TK's Emisar D18 review -- 3x18650 photon grenade

Is Nichia producing 219B’s again (including 4000K & 4500K)?

Very detailed review… thank you!! :beer:
This one looks like a ’must have’.

What is it that you dislike about buck, boost and constant current drivers?

They don’t give maximum output, of course. Lol

Nice review TK. :sunglasses:

Can’t wait for mine to arrive! :heart_eyes:

Is it an upgrade? It depends. Let’s go point by point:

The size of D18 vs M43 is six of one, half a dozen of another. One is a little longer, the other is a little wider. Overall volume is similar.

But let’s measure it anyway…

  • M43: ~242 cm3 ((40.5 x 63) + (57.4 x 50.7))
  • D18: ~213 cm3 ((43.0 x 58) + (59.5 x 46.1))

So… I’d say the D18 is about 13% smaller.

Depends on what you’re measuring:

  • Energy capacity: With 4 cells, the M43 has more energy capacity than the D18’s 3 cells. All other things being equal, M43 should have 33% longer runtime.
  • Overall efficiency: M43 is more efficient on medium modes, and thus should have longer runtime. However, D18 is more efficient at the lowest and highest modes. I don’t know where the graphs intersect, but I expect M43 has longer runtime at most levels except for maybe 20 lumens and below. Its low-mode efficiency is pretty bad.
  • Maximum runtime: The M43’s longest-running mode lasts about 35 days. The D18’s longest-running mode lasts about 8.5 months.
  • Standby time: The M43’s standby drain is more than twice as high as D18, so it has shorter standby time.

I’m not sure if this refers to current regulation or thermal regulation, but I’ve measured both.

In my testing, the M43 was not stable at any level… even low modes. It sags while it’s in regulation, and then it sags more when the cells are too low for regulation. But the D18 maintains mostly steady output in its regulated modes until the cell voltage is lower than emitter Vf.

To compare directly, I tested the current regulation in both lights. I set them to an easy level which any battery should be able to handle — about 120 lm. Then I connected them to a bench power supply and turned the dial to change the voltage, and I recorded the lumen output over time. Voltage went from 4.2V to 3.0V. Here’s how that went:

In terms of thermal regulation, the M43 I tested had pretty unstable output. The D18 isn’t completely stable there either, but it seemed at least a little less volatile than the M43.

I tried running both lights on turbo, to measure the thermal regulation. This is how the D18’s graph looked… It stayed at about 45 C throughout the test:

… and this is how the M43’s graph looked. It was about 60 C to 65 C during this test:

Both lights require high-drain cells to get full turbo output. Neither light requires high-drain cells for low and medium modes. Both are completely fine with old low-amp cells, as long as you don’t want more than a couple thousand lumens.

The boost driver is certainly fancier. It’s more efficient by a few percent, except on very low and very high modes. It balances output better across emitters of slightly different Vf. It doesn’t have PWM. However, it also has drawbacks… like increased price, more difficult thermal management, increased size, decreased efficiency on very low and very high modes, a smaller output range, etc. Both are good, but in different ways. I consider it another “six of one, half a dozen of another” comparison.

A good boost/buck driver is a wonderful thing. I really like DEL’s buck driver in the BLF GT. I love how steady my Zebralights are. I can’t really say the M43 has a good boost driver though… it has really unusual behavior.

This may be a cultural difference, but in much of the world, simple is good. It is not “simple” as in “simpleton”, meaning unintelligent… simplicity is robust and elegant. Complexity is a negative trait, to be avoided when possible.

I’ve tried to make the firmware simple and easy to modify, even for people who don’t normally write code. The best possible code is that which, when someone reads it, they immediately understand it. Ideally they should even go “Duh, why didn’t I think of that?” because it’s so obvious. This isn’t always possible, but it’s a good ideal to strive for.

The M43 is a clear winner here. I was hoping the D18 would have a button light, but it doesn’t. However, the driver has pads to connect one, and the firmware supports it… all that is needed is to physically add the light and connect it.

Huh?

Compared to the M43, the D18…

  • … is throwier.
  • … has a wider output range, going both much lower and much higher.
  • … is less likely to activate by accident.
  • … is easier to use.
  • … has a bunch of extra modes and firmware functions.

Yeah, that is an accurate description which in no way misrepresents anything. :wink:

I measured my M43 and D18. The M43 made about 4950 lm, while the D18 made about 14500 lm. But these numbers are probably not very accurate; I should have some more accurate measurements in a few days.

Not really. The M43 does not have a reputation for being mod-friendly.

So… Is the D18 an upgrade? Depends on your personal preferences. For me, it’s an upgrade.

The M43 was good. I liked the M43 enough to buy it at full price. It was stubby and cute and solid and bright. But I didn’t like its Carclo 10507 beam shape, the driver never really worked well on mine, and I really disliked its UI. The UI in particular held back the M43; it was probably the thing people complained about most.

The D18 fixes all these things.

On a related note, has anyone else noticed that Inferion recently made a linear driver with a ramping UI called Indigo v2.0 Lite? It looks interesting.

They’re the only unpopulated pads on the driver — G, I+, and R4.

The beams of D4S (XP-L HI) and D18 (SST-20) look almost identical, actually. The hotspot is the same size, the spill is the same size… except I think D4S has a somewhat brighter hotspot with less-bright spill, while the D18 has a somewhat less-bright hotspot with more lumens in the spill area.

