Emisar D4K dual channel 21700. The unicorn?


Jun 27, 2021
Never being one to shy away from a new idea I took a leap & ordered a D4k dual channel light.

Dual Channel D4K 21700 EDC High Power Led Flashlight Flashlight host color Cyan Switch retaining ring type Raised version Switch Backlight Amber Channel 1 Neutral White - SST20 5000K Channel 2 Neutral White - SST20 4000K 95CRI Please Choose Additional floody optic, SS bezel , deep carry pocket clip, Magnet in the tailcap

I've learned a few things. First & most important ; you need to be comfortable programing the light (Anduril 2). If you aren't this is not a light for you. Second ; I didn't pick a wide enough spread in performance in the LEDs to get the best use of dual channels. Third ; the lumen output from these LEDs are to high to be use at the same time, ie: on turbo. Even with the temp calibrated using both channels on turbo the light was HOT to the touch in less than 10sec & stepping down at almost the same point.

I turned turbo off to dual channel use & limited each channel to 120 out of 150 in output. Part of the reason was battery life, even using a HQ 21700 40amp 4000mah battery I was able to drain the battery twice before I got everything set to my liking. I'd judge the 120 level to be near 2000L which is fine for my needs.

The build & detail on the light is first class all the way. Size for this 21700 light is even smaller than a Sofirn IF25a & that light is smaller than most 18650 lights. This is a true EDC size from a 21700 format. Beam is slightly oval at shorter distances (15'& under) given the each channel only runs two LEDs. I didn't used the floody optic with the LEDs I have in this light. The magnetic tailcap is plenty strong to hold the light in place even at 90d to level & the pocket is easy to use & holds well.

So the platform is awesome (as long as you are OK programing the UI) & I have learned from my error(s) & ordered a 2nd light with lower total lumens on each channel & a wider gap in throw vs flood in LED performance.

This is really looking like an EDC light with throw or flood or BOTH (if I can leave turbo on using both channels) with truly usable run times & a 90 CRI (or better depending on LEDs)

Grades? Light platform .. Solid A ; the way I spec'd my first try .. C ; battery life (w/these specs & 4000mah/40a battery) B-. I'm hoping a 5000mah/20a battery will be good for the 2nd light

I doubt I'll get rid of this first try as it does work well, you can see the difference in throw/flood/CRI between the channels just not as much as I'd hoped


Dec 16, 2003
Consider running it with an LFP cell. It will run much cooler on turbo because the driver isn't bucking the excess voltage and the brightness seems unaffected to my eyes. The only penalty is runtime on lower levels due to the lower cell capacity.

Also keep in mind (if you order another one) that one of the channels has FET drive on turbo and the other does not. I think channel 1 has it. Something to consider when selecting emitters

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