Windows report method
Generate battery-report.html
- 01
Open Command Prompt or Windows Terminal.
- 02
Run the following command:
powercfg /batteryreport - 03
Locate the generated HTML file and select it in the upload method above.
Battery capacity analysis
Battery Health Analyzer
Upload a Windows battery report or enter Design Capacity and Full Charge Capacity manually to calculate the battery's reported health percentage.
Battery analyzer
Choose how to provide battery capacity data
Upload a Windows battery report or enter capacity values manually. Use one method at a time.
Calculation method
How battery health is calculated
The calculation compares the battery's current reported full charge capacity with its reported design capacity.
Battery Health Percentage = (Full Charge Capacity ÷ Design Capacity) × 100
Design Capacity must be greater than zero. Full Charge Capacity cannot be negative. Values above 100% remain visible rather than being silently changed, although the visual meter is limited to its display range.
Manual method
Enter capacity values directly
Use manual entry when the required values are already available from Windows, macOS, Linux, firmware, or another device utility.
- Design Capacity
- The capacity the battery reports it was designed to hold when new.
- Full Charge Capacity
- The capacity the battery currently reports it can hold when fully charged.
Result interpretation
General battery health ranges
These classifications provide context for reported capacity and do not replace a complete inspection of battery behavior or condition.
| Health range | Classification | General meaning |
|---|---|---|
| 90% and above | Excellent | Reported full charge capacity remains close to the original design capacity. |
| 80% to 89% | Good | Some capacity loss is present, but reported capacity remains relatively strong. |
| 70% to 79% | Fair | Capacity loss is noticeable and available runtime may be reduced. |
| 60% to 69% | Weak | Reported capacity has declined substantially compared with design capacity. |
| Below 60% | Poor | Reported capacity is significantly below the battery's design capacity. |
Accuracy and limitations
What the result can tell you
The result shows the relationship between two reported capacity values. It can help indicate how much reported capacity remains compared with the original design capacity.
What the result cannot confirm
- It does not diagnose every charging, electrical, thermal, or physical battery problem.
- It does not guarantee remaining runtime under a particular workload.
- It does not provide a definitive replacement decision.
- Calibration, firmware, battery age, replacement batteries, and manufacturer reporting can affect the values.
Questions and answers
Battery analyzer questions
Which battery report file should I upload?
Upload the battery-report.html file generated by the Windows powercfg /batteryreport command. The analyzer interface accepts HTML files up to 2 MB, while the API route must independently enforce its own server-side checks.
Can I calculate battery health without uploading a report?
Yes. Select the manual method and enter Design Capacity and Full Charge Capacity using the same unit, such as mWh or mAh.
How is the percentage calculated?
Battery Health Percentage equals Full Charge Capacity divided by Design Capacity, multiplied by 100.
Does a low percentage confirm that replacement is required?
No. The percentage is an informational capacity indicator, not a complete hardware diagnosis. Actual runtime, charging behavior, temperature, physical condition, and manufacturer guidance should also be considered.