So the beams look pretty similar, but the D4S gets more throw per Watt and the D18 has a more useful spill area. It’s weird that they look so similar when the D4S has a cd/lm value twice as high.

Something does not agree. As if the D18 had a similar beam of light to D4s with XP-L HI it would mean that it had about 125,000cd, and Hank would give 65,000cd. This means that the D18 shines wider or the measurements are from the ass. So far, however, Hank’s measurements were quite precise so? I will find out how I will buy one.

It sounds like the extra lumens in the spill mean less lux in the hotspot for the D18, allowing it to still have roughly the same apparent size to the hotspot.

@TK: Thanks for your review and the very detailed post no. 43!
Does the driver of the D18 have over-discharge protection?

Concerning the “throwyness”:
The Meteor M43 has more throw at a given level of output because of its larger optics.
D18 with SST-20: 65,000cd / 14,000lm = 4.64cd/lm
M43 with SST-20: 52,000cd / 8,200lm = 6.34cd/lm
The Meteor should be able to hold around 2500-3000lm steady with 15,840cd to 19,020cd.
The D18 holds 2000lm steady with 9280cd.

Only in the first 30s of operation the D18 is actually brighter and throws further.

I think the throw is very important with these lights. I have found my Meteor with partially de-domed LEDs to have the most practical beam of all my lights for walking in the woods. It has a very wide spot with decent throw and a super wide outer spill (a benefit of the Carclo optics). This means you stumble less because you see things on the ground from the corner of your eyes and you don’t need to move the light so much when walking.

In my eyes the biggest advantage of the D18 is the smaller diameter. It’s more ergonomic. I can also understand that its U.I. is more popular.

So the moonlight (low) mode seems to be much lower on paper than the D4 and D4S, is that right?

Pavio, I am not so young anymore. Most of my life a flashlight got dim as it’s cells grew discharged, so to me that is how it is supposed to work. As my work with the flashlight progresses, I am constantly reminded of how much longer the flashlight will work for me by the ever decreasing output. I can easily judge when to take a break and replace cells. Being very forgetful by nature, all my life, when I am involved in work I have little time sense, so the flashlight itself can help to remind me to take a break, get a drink, food, whatever.

I also do not like pulling more amps out of a nearly dead cell. The regulated drivers do this to maintain brightness as the cell discharges, the lowest current is pulled from the most capable charge level, the highest current is pulled from the least capable charge level. I do not like this. I do not like subjecting this (what I think of as abuse) behavior to my cells. I would rather hammer them down with massive current draw right from the beginning. :slight_smile:

And like Jason said, the regulated driver is not capable of maximum output from the beginning. I like Turbo. Not quasi high. Call it a Texas thing. Bigger is better, however you want to look at it my preference lies in the cheaper to make FET drivers. (I can build this for around $5, and I have built hundreds of them for the ~600 lights I have modded as well as for several other folks here.) I have a prototype boost driver or two, and have been told their price level, this is not something I would want to use in quantity, obviously a 5x greater cost would get ineffective very quickly. I don’t mind using them sometimes, but I do find it worrisome the resulting low discharge level if I forget the time it’s run and take the light to the cut-off point. I normally charge my cells when they still have a comparatively high charge, seldom taking a cell down to 3.7V… much less 2.5V! (or even less, as some regulated drivers will do)

I like what I like, I have no need to sell anyone on my preferences or ideas… I use my lights for my own purposes and as I have found over the past 6 years or so, a large part of my purpose is to tweak a light for all it’s worth. I have reason to mod lights for nothing more than the time it kills, the effort it requires, or the final number it can produce… so whether I use the modified light or not isn’t where the relevance lies in the end. This is most likely not how the larger public views things. It is, however, a large part of why I mod. Like asking a mountain climber why they climb mountains and they say “Because I can!”. In great part, for me, it’s like that with flashlights. :wink: (What, did you think I really NEED 230 flashlights?)

And yes, if/when I get a D18 I will mod it. I find I don’t really prefer the SST-20 so probably moments after I receive the D18 it will get new emitters… at the very least. :smiley:

I may even machine a spacer to fit the top end and make it a quad 3V 50.2, under a multi-reflector. This should maintain lumens output and actually keep it sustainable. We'll see...

FET or boost driver. Whatever Hank produces is just executed brilliantly, and it comes down to personal preference. :sunglasses:

If your asking if it has a built in circuit to prevent the batteries from being overly discharged then yes, it has this. It’s also called LVP or Low Voltage Protection.

Yes, thanks. LVP has the same meaing, yes.

@DB Custom,

Thanks for your response. I can totally relate to some of the points you brought up and like you said, totally up to personal preference. I never considered how low battery level and pulling full power can be bad for batteries. Glad I learned something new.

There will be those that will argue it’s not harmful to the cells, although I disagree. To each his/her own, I paid for all mine so I get to say how they are cared for or abused. :wink:

Let it be said that with 230+ lights on hand, and cells in every one with a good collection of reserve cells on standby… I have over 300 cells of various sizes and branding. Seriously. And I have only recently started having cells die off on me, old cells that have been used pretty harshly. I’m taking the safe route, usually. . . . :wink:

~342g without the batteries.

I was kind of hoping we could get TK to weigh it at the grocery store: