machine.

You can calculate it in PowerShell too:

```powershell
$design = 50000
$full   = 40000
[math]::Round($full / $design * 100, 1)
```

Replace the two values with the numbers from your report, without commas.

### Other sections

The report also contains tables for how the laptop has used its battery. Typical sections include recent usage, battery usage over the last days, usage history, battery capacity history and battery life estimates. Look at the capacity history if you want to see wear over weeks or months rather than one reading, and the usage sections to see how long the battery actually lasted on recent days.

Some labels vary by Windows version and manufacturer. If you do not see a particular section, rely on the capacity numbers and your own experience of runtime.

## Decide whether to replace the battery

There is no universal Microsoft threshold. Use the report together with these checks.

| Evidence | What it suggests |
|---|---|
| Full charge capacity close to design capacity, but runtime is short | Software or settings are using more power. Review Power mode, brightness and background apps first. |
| Full charge capacity well below design capacity | The battery has aged. Replacement will restore runtime. |
| Full charge capacity falls sharply from one report to the next | Check the battery condition promptly and consider service. |
| The laptop shuts down suddenly with charge showing | A worn battery or a calibration problem is possible. Get it checked. |
| The battery is swollen, the case is bulging or the trackpad lifts | Stop using and charging it, and take it to a service centre. |

Check your laptop's warranty and the manufacturer's support page. Many makers define what counts as a battery defect, and the rules differ by brand and country. Use the report as supporting evidence when you speak to support.

### Try software fixes first

Microsoft's guidance for saving battery life includes choosing a more efficient power mode, shortening the screen-off and sleep timers, using battery saver, and closing apps you are not using. In Windows 11 the power mode is under Settings, System, Power and battery, and Microsoft says you can choose a different option for Plugged in and On battery. The Energy recommendations panel on the same page can apply several power-saving settings at once. See /blog/laptop-fan-noise-loud-fix-cleaning for how power mode also affects heat and fan noise.

### Replacement options

Replacing the battery is often cheaper than replacing the laptop. Use the manufacturer's service centre or an authorised repairer, and a battery that matches the model. Some thin laptops have the battery glued in, which makes DIY replacement difficult and risky; if the maker gives a service guide for your model, use it. Check the price from the maker's official page at the time you decide, as prices change.

## Verify and track over time

1. Save the first report and note the date, design capacity, full charge capacity and your health percentage.
2. Run the command again every few months and compare the new full charge capacity with the old one.
3. A steady slow decline is normal. A sudden drop deserves attention.

Keep the HTML files in a folder named by date, for example `batteryreport-2026-10-28.html`, so you can compare them later.

## Troubleshooting

| Problem | What to try |
|---|---|
| Command not recognised | Open Terminal or Command Prompt and type powercfg /? to confirm the tool is present. It is part of Windows. |
| No report file appears | Check the printed path, or use /output with a full path such as C:\Temp\batteryreport.html. |
| Access denied when saving | Save to a folder you own with /output. |
| Design capacity equals full charge capacity | Some battery controllers report poorly. Compare with real-world runtime. |
| Full charge capacity looks far too low | A transient reading can occur. Charge fully, leave the laptop for a while and run the report again. Update the BIOS and chipset drivers from the maker. |
| The report has no battery section | The device may be a desktop or a virtual machine, or the battery controller may not report values. |
| Capacity shows normal but battery drains fast | Look for background apps in Settings, System, Power and battery, and check energy settings and screen brightness. |

## Checklist

- Charge the laptop fully and close heavy apps.
- Run `powercfg /batteryreport /output "C:\Temp\batteryreport.html"` and open the file.
- Note design capacity and full charge capacity, and calculate the percentage.
- Compare with your real-world runtime and with older reports.
- Try power mode, brightness and background-app changes first.
- Contact the maker or an authorised service centre if capacity is low or the battery is swollen.
- Repeat every few months and keep the reports.

## References

- Microsoft Learn, Powercfg command-line options: https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/powercfg-command-line-options
- Microsoft Learn, BatteryReport class (Windows.Devices.Power): https://learn.microsoft.com/en-us/uwp/api/windows.devices.power.batteryreport
- Microsoft Support, Change the power mode for your Windows PC: https://support.microsoft.com/en-us/windows/change-the-power-mode-for-your-windows-pc-c2aff038-22c9-f46d-5ca0-78696fdf2de8
- Microsoft Support, Battery saving tips for Windows: https://support.microsoft.com/en-us/windows/experience/power-battery/battery-saving-tips-for-windows

## Frequently asked questions

### How do I check laptop battery health in Windows 11?

Open Windows Terminal or Command Prompt and run powercfg /batteryreport. Windows saves an HTML report in the current folder. Open it in a browser and compare Design capacity with Full charge capacity under Installed batteries.

### Where is the battery report saved?

Microsoft says powercfg /batteryreport generates an HTML file in the current path. Use the /output option, for example powercfg /batteryreport /output "C:\Temp\batteryreport.html", to choose where it is saved.

### What is a bad battery health percentage for a laptop?

There is no single Microsoft threshold. Divide full charge capacity by design capacity to get a percentage. The lower it falls, and the shorter your real-world runtime, the stronger the case for replacement. Check your laptop maker's guidance and warranty terms before deciding.

### Why does the battery report show no battery information?

Microsoft's API documentation says battery values are not returned when the battery is not present or the battery controller does not report them. Desktops and some virtual machines have no battery to report on.