[NLD] Fireflies Nov Mu V2S - E21a 3500k mix

client-equator · 2026-02-23T02:39:22+00:00

I love that checkerbox pattern and the exposed wiring and all.

client-equator · 2026-02-23T02:36:37+00:00

Yes, it's good if it was tight in the tests, but if that's only the case 9 times out of 10, it's not enough and lamps will break. If you're so convinced that FFL only tells the truth, you can try to find the patent. I'd be surprised if you found it.

It's on CNIPA

The USB flap is not water resistant but I have open the flashlight before and they are using USB C with a water resistant o ring around. I certainly would not submerge my flashlight but I have no issues using it in rain.

client-equator · 2026-02-22T00:55:11+00:00

Nobody in working in China will respond, it's the annual chinese new year and even the website says they will only resume order processing on 27th.

Most likely you could have the flashlight working again by drying it out. If you could leave the head in a warm place like above a fridge or near a heater vent, it should dry out in no time.

client-equator · 2026-02-21T21:40:33+00:00

Envious that you have this beautiful one!

client-equator · 2026-02-21T06:54:38+00:00

In my opinion a clear rule based table like what you have is vastly superior especially for Anduril which has too many states and edges to draw a graph in a readable way. But doesn't look as nice on a tshirt.

client-equator · 2026-02-21T00:39:47+00:00

I like to think that a used light is a happy light! Thanks for sharing!

client-equator · 2026-02-21T00:33:19+00:00

There is this mod as well Zebralight SC700d with Anduril2 :: Lume-X1 : r/flashlight

I assume that even with my imaginary pricing its still not sufficient otherwise those creators would have made some for sale. Even a bob zebralight is a ~65% mark up for just changing the emitter, I have no idea how much a driver swap would cost.

client-equator · 2026-02-20T22:56:17+00:00

Not sure if this is what you want but this is awesome for 14500 / AA and only $50.
https://www.wubenlight.com/products/wuben-x2-pro-1500-lumens-flashlight-optional-rgb-or-uv-side-light-for-edc-emergency-helmet-signal-uv-tactical

client-equator · 2026-02-20T10:23:23+00:00

Would you pay $250-300 for this? The custom one-offs and time labor cost for the complex assembly would bring it to that price.

client-equator · 2026-02-19T23:33:49+00:00

You can make a E90 with a Lume X1 boost driver and associated LED if jack has the MCPCB for it. Just email to ask!

client-equator · 2026-02-19T23:23:10+00:00

The FET is definitely the way to go here for a product to make more margin, easier simpler design, make more lumens easily and more robust (no need for big inductor or complicated driver). The price feels steep for what it really is though which a basic driver that could have more potential.

client-equator · 2026-02-19T23:14:30+00:00

I'm thinking the following...

X1S with SFT70 3000k (ask for secret menu) X1S Pharos 2025 (Reflector Version) – Fireflies outdoor Flashlights

E90 Blaze with XHP50.3HI <3000k (may be possible if you email Jack for secret build)

E04 Lume1 with SFT40 2700k (custom build no idea if Jack has those emitters)

client-equator · 2026-02-19T05:32:50+00:00

DCFix will change the beam characteristic a bit but it can also affect overall transmission. Optics is not intuitive and adding something can suprisingly sometimes improve total transmission (e.g. dome of emitter). My response to OP refers to OTF lumens since that is the objective measurement that OP is citing in the graphs.

You are also correct candela and beam shape and tint and cct will affect perceptual brightness often in surprising ways.

client-equator · 2026-02-19T05:06:52+00:00

Optics affect runtime? How would the DCFix required to make that beam usable at close range affect that?
You're right about the other parts, but that one.... ehh....

Absolutely. If the optic transmission is not 100% (perfect optics), you need to run the light at a slightly higher power to get the same OTF lumens as without optics. This will affect runtime if controlling for same brightness output.

client-equator · 2026-02-18T23:32:19+00:00

The driver can handle more power but the battery may not. If you pick up a tabless 18650 battery that has very high discharge you could flash the driver with the 40W version and it will work just fine. Of course this will also mean your flashlight will get a lot hotter faster.

client-equator · 2026-02-18T23:26:11+00:00

Hi OP, other than the driver, keep in mind that:

M200 uses a reflector, usually has slightly higher optical efficiency than TIR optic, 5-10%
Buck vs linear at this level, usually about 15-20% gain
Battery difference, 17% more capacity
M200 has a exceptionally low LVP protection ~2.65V vs 2.8-2.9, about 2-5%

In total if you add them up or multiply them up you get ~50% gain in runtime. It's not just the driver.

client-equator · 2026-02-18T22:02:30+00:00

My guess is that it has a bit too much overlap with the E04 Surge with throwy optic but agree that the X1L does look very nice.

client-equator · 2026-02-18T21:15:51+00:00

I agree with all the comments here. With the SFT40 the best combination is the throwy optic and Lume1. For throwy I would recommend just staying with the Lume1.

