Laptop Battery Health Checker
Watch your laptop battery live in the browser, and check its real health from a Windows, macOS or Linux battery report. Everything runs on your device. Nothing is uploaded.
The live monitor shows how much charge you have. The health report shows how much battery you have left. Your operating system tracks the original design capacity of the lithium-ion battery and the full charge capacity it holds today. Compare the two and you get your wear level. This tool does that comparison for you. Choose your system, copy the command, run it, and press Analyze.
Battery details
Fields marked “Not available” are not exposed by the browser or your OS report (for example live voltage and milliwatt charge rate need a desktop utility).
Capacity over time (% of design capacity)
Your file is read by this page only. It is never sent to a server.
| Time | Level | State | Event |
|---|
The log records every level change and charger event, plus a line every minute. On a desktop laptop without a battery, browsers report 100% and "charging".
What this battery test can and can't measure
Browsers share only a small amount of battery information with websites: the charge level, whether a charger is connected, and the device's own time estimates. This page adds a running log and a measured drain or charge rate (percent per minute) on top of that.
Battery health is the missing piece. A browser can’t read capacity or wear, because websites don’t get that access. Your operating system does record it, so the health report reads the file your system can produce and turns it into a score you can understand.
How to get a battery report (Windows)
- In the Battery Health Report section above, click Copy command.
- Open Command Prompt (CMD) on your laptop, paste the command, and press Enter.
- Return to this page and click Analyze. The site reads the clipboard — nothing is uploaded.
macOS and Linux
Same idea as Windows: in Battery Health Report, choose macOS, Linux (X11), or Linux (Wayland), then:
- Click Copy command.
- Open Terminal, paste the command, and press Return/Enter. On Linux, install
upowerplusxclip(X11) orwl-clipboard(Wayland) if needed. - Come back and click Analyze. Nothing is uploaded.
Battery health percentage guide
| Battery health | Battery wear | Condition |
|---|---|---|
| 95–100% | 0–5% | Excellent |
| 85–94% | 6–15% | Very good |
| 75–84% | 16–25% | Good, some wear |
| 65–74% | 26–35% | Moderate wear |
| 50–64% | 36–50% | Significant wear |
| 40–49% | 51–60% | Heavily worn |
| Below 40% | Over 60% | Severely worn |
Frequently asked questions
Why does my desktop PC show 100% and charging?
A desktop has no battery, so the browser has nothing to report. It shows a full battery that is plugged in.
Why doesn’t live status work in Firefox or Safari?
Those browsers don’t offer battery information to websites, for privacy reasons. The Battery Health Report works in every browser.
Is my battery report uploaded anywhere?
No. This page reads and analyzes the file in your browser. Nothing leaves your device.
Why does the report say it can’t find capacity values?
Windows writes the report in your system language. The tool reads English labels first, then falls back to the capacity numbers. If it still fails, paste the text of the report.
Should you replace the battery?
Many people start thinking about a replacement once health falls near 70%, or when the laptop dies well before the percentage says it should. Below 50%, most people notice the difference every day. Above 80%, you probably don’t need to do anything.
What is a normal amount of battery wear?
Lithium-ion batteries lose capacity gradually with age and use. Many laptop batteries still hold around 80% after a few hundred full charge cycles. Your result depends on the model, the heat it has faced and how you charge it.
What is the difference between design capacity and full charge capacity?
Design capacity is what the battery held when it was new. Full charge capacity is what it holds today. The gap between them is your battery wear.
How can I make my laptop battery last longer?
Avoid heat, since high temperatures age a lithium-ion cell faster than anything else. Don’t leave the battery at 0% for long periods. If your laptop offers a charge limit in its BIOS or manufacturer app, set it to around 80% for daily desk use.
Does this work on a MacBook?
Yes. Choose macOS, run the command in Terminal, and click Analyze.