Yes, it’s availalbe, as soon as it’s 3535 footprint quad, it will be compatible .
Thanks!
I have a D4Sv2 with W2’s. Just so I’m sure I understand correctly, the difference of the boost driver would be installed is that the driver would run cooler and give longer battery life. But the lights would not be brighter or run any cooler or hotter. Is this correct? If this is so, would a cooler running driver affect overall internal temps enough to give a noticeable difference to turbo run times?
@Mobiuscorpus, the light would run cooler when it’s under regulation actually.
A good boost/buck driver is more efficient than a linear driver, and will therefore dump less heat into the light.
Thanks. I’m just trying to figure out how much cooler. I love my D4Sv2 with W2’s, so I’m debating on whether it’s worth it to buy a new one with the boost driver. I also want a different color, and would probably sell the one I bought when my preferred color wasn’t available, so I’d be getting two upgrades in my mind.
Sorry if this has been answered before, but does anyone know what the minimum brightness is with the boost driver driving a 4S configuration?
Mobius, the boost driver has no FET drive channel so Turbo output will be lower with the boost driver, especially with W2’s that really like to pull a lot of current.
Will the lack of FET hold back XPL-HI and LH351D emitters too? I would guess yes for XPL-HI but not sure on the Samsungs.
Yes. Assuming this driver has the same 2A drive current as Hank’s other 12V drivers, it’s 2A per LED which is substantially less than the ~4A normally pulled by most emitter options under FET drive with a full battery. It should produce somewhere around 2/3 as many lumens on Turbo, depending on the LED.
Oh man. I’m glad you posted this before I ordered. I would have been pretty disappointed if I got a new one and it wasn’t nearly as bright. Thanks for your expertise, Griz.
@Mobiuscorpus, actually hold on.
The boost driver has one massive advantage: no matter your battery voltage, it will try and keep output at the highest level possible.
A FET driver will never be able to do that.
Thanks for the info. I’m carefully considering my options at this point. One big question I will try to figure out is will the boost driver’s highest level be similar to the linear driver’s max regulated (non FET turbo) level? I don’t know how many amps the emitters are pulling at max regulated output on the linear driver. I know Hank just said that the new boost driver provides 2A per emitter.
So is this boost driver for the D4Sv2 the same as the one in the Tint Ramping model? I’m curious if it might be available with a backlit button.
That’s a good thing to point out too but I think many people value the pocket-rocket nature of Hank’s lights. Still, I may get one with a boost driver. Still considering.
@Mobiuscorpus, the regulated driver current on the KR4 boost is quite a bit higher than the linear driver.
You’re comparing 8A vs 5A, which means regulated drive current will be a lot higher 
It will be similar to the linear driver’s max level if the W2 is using the linear 7A or such currents.
Also contrary to what you will be told a boost driver also needs a cell capable of high current to have enough voltage headroom to actually regulate at the highest it could.
It is a different driver entirely but I would be surprised if a backlit switch were not available. It’s basically the same driver as DM11 with XHP35-HI, and that has a backlit switch.
Hi Hank, wanted to pull the trigger for a KR4 with this boost driver but Cyan unavailable.
When will the KR4 Cyan be available?
I’m curious as to why this uses a 4S (12V) design. 2S2P (6V) is more common for single-cell boost drivers and usually seems to have efficiency advantages.
Just guessing, but maybe easier/more useful to design a 4s mcpcb and 90-95% is “good enough”.
Anyone know if the 12V/4 =3V per emitter is a hard limit for the forward voltage? Would it be able to push each emitter above 3V?
3v per emitter is not pushing any of the emitters Habk listed too high, as they all should have Vf over 3v. This info is available on the data sheet , and I havent checked them all, but none of them are under 3volts.