I should just add for completeness the reason it’s quoted as 2A not 8A is because the LEDs are in series in the boost driver. The boost driver works by increasing the voltage to say 12V and driving up to 2A through the circuit, and then relies on the LEDs being in series to create an appropriate voltage drop across the circuit (each LED gets the 2A of current flowing through it, but only a part of the total voltage drop). The 5/7.5/9A drivers have the LEDs in parallel so they share the current the driver is giving them. There are likely a lot of electrical engineering subtleties, but that’s my simplified way of understanding it.
Output should be measured in watts. But manufacturers not doing this for some reason. Only advertising mooore low cri lumens 
I haven’t seen “watts” on a flashlight since my dad and I were looking at those Brinkmans in the camping section of Walmart back in 1994. Don’t hold me to that year, I’ve slept a lot since then!
Light output shouldn’t be measured in watts, but power input and output should.
The boost driver at its highest output should be consuming about 26W and putting out about 24W (claimed efficiency is 90-95). The 5A linear driver should consume about 5A * 4V = 20W on a full battery, accounting for voltage sag. Four 519As in parallel don’t need 4V for 5A though; they need 3, so the output is 5A * 3V = 15W. That’s 75 efficient.
My kr1 gt fc40 3000k is absolutely one of my favorite lights!
also the dm1.12 I installed xpl-hi 4000k into is as well!
and some shorts including dm11 sbt90.2 !
So approximately what % increases in sustained brightness (once thermal limiting comes into play) should we be expecting with the boost driver compared to the linear/FET driver?
Relevant for monochromatic sources or applications where radiated energy is important - watts out vs watts in. Less so for determining the performance of white light which needs a good distribution across the visible range to be useful for human vision.
Standard for flashlight advertising ever since we stopped obsessing over candlepower from low-lumen incandescent filaments 20+ years ago. At least today’s “low CRI” LEDs are typically ≥70 as opposed to the ≤60 CRI of a decade-plus ago.
A KR1 style light with head diameter <28mm, and would make it more useable for light painting.
So meaning, from members knowledge. the new boost driver will have gain and lose and also how much gain/lost depending on LED option. How much gain and lost will depends on individual needs.
For the options now, the gain(significant), the lost(insignificant) will be the Nichia 219B from a 9A linear to a 8A booster….
Will we ever see an all brass KR4, or is that option in the Secret Menu?
So why new boost driver is limited on 2A per led? It is impossible to put inside flashlight bigger inductor? Or does the price and complexity of the driver increase noticeably with more power? Does it make sense to wait for a new driver for, let’s say, 2.5 or 3A per led in future?
Using charts from reddit, I calculate that in best case we will get 2400 lm from 4x 519a with 2A per led. Of course, I wish there was more.
3A12V/6A6V is about the maximum reasonable power with the MP3432 boost converter used in these drivers, but indeed it would require a larger inductor than the one currently used, pictures of the D4Sv2 driver were posted and reddit and it looks like a 6030 sized inductor (~6.5x6.5mm, 3mm tall), something like 6060 or 7070 inductor would do but the D4S is limited to ~3mm, the KR1/KR4 body has been updated for the boost driver but probably just to 3~4mm (?) and not to 6~7mm driver cavity height.
i had been thinking Lately how awesome a 14500 KR1 would be!
OR,
a 14500 version of the D1 !
Reflector please!
I personally don’t think 14500 (or 18350) have enough capacity for hotrod lights - it’s like trying to power a Ferrari with a 10litre fuel tank. I don’t go smaller than an 18650.
On top of that. How’s the focusing of the beam going to be? Even the Antman, which is a LEP struggles with focusing.
Ain’t gonna be a pretty thrower.
well that's the thing, I've been on a "lower power / sustainable / less heat/ small light" kick. So I wouldn't want this Emisar/Noctigon 14500 to be a hot rod (my opinion, i may be in the minority here)- but i would love a sustainable, superbly made 14500 single emitter light (thinking Skilhunt m150 or ZebraLight or picl one), but with all of the amazing custom options Hank offers (emitters, tints, cri, drivers, ano colors).
basically everything there is to enjoy about small lights (pocketability, light weight) but with Hanks plethora of options. THAT would be the selling point in my mind! No V10 needed :))
basically - no other company is offering all of these options in the AA / 14500 size. Hank making a single emitter light with his "normal" options would dominate that market!
Not really honestly.
I believe Emisar is at a point where there are too many choices for LED, options, secret options, etc.
If he wants his light to dominate a market, he needs to go mainstream. That’s it, that’s all.
ehh, I mean maybe I misspoke. It would dominate the enthusiast market. Not mainstream, but we aren't the mainstream flashlight crowd (if there is such a thing). We are enthusiasts. I don't think there's too many options, only for the new people. But once you get the hang of what cri and tint are, then it's not bad. I mean the new boost driver stuff throws an added element of complexity, but to the average user or a newer enthusiast, the boost driver is a territory they need to not worry about (at first).
I just mean, for folks like most of us (people on a flashlight forum), options are key. If I could get a ZebraLight sc5 or sc53w in different emitters or tints, I would probably own multiples of them. But I've never bought one and probably never will, bc I have no interest in paying $55 for a light that I can't choose the tint/cct on.
I think Hank would do well in the AA / 14500 market, not to mention it would be something unique because that's how he operates.
Hank’s lights are aimed at enthusiasts rather than mainstream muggles.