[Review] YLP Gekko 1.0 || Samsung LH351D 90CRI, 1x18650 || Excellent UI and Power / Thermal Regulation

The flashlight was sent to me by YLP for review.
Here's the product's link: YLP Gekko 1.0




The Gekko 1.0 comes in a nice cardboard box.



Here's a few shots of the box that list the specifications / features of the flashlight.





Other than the flashlight, the original package contains a head strap, a second magnetic tailcap, a couple of spare o-rings and a user manual.



The YLP Gekko 1.0 comes in a nice metallic dark grey finish.



The body of the light is smooth, while the tail is heavily texturized.



The Gekko 1.0 is operated via an e-switch mounted at the top of the head.



The e-switch is illuminated. The built-in LED is used to indicate the battery's charge level.
( > 70% = Green , 30% - 70% = Red and Green , < 30% = Red )



Some deep heatsinking grooves are incorporated in the head.



The head houses the TIR lens along with the Samsung LH351D 4200K High CRI emitter.



The TIR optics is used to provide maximum light flood.
Here's a shot of the optics in complete darkness.



The manufacturer includes two tailcap pieces.
One comes with a magnet attached to it, while the other one is plain.



The tailcap with the built-in magnet is also a bit thicker, in order to accommodate for the extra space required.
Other than that, both pieces are identical.



Both tailcaps are heavily knurled in order to allow for a better grip.



The tail threads are smooth and arrived adequately lubricated.



It's worth mentioning that the body of the light is glued to the head.
I was able to easily crack them apart using a pair of strap wrenches,

Here's a shot of the interesting looking driver.
The driver is marked as 'Indigo Linear V2.0', while the other markers state '2.7V...4.2V , 1mA - 5A'.
Some programming headers seem to also be available.



The YLP Gekko 1.0 is a headlamp and of course it comes with a 3-piece elastic head band.



A silicone holder with two loops is used to secure the flashlight in place.



The loops are seated into the respective grooves in the flashlight's body.



Of course, the head band is fully adjustable.



The inner part of the band contains a wavy pattern of silicon, which is used to further improve the grip of the band against the operator's head.



User Interface

The YLP Gekko 1.0 comes with a very interesting and advanced firmware.
Its firmware contains multiple operation modes,

The default operation mode comes with the following actions:
Turn on/off: Single press.
Mode cycle: Long press (Low > Mid > High > Turbo > High > Mid > Low )
Moonlight: Long press while off.
Turbo: Double press while off.

Other than the default mode, there are also 3 more advanced UIs which are also user configurable.
Switching between the operation modes is described below.



Here's a short description for each Advanced UI:
Advanced UI #1

  • Stepless dimming.
  • Non-latching maximum mode.
  • Micro-adjustment mode for 1s after setting the "rough" brightness (via stepless dimming).

Advanced UI #2:

  • Extends Advanced UI #1
  • 3 x click for strobe ( with adjustable brightness ).
  • 4 x click for battery check.
  • 4 x click and hold for tactical mode.
  • 5 x click for e-switch backlight on/off.
  • 6 x click for e-switch beacon on/off.

Advanced UI #3:

  • Extends the basic operation mode ( normal stepped modes ).
  • 3 x click for strobe ( with adjustable brightness ).
  • 4 x click for battery check.
  • 4 x click and hold for memory mode on/off.
  • 5 x click for e-switch backlight on/off.

As you can see, the flashlight has a very advanced UI.
Additionally, the user can also enter engineering mode that allows for adjusting a lot more aspects of the firmware (thermal regulation, temperature and battery calibration, stepped mode level adjustment, shortcut re-arranging and a lot more. Feel free to have a look at the Engineering Manual if you're interested.

Output

Here's my output measurements along with the current draw per each output mode.

As you can see, the Gekko pushes 878 lumen at Turbo, which is plenty of output for a headlight.
The mode spacing seems excellent.

Power Regulation

Here's a power regulation graph demonstrating how the Gekko 1.0 responds to different input voltages.

What we can see in the graph:

  • Turbo is fully regulated down to 3.5V
  • High, Mid, Low and Moonlight are fully regulated for the whole span of the battery's voltage.

The flashlight shows signs of great power regulation!


