Windows Battery Report Interpreter
Turn a Windows battery report into the one number it buries: capacity remaining.
What you paste
Parsed in your browser — never uploadedHow this reads your output
The report Windows generates contains the two numbers that answer the question people actually have — the capacity the pack was built with, and the capacity it charges to now — and buries them above five hundred lines of charge history. Both are read out and compared. A full-charge figure at or above the design figure is reported as as-new rather than as negative wear, which is what a naive subtraction produces and what makes other tools look broken on a new laptop. Below that, the bands follow the industry convention that a pack is at end of service life around 80% of its design capacity, which is the figure most manufacturers use for warranty purposes.
What the results mean
- Design capacity
- What the pack was manufactured to hold, in milliwatt-hours. Fixed for the life of the battery.
- Full charge capacity
- What it charges to now, as measured by the machine. The gap between the two is the capacity that has been lost.
- Capacity remaining
- The second figure as a percentage of the first. Above 80% is ordinary; below 50% means the machine is effectively tethered to mains power.
- Cycle count
- Full charge-discharge equivalents. Most packs are rated for 300 to 1,000. Frequently absent, because many manufacturers never report it.
Common problems and fixes
- No capacity figures were found
- Open the saved report file in a browser, select the whole page and paste it. The figures are near the top, above the long charge-history tables.
- The percentage is higher than the machine claims
- The report reflects the last measurement the firmware made. A pack that has not had a full charge and discharge in months can report a stale figure.
- Runtime is terrible but capacity looks fine
- Capacity is not the only variable. A cell that has gone high-resistance sags under load, and a machine that shuts down at 40% is showing that rather than lost capacity.
- The pack has swollen
- Stop using the machine on charge and replace the pack. A swollen pack — a trackpad that no longer clicks, a case that will not sit flat — is a hazard rather than an inconvenience, and it should not be carried on a plane.
Frequently asked questions
What counts as a worn-out laptop battery?
The usual convention is 80% of design capacity — the point most manufacturers treat as the end of warranty life, and where the runtime loss becomes obvious rather than arguable. Below 50% the machine is effectively a desktop. Neither is dangerous; both are reasonable moments to replace the pack.
How do I get a battery report from Windows?
Windows generates one through its own power configuration tooling and saves it as an HTML file, which opens in any browser. Open it, select all, and paste it here. The report is generated by the machine itself — this page has no way to measure a battery, only to read what Windows already measured.
Does cycle count matter more than capacity?
Capacity is the number that affects you; cycle count is context for it. A pack at 300 cycles with 85% capacity has aged well, and one at 300 cycles with 60% has been kept hot or held at full charge — which damages lithium cells faster than cycling does. Where the count is missing entirely, capacity alone still answers the question.
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