AN74 / PREPARE FOR TOMORROW
How to read a flashlight runtime graph: peak, plateau and useful duration
To understand flashlight runtime, look at the output maintained over the period that matters to you. A bright opening peak and a large hours figure on a specification sheet do not, by themselves, tell you how long the light will meet your needs.
This guide explains how to read an existing graph. It contains no AN74 hands-on test, and none of the example numbers describe a commercial product.
Start with the axes and legend
- Time: check whether the horizontal axis uses minutes or hours. Similar-looking graphs can cover very different periods.
- The plotted quantity: check whether the vertical axis shows lumens, lux or a relative percentage. Do not mix these scales. A line at 100% does not, on its own, tell you an absolute light output.
- The mode: identify the line for the setting you intend to use. Maximum output and maximum runtime may refer to different modes.
- Conditions: look for the exact model, battery, setting, date and measurement method. Record missing details as unknown.
Follow the whole curve
Read from left to right. A peak is a brief section above the rest; a plateau is a relatively steady section. A gradual decline and a final switch-off tell different stories. Before comparing lights, note the output at the time you expect still to need them, rather than stopping at their initial maximum.
A visible drop does not, by itself, diagnose a faulty battery or explain why output changed. The graph shows a pattern; explaining its cause requires the tester’s procedure and observations.
A fictional comparison
These numbers are invented for teaching. In this simplified scenario, A supplies 1,000 lm for two minutes, then 100 lm until minute 180 before switching off. B supplies 300 lm for 90 minutes, then switches off.
| Profile | Start | At 60 min | Time at ≥ 200 lm |
|---|---|---|---|
| A | 1,000 lm | 100 lm | 2 min |
| B | 300 lm | 300 lm | 90 min |
The 200 lm threshold is an arbitrary calculation aid, not a standard or a recommendation for reading or walking. At that threshold, B meets the chosen level for longer, even though A stays lit for longer overall. Choosing a different threshold would change the comparison. Beam shape, distance and the actual task still need separate consideration.
FL 1: check the edition too
In its February 2026 announcement, PLATO describes ANSI/PLATO FL 1-2025 and its new method for measuring short-duration elevated brightness, often called turbo or boost. Do not assume an older specification sheet follows that new method. Look for the edition and procedure actually declared.
A reference to a standard is not, by itself, proof of independent certification. PLATO separately describes the UL S8001 performance-verification programme. We claim no certification for the lights in our selection.
Keep a short reading record
- My task and required duration: ______
- Model, variant and plotted mode: ______
- Vertical-axis unit and horizontal time span: ______
- Output shown at my chosen time: ______
- Known conditions and missing information: ______
- Test author, date and link: ______
Limit your conclusion to the evidence: “this test shows this output, in this mode and under these conditions”. One curve guarantees neither your exact runtime nor long-term durability.
Apply this to the AN74 selection
The Wurkkos FC11C dossier brings together specifications and credited external reviews. Use it to find a source and inspect its legend; do not transfer the fictional figures above to the product. Define the task first with our power-cut lighting guide. Other formats appear in the headlamp selection and the LT1S lantern dossier. These links document candidates and do not announce that orders are open.