Eh, I prefer the good old take the battery out and swap in a freshly charged and place them in a dedicated charging bay. I don’t need extra cables and a good charging bay with a few spare batteries works better than having the light out of commission while charging. But that’s my 2 cents.
Oh I agree. I rarely use built in charging. It’s a nice addition for a non-EDC, as long as it doesn’t hurt waterproofing (like Hank’s design on K1). For a EDC I don’t want built in charging, just makes the light bigger.
Thanks TK, nice write up. And thank you Jordan ZHP for the heads-up, ordered the grey one with a 1x1 White Flat for ultimate throw. Didn’t realize just How MUCH Bigger it is than the D1S until I located this thread though. Love it! 
Can’t wait to see it in hand.
First light I’ve purchased in a while, may or may not use the C charging but at least it’s there in a pinch.
It sounds like you’re getting the best one. If you’re getting a thrower, may as well make it throw. 
I didn’t think I’d use the built-in charger, but I’ve found it really useful so far. It can charge at 2A, and my only other 21700 charger maxes out at 1A. So it has been pretty handy for reducing the time between runtime tests.
Once that’s all done though, I might stick with the external charger for the simple reason that my driver isn’t glued and I don’t want to risk breaking any cables or connections by unscrewing the handle a lot. But this wouldn’t be an issue with a production unit.
Anyway, it’s nice having something with a beam similar to a GT but small enough to actually use.
Someone convince Hank to make a tail switch accessory and I might have to buy one of these - I know Anduril already supports dual switch layouts, and the flashing pads will make firmware modifications a breeze.
Thanks for the review Toykeeper.
It is noticeably bigger than the D1S, but performance is top of its class and makes lights like the BLF GT a little obsolete.
Looking forward to see the specs of the Boost driver version with XHP35.
I’m really eager to see the specs of the boost driver performance. I think driver efficiency is a neglected attribute in the enthusiast market lately, especially in small lights where heat matters (not that the K1 is small or prone to overheating). It may end up being hard to pick between SST-20 and XHP35 HI.
FWIW, runtime tests are still in progress. I’ve added some results to the graph, but I’m still adding more as the tests finish.
It may be necessary to shift-reload to get the newest version of the image though. Browsers might cache it even though the timestamp has changed.
Results are pretty much as expected — nearly flat until the battery voltage falls below the LED voltage, and then it slopes down in a shape directly matching the battery’s discharge curve until LVP activates, and then it stair-steps down for a rather long time until finally shutting itself off at 2.9V.
Even on a low battery though, just before LVP activates, it still makes 100+ kcd. So it out-performs a D1S or GT-Mini until the battery is at like 3% charge.
Nice! Thank you for the runtime tests. I just grabbed 4 more Samsung 50E batteries while they were on sale for $5 a pop. Might have to splurge and get this awesome light. Still having trouble deciding between the 2mm and 1mm. This is an awesome light.
Can we start a thread where we accidentally get drunk and buy things, recently by Hank, and mostly by Hank. I’ll update tomorrow when Elysia knows what I did. What’s wrong with us? Thanks FTK…
Might be interesting to fit the 90.2 to this beauty…
…plus strobe mode.For self defense of course…
I did the same thing. Had just ordered myself a replacement D4V2 and the K1 wasn’t on the site yet. Sitting down with some beers and popped my head into BLF and theres the K1. Went straight back to Hanks site and there it was. Immediately ordered it in Dark Grey W1……
Me and a few others have suggested that. He said the driver is only 5 amps but the WF2 version is pulling around 8 amps. All he has to do is add a direct drive turbo mode.
I could not resist it anymore and ordered a K1 W1
I don’t have any experience with white flats. Do they have issues with green tints?
Not at all
It hasn’t been measured that I’m aware of.
However, it doesn’t look green to me, and I usually notice even mild green tints.
On the other hand, “white” gets a little weird at 6000K. Some standards actually shift the ideal tint line up at CCTs above 4500K in order to match perception better, so a positive duv at 6000K means something different than a positive duv at 4000K.
Here’s a recent chart from maukka, showing the alternate standard for white:
I’m guessing the White Flat is probably on the dotted line around 6000K, but that’s just a guess. I think it’s designed for use in video projectors, and its color distribution is pretty close to a computer monitor.
Yep, had to order one. Got the W1 for ultimate throw. Will be my first mega thrower.
As TK also noted, tint measurements of the White Flat may not have been posted yet, or I may have missed a maukka test. Here is a quick measurement of the hotspot from a 1mm2 White Flat in a shorty Convoy S8 with smooth reflector, uncoated lens, at three non-exact-defined :innocent: currents.
Low-ish current:
CCT=6500K, duv= –0.0012, CRI=68
High current:
CCT=7370K, duv= –0.0075, CRI=69
Highest current (I assume around 4.5A):
CCT=8488K, duv= –0.0113, CRI=72
So no green, duv is always negative, at highest current tint goes towards purple.