Peak Power vs Sustained Power in UV Flashlights
A UV flashlight can make a great first impression and still behave very differently after ten or thirty minutes. That is why UV Geek does not treat a cold-start reading as the whole performance story.
The Metric We Use: Output Retained
Our current LS128 sustained-output protocol runs for 32 minutes. The first 5 seconds are excluded. The stabilized 0:05-0:15 average becomes the 100% baseline. The 10-minute checkpoint is the 9:55-10:05 average, and the 30-minute checkpoint is the 29:55-30:05 average.
Each percentage below compares a light with its own stabilized baseline. These percentages measure stability over time. They must not be used as an absolute cross-model power ranking.
| Light tested | Output Retained at 10 Minutes | Output Retained at 30 Minutes |
|---|---|---|
| UV Geek Atlas 365 | 96.3% | 89.2% |
| UV Geek Scout 365 | 88.5% | 81.1% |
| UV Beast V3 365 | 41.1% | 37.9% |
| UV Beast V3 385-395 | 41.0% | 38.9% |
| UV Beast V3 Mini 365 | 73.8% | 67.7% |
What the Current Results Show
In this set of official LS128 runs, Atlas retained 96.3% at 10 minutes and 89.2% at 30 minutes. Scout retained 88.5% at 10 minutes and 81.1% at 30 minutes. The tested UV Beast V3 365 retained 41.1% at 10 minutes and 37.9% at 30 minutes.
That tells you how each tested light held its own output. It does not tell you that Atlas had more absolute UV than Scout, or that one raw LS128 number should be divided by another model’s raw LS128 number.
For Cross-Model Power at Distance, Use LS135
Absolute comparisons between models are handled separately with LS135 distance irradiance after a standardized 10-minute burn-in. Those readings are reported in µW/cm² at 10, 20, 30, 40, 50, and 60 feet where a full distance series exists.
Learn more: How We Test 365nm UV Flashlight Output
Why Sustained Output Matters
A rental inspection, beach search, mineral hunt, or yard scan lasts longer than the opening seconds. If output falls sharply as the light warms, the search changes while you are still using the tool. Retained-output testing makes that behavior visible.
Retention Is Not Runtime
A light can stay switched on long after its UV output has declined. Runtime answers how long the light operates. Output retention answers how much of its stabilized starting output it still holds at a stated time. Keep those claims separate.
Learn more: Why Runtime Claims on UV Flashlights Can Be Misleading
Bottom line: a startup number is a snapshot. Output retained at 10 and 30 minutes shows how the tested light behaves once the search is underway. Use LS128 for stability over time and LS135 for cross-model irradiance at distance.