Well, the SBT pulls a lot of amps so the 15 minutes will probably be a good estimate
See HKJ’s test HERE
/Samsung%20INR21700-40T%204000mAh%20(Cyan)-CapacityTime.png){kind=link}
Interesting. That seems kind of impractical for my use. What might the runtimes of the XHP35 HI and Osram W1 and W2 be for comparison?
As I stated above I am estimating that based on my NI40 with the same LED[SBT90.2]. However, the Aspire or Golisi 26650 has 300mAh or so more capacity than 40T or P42A[Molicel].
With the NI40 it was 10 to 12 good minutes of Combined max run time. It may not be 15 min. of combined Max output w/ 40T/P42A. Probably a little less. Remember. The light will get hot and this is Total max minutes invariably in increments of 3 to 5 minutes because of that heat.
The First thing I do with every new light is test the total amount of time[incremental] that it can sustain max, or at least when on max setting because it is dimming slightly, minute by minute. That way I know my battery and flashlight limits and my cells rarely get below 3.60v and never below 3.5V. :+1:
We will find out when we get the light.
The XHP is a 12V LED so it needs at least 25W input, that makes it about 6A minimum from one cell (losses not calculated)
See HKJ s chart for runtimes with a 40T, my guess it will pull around 8A
Emisar D4V2 and D4SV2 auxillary LED current draw here is the drain with the aux lights. I’m assuming that the aux led ciruits are the same in KR4 as D4V2 and only the main led driver parts are changed. You can see that the aux on high uses a lot of power. Will drain a battery in approx a month or so. High aux also uses more power and creates less light vs the main LED in the lowest mode. But then KR4 lowest starts at 3/150 while D4v2 starts at 1/150 so that’s debatable.
My guess would be somewhere around 8-9 amps for the XHP35. White 2 should be about 7 amps. The power it’s pulling shouldn’t be much different than the XHP35 with a full cell as efficiency is lower for the W2 driver when the battery voltage is high.
W2 should be 37mins with a 5000mah cell. XHP35 should be similar but it’ll probably not allow turbo once the battery has dropped to a certain amount.
Hank changes the thread title for every new product or info release. There have been several people asking about what cell to use for the Osram and XHP35 versions in the last couple days on Reddit.
I think your 8A guess is good, maybe even up to 9A.
It is much higher voltage at 2A forward current than 12V, more like 14V-14.4V @ 2A forward current (based on various XHP35 test you can see). This means a whopping 28W to 29W otuput (depending on LED vf at 2A) and input will be around 32W+, if the driver attempts to do constant current under such low voltage conditions the input current will get higher as the battery voltage drops and as the voltage burden affects the circuit.
This is not Reddit. Lol. 
My K1 SBT90.2 shipped ahead of schedule!
Just got my Shipping notice for my K1 SBT90.2 
Actually I got it 25 minutes ago and just thought to post it! lol!
Mine too! Thanx Hank!
This thread is still not exclusively about the SBT90.2 version of the K1. People are still going to be buying other version. Dunno what the problem with giving info on what cells the different versions of the K1 should use was. 
Oh goodie, I shouldn’t be too far behind you folks. :partying_face: I also took the opportunity to order a clip for my D4V2, which I’ve been wishing I’d gotten with the light.
Yes, the driver pulls more amps from the battery as voltage drops. This keeps the output flat, but it also has the side effect of triggering a LVP step-down a bit sooner than what would happen with a linear driver. And then afterward, the post-drop output stays flat for a longer time because the battery’s voltage rebound effect is larger.
Basically, the LVP step-down process takes longer when using a boost driver, because each step starts slightly sooner and lasts longer. The same effect seems to happen on other boost drivers too, from other brands. When I measured runtime on a K1 with XHP35, the graph looked pretty much the same as a Zebralight with the same type of LED. At first I thought it was strange, but after comparing to other lights I found it reassuring that the K1 behaves the same way as premium brands.
I hope things shipping to Canada returns to normal soon…. everything seems to end up trapped in Singapore…… for me at least.
I want to buy a KR4 so I was asking myself… Can we program that led with Anduril ? (I’m gonna program my own and I want to be sure I can disable the tailcap led if finally I don’t like it to be powered permanently.)
Does it consume a lot?
The light in the tailcap is a trit.
You cannot turn it off, you can only remove it.
Look up tritium.
Sorry, for a french the term wasn’t so obvious and seeing the pictures I thought it was a led. XD
Thank you for your answer, I can purchase in serenity, as it’s no something that consume batteries.
You can also order without it if that’s not your thing.