The flashlight was sent to me by YLP for review.
Here's the product's link: YLP Sherp S15
The S15 comes in a hard cardboard presentation case.
The flashlight along with the included battery are seated into foam.
The box also includes a wrist strap, 2 replacement o-ring and a manual.
The S15 comes with a flat black anodization and is e-switch operated.
Its body it totally smooth except from some heat-sinking grooves on the head.
Opposite to the e-switch, there's the secondary XP-G3 led that provides a very floody beam.
The secondary emitter comes with no reflector and is covered by a semi-transparent plastic which is used to enhance the floodiness of the beam.
The e-switch comes with a bright orange rubber cover and sits almost flush with the rest of the body.
It's worth noting that there's an indicator LED installed into it that will glow in red once the battery is low.
The head houses the primary emitter, which is a Warm Cree XM-L2, along with the TIR lens.
The head can be disassembled easily by untwisting the metal bezel.
And here's a closer look at the TIR optic.
The optic creates a wide, artifact-free beam.
The tail houses the copper spring.
The S15 comes with anodized threads, which means that it can be mechanically locked out.
As with most flashlights from YLP, this one also comes with an 18650 cell.
The cell is branded with 2600mAh of capacity and has built-in charging and protection.
User Interface
The user interface of the S15 is adjusted to its dual emitter setup.
Here's all the supported actions:
Turn on/off (Main emitter): Single press.
Turn on/off (Side emitter): Double press for ON, single press for OFF.
Mode cycle: Long press - Main emitter (Low > Mid > High > Low > ... ) , Side emitter(Low > High > Low > ...).
Moonlight: Long press while off.
Turbo: Double press and hold.
Turn on/off Memory: Long press for 15secs. 1 blink = OFF, 3 blinks = ON
It's worth noting that the side emitter works independently from the main emitter.
This means that both emitters can light up simultaneously.
Output
I took my output measurements using the include YLP-branded 18650 cell.
Here's a table with the measured output along with the respective power draw.
As you can see, the advertised max output is pretty close to what I measured (867lm)
I also measured the parasitic drain at 51μΑ, which is very good.
Thermal Regulation
Here's a thermal regulation graph I created.
What we can see in the graph:
- The max output is sustained for 2.5 minutes.
- After the 2.5 min mark, the output gradually steps down to 670 lumen.
- The stepdown output if fully sustainable.
- The output looks very well regulated.
- The whole time, the head of the flashlight never got too hot to handle.
Outdoor beamshots
For the last part, here's few outdoor beamshots.
At 10m
At 30m
At 35m