That doesn’t sound right. E21A (except possibly mules) should be limited to 5A current, XP-L HI should consume more than 10A with a decent battery.
Is either one of your E21A flashlights a mule?
Did you calibrate the temperature sensor on all flashlights?
Is the temperature limit set to the same value on all flashlights?
On the max CC setting it would get hotter due to lower vF, AL pcb, no thermal pad wouldn’t it?
Yes, the D4v2 has less thermal mass than the KR4, so it heats faster.
Edit: at the same power levels
If one light is running at a higher power level than the other, like a direct-drive XP-L HI vs a regulated E21A, the higher-power one should heat faster. Because 20A of power vs 5A is a much bigger difference than anything caused by the LEDs or the small difference in host size.
I noticed Tailcap with trit slot but no trit pre-installed is missing as an option for some flashlights, like KR4 Ti.
Given that Hank is apparently happy to stuff the KR drivers into other lights, does anyone know if it’s possible to buy them separately?
I’m not sure about the kr drivers, but recently I bought a couple d4sv2 drivers from hank without any issues. Just send him an email and see if hes willing to sell them to you.
Good instinct . I did a test with 2 fresh 30q on 2 d4v2 ti . One with xpl-hi 5000k, the other with a mix of e21a’s 3500 and 5000k . Top of the ramp . Fingers on the copper . The xpl-hi gets hotter faster and seems to cut the power sooner . I did a second test holding a kr4 ti and a d4v2 ti, both with e21a’s . The kr4 is an easy winner . I’m using 30q’s from a single purchase but they seem to have different power . I will retry those test switching batteries .
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.