Oh wow, such hype! Thatās another must purchase.
It looks so nice and fat too.
Maybe there will be a 26350 option too?
I also wonder if the extra length is for some of the jumbo-sized 26650 cells out there or maybe with a sleeve to accommodate a 21700. Looks cool anyway.
Oh Lord! Where does it end? Yet another MUST HAVE light! :person_facepalming:
I expect the lanyard hole adds a few mm in length as well, glad to see that included!
Has anyone before in these 4700 posts actually checked this?
And where in the driver is this power (24W!) burnt off? 
(the light is fine after 10 seconds reverse battery contact).
That dark blue D4s looks awesome, but is that a new blue DRESS next to it as well? It looks shinier than the old Cyan color.
Oh wow 26650 D4!
Good catch.
Comparing manufacturer predicted beam specs for XP-G emitters, since both manufacturers have that emitter modeled:
Carclo 10622: 4.3 Cd/lm
Ledil C12885: 8.0 Cd/lm
Aside from a different optic, I wonder if the additional height also fits in any changes to the driver.
Given more PCB area, it seems pretty reasonable that additional 7135ās could be added, although that doesnāt add height.
To be honest, Iām not thrilled with the optics choice.
Not that Angie is bad, quite the opposite, but siamese optics are a proven choice that enables higher throw in the given size.
Angie with a rotated-pad-pcb is going to deliver a largely artefact-free beam. But personally Iād rather take a large few minor artefacts for a more pointy beam.
Still hoping they will come out with an aluminum 18650 battery tube for the D4 with knurling.
I hate smooth tubes and the Titanium version is too heavy for my pocket.
Holy crap, I want one.
Gonna start browsing for 26650ās in my vicinity.
Iāve got plenty of batteries just waiting for something like this. This is exciting. When can I get one? What are my color choices?
I guess that Iām the only one that is concerned about a 6A current and 24W of heat produced in the head when the battery is reversed. Say I put in a 30Q in a D4 the wrong way, close up the tail and do not check if it works and put it away. The sustainable power for this size light is about 8W so it gets hot fast. Perhaps some part on the driver will go at some point, will it break the circuitry or will it create a dead short?
I think that it would be a good idea for Hank to address this problem.
This is already known. I didnāt know it was ājustā 6A instead of short circuit. Yeah, the light protects itself, but a dangerous situation is created if you leave the light like that. I think Hank already knows as wellā¦
You are not the only one. It was already concluded by someone here that the reverse polarity protection was a flaw, was it toykeeper??
You probably should stop doing this 
Youāre not the only one. I just donāt have a resolution except to consider this one of the reasons casual users should not buy this light.
Iām actually a bit surprised 6A for 10 seconds didnāt kill the light. The driver PCB is fiberglass, right? So itās not going to take much heat away from whatever component is soaking it up, nor get that heat to the head very quickly so a user can feel the warming, indicating that something is wrong.
An early post of TK answering (before it was know that it didnāt have protection)
Since then, it was discussed some time ago, from here onwards:
Also, TKās post after that:
Glad I never managed to put the battery in reverse position :person_facepalming:
Weāve pretty much all known since we were toddlers not to stick screwdrivers in wall outlets. We survive those little holes in the wall, perhaps we can put a battery in a flashlight the right wayā¦
Yeah, Neal posted that on facebook.
I donāt think he was supposed to reveal it yetā¦ I think Hank wanted to be the one to announce his new product. But Neal can only keep a secret for about 5 seconds. 
Iām hoping to do a review soon, if a D4S shows up in the mail. Iām going on a trip soon though, so Iām not sure if there will be time before I go.
I gave Hank some emitter suggestions, but I donāt know if heāll do what I suggested.
Specifically, I told him he could avoid the heat issues of the 90CRI 219c by using 90CRI LH351D instead. And I told him people would really like a 4500K version using two 4000K and two 5000K emitters.
I hope heāll make that happen, but I have no confirmation about it either way.
The reverse polarity behavior was noticed fairly early on, and I notified Hank, but I donāt think he ever fixed it. It doesnāt seem damage the driver, but it can damage the battery.
It appears to be fixed in the D4S. I checked a moment ago, and my DMM measured zero on a prototype with the battery inserted backward. The same DMM measures about 4A to 6A on a D4 with the battery in backward.
First, I just want to note that iamlucky13 currently has exactly 13 posts. 
About the driver though, it does have some changes compared to the D4/D1/D1S. I donāt have a production model yet though, so Iām not sure what all the changes are.
It seems one change is fixing the reverse polarity protection.