Platform instructions
Find battery condition and capacity information on Windows, macOS, and Linux. Use the analyzer when a Windows report or matching Design Capacity and Full Charge Capacity values are available.
Windows guide
Windows can generate an HTML report containing installed battery information, capacity history, usage data, and estimates when those values are reported by the system.
Open a command-line window from Windows Search. The battery report command may work without elevated access; managed devices can apply different policies.
The standard command saves the report in the current command-line path:
powercfg /batteryreportTo place the report on the current user's Desktop with a predictable filename, use:
powercfg /batteryreport /output "%USERPROFILE%\Desktop\battery-report.html"
Open the path shown by Windows. When the Desktop command above is used, the file should be named battery-report.html on the current user's Desktop.
Select Upload Windows Report in the analyzer, choose the HTML report, and review the extracted capacity results. The API must still validate the file on the server.
macOS guide
Apple provides a built-in Battery Health condition. Raw Design Capacity and Full Charge Capacity values are a separate type of information and may not be available on every Mac or macOS version.
Open the Apple menu and choose System Settings.
Select Battery in the sidebar, then review Battery Health.
macOS may show a condition such as Normal or Service Recommended. Follow Apple's service guidance when the system reports a service condition.
The following command displays the power information made available by System Profiler:
system_profiler SPPowerDataTypeDo not enter a percentage such as Maximum Capacity as a raw Design Capacity value. Manual calculation requires two compatible capacity measurements in the same unit.
Use manual entry only when both raw capacity values are available from a reliable source. When macOS provides only its built-in health condition or a percentage, use that information directly rather than constructing an unsupported conversion.
Linux guide
Linux distributions and battery drivers expose different fields. Start with UPower, then inspect the system power-supply directory when necessary.
On supported UPower versions, this requests parameters for battery devices:
upower --batteryTo inspect a particular device, first enumerate the object paths:
upower --enumerateCopy the battery object path from the output and pass it to the information command. The following path is an example and may not match your system:
upower --show-info /org/freedesktop/UPower/devices/battery_BAT0Look for matching fields such as energy-full and energy-full-design. Field names and availability depend on the device and driver.
List the available power-supply devices:
ls /sys/class/power_supply/Replace BAT0 with the battery directory found on your system. Where energy fields are available, inspect:
cat /sys/class/power_supply/BAT0/energy_fullcat /sys/class/power_supply/BAT0/energy_full_designSome drivers use charge_full and charge_full_design instead. Use values from the same field family and do not assume that charge and energy units are interchangeable.
Enter Full Charge Capacity and Design Capacity only after confirming that both values use the same unit. Preserve the raw result even when the calculated percentage is above 100%.
Use manual capacity entryCapacity terminology
Battery health is meaningful only when the numerator and denominator represent compatible capacity measurements.
Meaning
The reported capacity the battery was designed to hold when new.
Calculator use
Used as the denominator. It must be greater than zero.
Meaning
The amount the battery currently reports it can hold at a full charge.
Calculator use
Used as the numerator. It cannot be negative.
Meaning
Often presented as a percentage relative to a new battery.
Calculator use
Do not enter a percentage as an mWh or mAh value.
Meaning
A count related to accumulated battery discharge and recharge usage.
Calculator use
Useful context, but not part of the capacity formula.
Formula
Battery Health Percentage = (Full Charge Capacity ÷ Design Capacity) × 100
Interpretation
Capacity values are supplied by the operating system, battery controller, firmware, and driver. Missing or unusual values do not automatically establish that the battery is defective.
Calibration, replacement batteries, firmware behavior, and manufacturer reporting can affect the displayed values. Review the calculated percentage together with runtime, charging behavior, shutdowns, temperature, and physical condition.
Safety
Stop using and charging a battery that is swollen, leaking, punctured, emitting an unusual odor, or becoming unusually hot. Follow the device manufacturer's handling and service instructions.
The analyzer provides general capacity information and does not replace inspection by the manufacturer or a qualified repair professional.
Questions and answers
Use the Windows guide when you can generate battery-report.html. On macOS, start with Battery Health in System Settings. On Linux, start with UPower. Use the analyzer's manual mode only when you have both Design Capacity and Full Charge Capacity in the same unit.
Microsoft documents the powercfg /batteryreport command without stating that administrator access is always required. Device policies can differ, so follow any access requirements applied by your organization or Windows installation.
No. A percentage such as Maximum Capacity is not the same measurement as a raw Design Capacity value. Do not combine a percentage with an mWh or mAh value in the manual calculator.
Battery drivers expose different fields. Some systems provide energy_full and energy_full_design, while others provide charge_full and charge_full_design. Use values from the same field family and the same unit.
Keep the reported result visible. Values above 100% can occur because of calibration, replacement batteries, firmware behavior, or manufacturer reporting. The visual meter may be limited without changing the source calculation.
No. Capacity percentage is an informational measurement, not a complete hardware or safety diagnosis. Stop using a battery that is swollen, leaking, physically damaged, or unusually hot and follow the device manufacturer's safety guidance.
Operating-system interfaces can change. Use the platform provider's current documentation when your device does not match these instructions.
Battery capacity analyzer
Upload a supported Windows report or enter compatible capacity values manually to calculate the reported battery health percentage.