The D4v2 E21A driver isn’t actually a KR4 driver. It’s just … electrically compatible. Same logical design, but different physical design. An actual KR4 driver would not fit into a D4.
Which firmware build does the D4V2 E21A use? I wouldn’t want to flash the wrong version if I decide to make any changes.
Thanks.
Edit: I just remembered the map file you added. Looks like it uses the kr4-nofet firmware.
Will that FW work for the Ti version, too, with the lighted switch?
Yes, I merged lighted switch support into the KR4 firmware, so it can be used on the D4v2 Ti with E21A.
Originally I had a separate “D4v2.5” firmware for it, but the only difference from KR4 was the lighted button… so I merged them together. I don’t think I ever published new .hex files for it though, so the most recent ones on my site are still d4v2.5.
Just make sure to use the noFET version. The FET can destroy the E21A LEDs very quickly, so it should not be enabled.
Thank you. 
That’s good to know, thanks. Hank said the driver has a diameter of 22 mm, and I gather it essentially runs the KR4 firmware. I’m guessing that means regulation is equal, there is a FET present (but probably disabled by default), and it can be reprogrammed using Hank’s kit?
That would be the most relevant things for me, hardware-wise.
if the E21 builds heat slower than the XPL HI, what are the lumen differences?
XPL HI and SST 20 seem like a wash lumen wise… but if the E21 builds less heat……………
XP-L HI can make about 4000 to 4500 lumens at about 15 to 20 Amps. E21A stops at 5 Amps and maukka measured it at about 1200 lm.
The main appeal of E21A is that it’s high-CRI with a nice tint and a variety of good color temperatures. The clear optic isn’t optimized for E21A though, so it uses a floodier frosted optic instead. It’s a close-range flooder for high-quality illumination.
XP-L HI is more throwy and makes a lot more lumens.
Thanks TK
Again
My choice has been made
I would like to petition Hank to use retaining rings instead of glue to secure the drivers. I do not know about the other lights, as I only own 4 variants of the D4V2 Ti and a KR4 Ti, but I am sure mine do non have retaining rings.
That would enable enthusiasts to replace any faulty drivers and upgrade to new driver versions.
I hope enough of us want this to convince Hank.
I agree completely.
Don’t own a sst-20 . The top of the ramp is similar with a slight advantage for the the xpl-hi ; but of course you have the turbo for the xpl-hi witch is almost inexistant for the e21a .
For flashlights like D4V2 with E21A, which does not use FET turbo, I like to set the top of the ramp to be the same as turbo.
The Cracked and Splash look amazing, remind me of Trapper Keeper designs around late 80s / early 90s. That’s a full compliment, they are bad @$$. Hope they are available around Christmas.
Yeah, it was between grey cammo, cracked or splash for me. I finally bit the bullet on splash with a violet trit and xpl-hi 5000k.
I can barely wait!
Very tempted by the K4 E21A. Will cooler CCTs be available?
(Now, if only Convoy could make a quad E21A S2+)
Trapper Keeper! Thats it! Wow I haven’t thought of those in 20+ years lol. These new KR4’s are AMAZING. you have a sick light coming your way!
The KRs look great, but I'm quite partial to the excellent side switch.
Are there any compact throwers, with side switch, coming up? Something like a D1/K1, but with a head the size of the KR1?
Lost my beloved D4 EDC (with 219C) recently and will replace it with a new D4v2, but I would like to get a thrower as well!
Maybe a D4v2 with SST-20s and 10621 optics would do the job? Or is that still mainly a flood light but with more throw than from Nichias?
The D4 with any currently existing LEDs won’t come anywhere close to the beam profile of a dedicated thrower, or even a compact one like a D1/KR1.
A question of my own, does anyone know if the tailcap retaining rings in recent KR4s is glued or has locktite? I wanted to remove mine to try it without the metal switch cover but cant seem to get the ring to budge. I do vaguely remember Hank saying something about the first batches of KR4 having some easily remedied connection issue that is now fixed in production though too.
I just received KR4 with E21A/5000K in black. It is a very nice light. I like it very much.
There are some questions about the AUX LED’s. This is not my first light with Anduril with AUX LED’s, so I think I am navigating through the functions OK.
Everything works fine with the high mode. All the colors are nicely defined and beautiful.
The low mode is a different story. (I mean high/low mode = the brightness.)
When any mixed color with green is on, only the green is visible. So, the colors are supposed to be sequenced from red, yellow, green, cyan, blue, violet, while, rainbow, and volts when 7H. However, with the low mode, it goes from red, green, green, green, blue violet, green, partial rainbow, and partial volts. (partial = any mixed color with green = green).
So, when the AUX LED’s are on blinking, the colors are good through the high phase but not good with the same issues through the low phase (green only for the mix).
I am using the freshly charged battery.
Do you think there is something wrong with my new KR4? By the way, the light from the main LED’s are very nice.
Thanks for the help.
It’s simply that at very low power levels those emitters have widely varying brightness depending on color. The several Emisar/Noctigon with aux lights I’ve had all had the same behavior - red is much dimmer than green and blue on the “low” setting.