Free Laptop Battery Checker — Check Your Battery Status Online
The TechTester laptop battery checker reads your device’s battery level, charging status, and estimated time remaining directly in your browser using the W3C Battery Status API no software download required, no installation, no account. Open this page on your laptop, Chromebook, or Android tablet and your battery information appears instantly. This free online battery checker works on any device running Google Chrome, Microsoft Edge, or Opera. It is the fastest way to check your battery status right now without digging through system settings or installing third-party software. Scroll down for detailed battery health guides for Windows, Mac, Android, and to understand what your battery readings actually mean.
Laptop Battery Tester & Info
Live diagnostics, health estimate, specs & calculators
Live Readings
- Charge level—
- Charging—
- Time to full—
- Time remaining—
- Estimated rate—
Battery Health Calculator
Find these values in your laptop's battery report (Windows: powercfg /batteryreport · macOS: System Information → Power · Linux: upower -i $(upower -e | grep BAT)).
Battery Specs Database
Wh ↔ mAh Converter
Runtime Estimator
Export Latest Results
Download your most recent Live Test reading and Health calculation as a CSV spreadsheet or a printable PDF report. Run the tests in their tabs first — empty fields appear as “N/A”.
Live Test snapshot
- No data captured yet
Health snapshot
- No calculation captured yet
What this battery checker shows you
The TechTester laptop battery checker uses the W3C Battery Status API built into modern browsers. This is the same data source your operating system uses to display the battery icon in your taskbar. Here is exactly what the tool reads from your device:
Battery level
Your current battery percentage from 0% to 100% updated in real time as the battery charges or discharges.
Charging status
Whether your laptop is currently Charging, Discharging (on battery), or Full (plugged in and at 100%).
Time remaining
Estimated minutes until fully charged (if charging) or until battery depleted (if discharging).
What requires OS tools
We believe in being completely honest about what a browser based tool can and cannot do. The following deeper battery health metrics require operating system level access which browsers do not have by design. For these metrics, use the free OS tools in Section E below:
Not available via browser
Battery wear level percentage
Design capacity vs full charge capacity
Charge cycle count
Battery temperature
Voltage and current draw
Battery manufacture date
Predicted battery end of life
Available via OS tools
Windows: powercfg /batteryreport command
Mac: System Information → Power section
Mac: coconutBattery (free app)
Android: Samsung Members app diagnostics
Android: *#*#4636#*#* battery info code
Chrome OS: chrome://system battery section
All OS tools are free and built in
TechTester competitive advantage: batterychecker.org only shows a download prompt. agecalcai.com shows basic readings but no OS guide. timbrica.com is good but text heavy and hard to navigate. TechTester gives the browser tool AND the full OS guide on one clean page making it the most complete free battery resource online.
How to check your laptop battery online – 3 steps
Open the battery checker in a supported browser
This tool requires Google Chrome, Microsoft Edge, Opera, or any Chromium based browser. Firefox removed Battery Status API support in version 52 for privacy reasons. Safari on Mac and iPhone has never implemented it. If you are on Firefox or Safari, scroll to Section E for your OS specific battery health guide instead.
Read your battery information
Your battery level, charging status, and time remaining appear automatically the moment the page loads no button to press, no permission required. The battery level shows as a percentage and updates in real time. If your laptop is charging, the tool shows how many minutes until full. If on battery, it shows estimated time remaining before the battery depletes.
Understand what the readings mean
A battery level above 20% is normal operating range. Below 20% your laptop will typically activate low battery warnings. A charging status of ‘Full’ means your laptop is plugged in and at 100% this is healthy. If the time remaining shows as ‘Unknown’ or a very unusual number, this is a browser or OS reporting limitation and does not indicate a fault with your battery.
How to check deep battery health on every device
The browser tool above shows your live battery status. For full battery health data wear level, cycle count, and design capacity use the free built in tools below. Choose your operating system:
Windows 10 and Windows 11 Battery Report
Windows includes a free built in battery diagnostics tool that generates a detailed HTML report showing your battery’s full health history. Here is how to run it:
- Press the Windows key, type cmd, right click Command Prompt, and select Run as administrator
- Type the following command exactly and press Enter: powercfg /batteryreport
- Windows will confirm the report has been saved note the file path shown (usually C:\Users\YourName\battery-report.html)
- Open File Explorer, navigate to that path, and double click battery report.html to open it in your browser
- Look for these key sections: Design Capacity (original battery capacity in mWh), Full Charge Capacity (current maximum in mWh), and Cycle Count
Calculate your battery health percentage: divide Full Charge Capacity by Design Capacity and multiply by 100. For example, if Design Capacity is 45,000 mWh and Full Charge Capacity is 36,000 mWh, your battery health is 80% meaning it has lost 20% of its original capacity.
80–100% health — Good
Battery is in excellent condition. No action needed. Normal for laptops under 2 years old.
50–79% health — Moderate
Noticeable capacity loss. Runtime shorter than when new. Consider replacement within 12 months.
Below 50% — Replace
Significant degradation. Battery may cause unexpected shutdowns. Replacement recommended.
macOS – System Information and Battery Health
Mac provides battery health information in two ways through System Information for detailed data and through the battery menu for a quick status check:
- Quick check: Hold the Option key and click the battery icon in the menu bar. A status appears: Normal, Replace Soon, Replace Now, or Service Battery
- Detailed check: Hold Option and click the Apple menu → select System Information → click Power in the left sidebar
- Look for: Cycle Count (number of full charge cycles used), Condition (Normal / Service Recommended), and Maximum Capacity percentage on newer Macs
- Alternative free app: Download coconut Battery (free from coconut-flavour.com) shows cycle count, design capacity, current capacity, and battery age in a clean interface
Apple considers a Mac battery to be performing normally for up to 1,000 charge cycles. After 1,000 cycles the battery may hold significantly less charge. The Condition indicator in System Information will show Service Recommended when replacement is advisable.
Android Battery Health Check
Android battery health information varies by manufacturer. Here are the methods that work across most Android devices:
- Dial pad code: Open your phone app, type *#*#4636#*#* — a Testing menu appears. Tap Battery Information to see battery health status, charge level, and battery technology
- Samsung devices: Open the Samsung Members app → Get Help → Diagnostics → tap Battery to run a full battery diagnostic
- All Android: Settings → Battery → Battery Usage shows apps consuming most battery. Settings → Battery → Battery Health shows health status on supported devices
- Google Pixel: Settings → Battery → Battery usage → three-dot menu → Battery health
Android reports battery health in categories rather than percentages: Good, Overheat, Dead, Over voltage, Unspecified failure, and Cold. ‘Good’ is the normal healthy status.
Chrome OS – Battery Information
Chromebooks provide battery information through the browser and through the diagnostics app:
- Open the Chrome browser and type chrome://system in the address bar
- Press Ctrl+F to search — type battery — find the battery section which shows charge level, status, cycle count, and health percentage
- Alternative: Open the Diagnostics app (search in the launcher) → run the Battery test for a full health report
Chromebooks are designed for a battery life of 300 – 500 charge cycles. After this the battery capacity will have noticeably degraded and runtime will be shorter.