Thermal Regulation

Here's a chart demonstrating the active thermal regulation of the headlight.



What we can see in the graph:

  • The full output of turbo is maintained for 1 minute.
  • Past the one minute mark, active thermal regulation kicks in and slowly reduces the output to keep the temperature in check.
  • High, Medium and Low are fully sustainable for the whole span of the test.
  • While running on Turbo the flashlight never got too hot to the touch. Thermal regulation seems to be working nicely.

Bottom Line

The YLP Gekko 1.0 is an excellent flashlight / headlight.
I'm especially impressed by its excellent firmware and its great power and thermal regulation capabilities

Thanks for the review!

I like the review but I am not so sure the world needs another headlamp.

That looks awesome. How floody is it? Has an anduril like UI with high cri and zebralight style look. It’s exactly what I’ve been looking for.

Is it still the original firmware with all the bugs or was it updated? I was really interested in this light and followed the project closely until the flashlight was released. But Inferion wasn’t able to provide the final firmware in time for the release, so he wrote a quick replacement without the originally planned features and without much testing.

Interesting light. For my money I think I’d still go with a H04 - the quick release clamp of the Skilhunt strap is the best I’ve ever used.

Chinese generic (zebralight clone) host with BAD thermal patch and Russian “eficient” linear driver only for you and only for 50$ shipped.( yes , yes i love YLP )

Could you list what kind of defects where on the original firmware? I can try to replicate them to see if they’re still there or have been fixed.

I’ve listed some of them here: YLP coupon for BLF - #233 by SammysHP

I wished it comes with a pocket clip… :(.

Well, I’ve dissasembled my Gekko after reading about bad thermal design and see what I saw. Nice, right? Almost no conductivity to body. Plus copper plate is attached to 1 mm plate in the head (the one you see with screw holes is not body, it is thin plate inside), without direct contact with cooling ribs outside.
I changed glue to good thermal compound. To my personal feeling - heating changed to faster and hotter, means better thermal conductivity.

Welcome to BLF. Next time buy after reading as many as possible reviews :slight_smile: AEDe review at fonarevka

Changing compound makes thermal exchange much better, actually. The only question - why can't put good compound from factory, since it is the cheapest part of all the product, and emitter is attached with screwes. No need any glue here.
All the rest - it is pretty good flashlight. Light, waterproofed, and convenient hi-cri (to my opinion).

Probably you newer saw good L shape headlamp host? Check skilhunt H04 and new H300. Gekko host looks nice from outside only but inside its trash.

I use mine pretty often, so far works fine, when it cooks its own led, then will take it apart and play with it, maybe even fix it, or i’ll test my aim at 100 yards with my .44mag lever action.
It IS a shame, they went thru all those troubles to design and manufacture pretty decent light, even if their driver is not most efficient or advance, but all of it seems to be negated by simple “saving by a shortcut”, simple QC and maybe an extra step to ensure proper heat path would make this light actually reliable in a long run. go figure,

Just google "teardown skilhunt XXX" or another flashlight and you'll see almost any popular model from inside without buying it.

Fixed photos by the way, didn't upload for some reason.

Gekko is not that bad, but yes - even the cheapest Convoy has better machining/finishing.

It is exactly what I mean - so much effort to design and manufacture, and such a poor QC. Even the cheapest Convoy has more and better compound. I spent 8 years in China working in trading and QC of our orders. It is so simple to hire an expat there and let him/her check every 20-30th unit or even less frequent. Even simple presence of "inspector" helps a lot )))

And where did the heat go with bad thermal compound?) It’s just self-suggestion. The only difference is led temperatuture and corresponding decreasing of luminosity while led warm up, and you can not see it without instruments.

This is a wrong question. Not where, but how. Heat dissipation affects emitter lifetime. I'm not going to discuss it, just wanted to let others know about this issue. And I posted same at fonarevka, if you're interested http://forum.fonarevka.ru/showthread.php?t=45417&page=34

It is right question. You just not qute understand phisics of this process. I am not interesting in your subjective feelings, thanks, I have thermal camera and I can measure everything that can be interesting.

I also not going to discuss that. I just let other to know that you subjective feelings of issue deviate from reality.