it depends which driver you currently have from Hank. He has linear 9amp cc drivers that would provide more regulated output than the boost driver at 8amps. But like others have said, the way the boost driver functions (converting battery voltage up to 12volrs) it is inherently more efficient than a linear constant current driver (CC).
Also, what someone said is also true, you will need to run batteries that are of a high enough quality and CDR (continuous discharge rate) that can handle that conversion of the boost driver. Sony vtc6, molicel p28a or P26a and others are some that would perform well.
But another thing that hasn't been spoken about - the high output of a W2 with FET driven turbo (something not on the new boost driver) is only as good as it's thermal capabilities. And I know this is an age old debate, but theoretically the boost driver creates less heat (it doesn't convert "leftover" battery amperage into heat like a CC driver), has more efficiency, snd Bc of its slightly less output it will definitely have more sustainable brightness. So it comes down to a question of something like: would we rather have 4000 lumen turbo for 25 seconds that goes down to 1000 lumens over 1-2 minutes? Or would we rather have 2500 lumen turbo that holds for 1-2 minutes and ramps down to 1500 lumens for a longer extension of time.
those are theoretical numbers, but the point is the same. More brightness for longer. Some people want the most brightness regardless how short it is (your current setup with CC driver + FET turbo), some people want as high output as possible for as long as possible (this is what the boost driver will deliver).
I myself try to have a mix of these lights, Because IME different situations call for different needs :)
Iām coming to the conclusion that I would probably prefer the type of output offered by the boost driver. Iām sorting out all the details, but I may very well end up ordering a new light with one. Since many people seem to have missed this in my posts, Iāll point it out: I donāt have, nor am I interested in, a D4V2. I have a D4Sv2 with W2s and a 26800 tube. I donāt know how many amps that driver pushes. Iāve emailed Hank, but if anyone else knows for sure, Iād appreciate knowing. Also, since the gold QB26800 cells put out 20A continuous, Iām thinking my battery should do ok.
In many flashlights the battery tube screws on, this is never going to be the optimal way to transfer heat. Between small air gaps and the different style threads cut into the tubes it can be a poor way to transfer heat away from the head. Not to mention surface imperfections of mating surfaces.
I think itās been fairly discussed that the better thermals of a unibody might allow the surface area of the flashlight to be more efficient in radiating heat out. Instead of keeping that heat in the head more of it would be effectively transferred to the tube allowing things like the extra surface area of the anodizing to help emit heat. I think of like a copper head on a titanium light like the D4v2. That copper head is going to be really hot and that titanium body tube not so much. Much of that is the thermal conductivity and emissivity of the metals, but I believe poor thermal transfer can behave in a similar way.
Zebralights arenāt just about having a boost driver, but their PID temp regulation is absolutely the best out there, and the lower modes have unmatched efficiency. They are also built to be non serviceable which allows them to be more compact. SC700D remains my favorite flashlight despite its ugly green tint.
I have the SC700Fd and although diffused it really isnāt that green certainly no worse than some of the best LH351D I have seen. I am really glad I listened to a fellow redditor and got the diffused glass version, nowhere near as throwy but I love it, and of course very good efficiency. I see why they are so highly regarded.
I love my zebralight, but I'd trade 4-5mm in length to have the benefit of changing my own driver if I ever needed to. But that may be a little over the top on my end.
I wasn't referring to a D4v2, and didn't see anyone else either. The D4v2 isn't going to have the boost driver for awhile which is why I wouldn't think anyone mentioned it. Also, the D4sv2 isn't going to have the boost driver again either. I asked hank. He said no. The limited run was it. Unless I misunderstood him
You would need to get a kr4 To get the boost driver. Unless I missed a post stating otherwise.
The D4 is not much bigger than the SC64 on paper, but in a pocket it feels quite a bit bigger. The SC64 has metal removed wherever possible to make it thinner in most places than its published outer dimensions, and lighter. The screwed-on pocket clip and recessed button are significant ergonomic advantages as well. I donāt care so much about it being a unibody design, but that also helps it be smaller. That kind of machining adds to the price, but the benefit is real.
Itās also the emitters. A small reflector with a single emitter is not a recipe for pushing the limits of output and throw, which is where Hankās products have typically broke new ground. It is, however the most popular design for EDC lights for good reason. Thatās a very practical beam profile.
Thereās probably an increased market opportunity at the moment. Zebralight has run out of XHP35 HIs and doesnāt appear likely to replenish that supply any time soon. Furthermore, the B35A and 519A are both glorious and well-suited to a light like that.
The reason I assumed you thought I had a D4V2 was that you specifically mentioned several high drain 18650 cells. No worries though. I got the message. As for the availability of the boost driver in the D4Sv2, about ten or fifteen posts above you, Hank announced it had been added again, and is now a current option on the ordering page.
ohh, ok. I understand now. Yea, I mentioned the 18650's Bc I thought the only options were the KR1 and kr4. That is my fault. I should've read more (further) back before chiming in. I often get excited to share the little info I have and then ramble on too Much anyway.
thanks for the heads up on the d4sv2 info, that's cool!
Glad to help. Since weāre discussing those 18650s, I have a question: I actually ordered a KR1 with boost driver and B35AM a few days ago. I had ordered some Sanyo NCR18650GA cells, which are 10A continuous. Will those be enough for a single B35AM on a boost driver? Or should I shop for a higher current cell? If you think I need higher current, what is the bare minimum I should consider for best performance?