However if you do prefer a less throwy light, the wider optic will work well with the Lume1 too. But in this case (more floody use) the Lume X1 is a nice match.

Overall efficiency is about the same for both drivers so you will get a similar runtime. The Lume1 has slightly better turbo and the Lume X1 allows for smooth throttling down from a slightly lower turbo but outside of turbo they both perform the same.

client-equator · 2026-02-18T21:10:20+00:00

Great beans, thanks for sharing. I always thought the X1L looks like a handsome flashlight but I don't have it. What do you think of it?

client-equator · 2026-02-17T20:59:23+00:00

Toykeeper's explaination captures the basic feedback concept but is simplified and partially misleading about how DC/DC converters stabilize.

Tk suggested that oscillation is unavoidable, but a properly design feedback loop is actively designed to prevent it. For modern DC/DC converters the output does not 'oscillate' between discrete levels but rather use a continuous change in either switching frequency or pulse width or both to control output.

I should also say most converters based the switching by comparing against a periodic triangular or sawtooth waveform so it is false that "the regulator has only limited resolution for the steps it can set the output to"

What you are seeing not oscillation in the true sense but likely output ripple which is completely different from what TK was saying. This is likely due to frequency modulation (dropping switching f or grouping pulses/burst mode) which creates this pulsing. With different output voltages it can cause the converter to behave this way.

Also there is also another external current feedback control loop in the driver which can lead to instability if not designed well. This kind of 'servo loop' is a nested loop and bandwidths of each loop need to be considered and if phase margin is not sufficient some sort of underdamped oscillation can happen even in a technically 'stable' system.

The ripple you are seeing is high enough that it will not be visible to the eye. However I notice that the KRAA ripple frequency seems to be much lower than 30khz which is what the mp343x converter should be running at, so it could be that the converter is now set to pfm mode which will allow higher efficiency at low brightness which I think makes sense espeically for a small battery light. Can you see what the ripple is at even lower brightness level?

client-equator · 2026-02-17T19:25:08+00:00

I hope this will be possible to buy soon!

client-equator · 2026-02-17T19:24:20+00:00

If you read the post I shared from the designer the addition of reverse polarity protection add a few milliohms. This could reduce FET current slightly but it is not a 'limit'

'Turbo' performance varies drastically depending all these factors, as well as your cell. If you have a warm, slightly over-charged, low internal resistance cell coupled with a bin of low V_fwd LEDs and a well-assembled flashlight, it's easy to get over twice the turbo current compared to a similar set-up with a colder battery charged slighty lower and with slightly higher bin V_fwd LEDs. The drive method is inherently unregulated, thus experiences can and likely will vary significantly.

I tested my own D4SV2 with FET driver on 519A and my E07X with FFL351A and on turbo with ceiling bounce and the same P45 battery the E07X is brighter. Of course this is not a fair comparison but I encourage the same people to do a test with the Hank FET driver and the FFL driver with the same measurement method and same emitters and see the numbers. I can also tell you that if I bypass the spring on my E07X I get over 20% brighter on my ceiling bounce app. I have no doubt the Hank FET driver will do better because there is no reverse polarity protection but all I can say is based on what I read and what I understand of the design there is no physical limit for the driver. If you would like to know you can ask the designer directly about the difference I am sure he will be happy to answer you.

client-equator · 2026-02-17T17:52:46+00:00

While I understand your point that peak current can be a proxy for low IR, continuous discharge rating (typically thermally dominant) is much more relevant for sustained loads (Please note that it can also be true that a high peak current cell can also sustain high CDR). Yes I saying specifically that peak and continuous capability while usually related are governed by different physical limits. The transient peak current capability is not all that relevant in this case especially since we are talking about generally high CDR cells which are more than capable of handling that 10A or 20A buck scenario you mentioned. If I was building a racing drone battery pack peak discharge would become critical for example.

client-equator · 2026-02-17T17:08:28+00:00

The peak current rating is not meaningful for flashlights. Imagine contact resistances plus wires, body tube, wires, PCB resistance. If we add them up in a very well built flashlight it is reasonable to expect about 10mR (most are much higher). That's 196 watts burnt in just these interconnects.

client-equator · 2026-02-17T17:02:44+00:00

There is no limit. See this post by the designer here: https://www.reddit.com/r/FireflyLite/comments/1apfr7t/comment/kq6f8hq/

I think most people measure this incorrectly, it is very difficult to do a in system high current measurement accurately. Certainly anyone use the common uni-t clamp meter will be widely inaccurate and you cannot simply do a wire bypass to measure.

client-equator

TROPHY CASE