ONLINE! Haikelite HK4S groupbuy - Quad SST20/40 26650/21700 flashlight

Reduce the height on the brass + contact or it will dent the top of your 26800 cell. The top post on my 26800 got pressed in a few mm’s, just cosmetic.

K, thanks! Will do.

Does this have regulated driver?

No, unfortunately. Just instead of using the old classic 7135 0.35 amp regulator for low modes, it uses a circuit that I think emulates a 7135. Anything above 0.35 amps is PWM'ing a full open FET.

Would you mind to share the compiled .hex?

I've upgraded the Anduril 2 version since, not yet downloaded to my HK4S. I should do that first, make sure it works, then post it to my google drive share. Hope this weekend I can get to it.

I would love to get more into tinkering with anduril (coding-wise). Which cfg did you use to get started for the HK4S?

edit: I think I’m slowly getting the hang of it :smiley: Used the Emisar D4 and added the button-LED. Thanks

Appreciate posting this test results.

I also got the HK4S (4x SST40), and noted it has somewhat low brightness (I don’t have a light integrating device, but I record ceiling bounce lux measurements — I understand this is not accurate, but usually can get a ‘ballpark’ lumens based on comparing my other ceiling bounce lux measurements of similar beam type flashlight), at first my lux measurement would indicate a “guesstimate” lumens of only around 4000 or less lumens on Turbo (this is quite far from the manufacturer “7000” lumens), tailcap current measured was just around 14 Amps. (I didn’t notice ‘flickering’ on Turbo mode though, which may indicate poor contact but…)

I then checked the retaining ring on the head portion of my HK4S — and it appears it is not that tight, so I tightened the retaining ring a bit more. After doing this, I checked tailcap current, and it imporoved — it’s now at around 18+ Amps on Turbo mode, and my ‘guesstimate’ lumens (via ceiling bounce) would be in the ballpark of 5000 lumens or so. (I used a “somewhat-used, but nearly full charged” Samsung 40T and used the longer tailspring option when I did the ceiling bounce lux (guesstimate lumens) measurement.)

Reading that you get 22 Amps tail current (with the improved wires), my guess is that the default installed wire would be limiting the current being used by the HK4S (unfortunately, I’m not skilled in modding/soldering so if it’s not broken, I generally don’t touch it because I may worsen it further…)…

Sorry, been bizy. I started charging the QB26800 in the light but it was going at 0.5 amps starting at about 3.55V, rather slow, so I rigged up some wiring in one of my SkyRC MC3000's, yes - I got two, best charger out there. I soldered up 2 magnets on 18 AWG, kapton taped up a 20350 battery, and added some cut copper sheet to the end of the 18 AWG wires so I could sandwich in the wires at the ends of the 20350 cell. It worked charging at 2.8 amps, but was seeing some strange behavior. The QB26800 acts like a weak or old cell in the MC3000. Not sure if it's the cell or the way I had it wired in the charger. Haven't tried it yet - should do so tonight.

Too much work. Olight magnetic charger charges at 0.75 amps. Bought 3 chargers with 5 batteries and usually just play top off.

Replaced the brass batt+ contact, as recommended:

Original on left, new one sanded down to ~1.7 mm:

It's an excellent fit now.

Really was kind of simple, but I think I got too much resistance somewhere. With the MC3000 set to 4.22V, it only hits 4.20V then drops to 4.19V when removed.

On the triple SST-40 5000K HK4S on the QB26800 at 4.19V (w/20 AWG spring bypass):

  • 20.1 amps (clamp meter at tail)
  • 4560 lumens at start, 4410 at 30 secs
  • 46.8 kcd taken at 5 meters

Measured earlier on a 40T at 4.21V (w/20 AWG spring bypass):

  • 22.3 amps (clamp meter at tail)
  • 5480 lumens at start, 4590 at 30 secs
  • 51 kcd taken at 5 meters

As you can see, the 40T has a huge drop, mostly in the first 15 secs. The big cell has lower readings but much more steadier over the first 30 secs. Pretty much as expected.

Hey Tom, I have had my eye on this light since it dropped. I nOw have had the ft02s xhp50 and EC03 sst40z

How is this light? How is the beam with the SST 40? I see it as one of the smallest head sizes available with 4X sst40. I am thinking of running it with 40 T battery and spring bypass with that longer spring, do you think this is a good option? I’d rather bypass the spring then replace a button on the head and run with a larger battery. Also I have 100 pack of heavy duty O-rings I could use as a spacer to fill most of the gap in the battery tube for the diameter difference. Thanks for the amps and lumen count!

Hhmm, I like it but I can't offer much info on it right now. I'd have to do some careful looking and comparisons. Hhmm, think'n the short spring bypasses might be better, otherwise you have to sand/grind down or swap that brass button like I did.

The big QB26800's are back in stock: https://alofthobbies.com/qb-26800-6800mah-37v.html

Decent deal shipped for qty 1 or 2.

Has anyone checked for parasitic drain?

Hhmm, maybe not. Might be in my notes, or can check it this evening.

Standby drain is a bit more complicated these days. 2 important factors are the battery (drain is higher on a better battery), and with or without the switch LED. Anduril and Anduril 2 support 2 levels of the switch LED, but you can't control the low level independent of the high level. So I took some #'s on the HK4S:

  • stock HK4S (from FastTech, SST-40 5000K): switch LED Off: 111 uA, low: 151 uA, hi: 1229 uA
  • slightly modded HK4S (from BG SST-40 5000K): switch LED Off: 126 uA, low: 164 uA, hi: 2240 uA

All taken on a QB 26800 @4.18V, same cell used for all tests

Modded HK4S is running Anduril 2, 18 AWG LED wires, MX-4 grease, sanded shelf and back of MCPCB. Just looked at my notes in post #37 and noticed they have the voltage divider R1/R2 populated, and Anduril 2 doesn't use it. It adds to the drain. Without voltage dividers, this driver/firmware combo should be 20-40 uA with no switch LED.

The draw of the switch LED's on hi is big. Think the blue is not the best, green and orange always do better, and the cap translucence isn't so good but the switch LED is still pretty bright on hi. with Anduril, I like setting the switch LED OFF when the light is locked out to reduce the drain.

Thanks, Tom, very complete answer that I appreciate since I am getting back into flashlights after a long time. Reminded my of the motto from my college - knowledge and thoroughness.

Need to update my photo, it has been so long I have 3 different middle aged dogs!

I was out somewhere with little signal so I didn’t read the whole thread, but I have now… Looks like I should do all these mods and I do like the idea of 26800. Maybe I will see if there is a combination that lets me use 26650 and 26800. I seem to have gravitated toward 26650 except my headlamp/edc.

I don’t mind the drain if I can unscrew tail enough without it being wobbly.

Just ordered mine, as you saw, maybe the white led is gone by now. So weird. Probably wishful thinking.

I am guessing my equipment is too inaccurate but I will check mine out as I mod.

Good to see you back! Think I saw other recent posts. Love the dogs! We got a 4 year old black lab, got her from the Guide Dog Foundation, taken out of the program because of a health risk issue, so she's got a great calm nature, loves people and animals. Took this on Sunday:

I told her to come, and sit - she was fine with that but kept an eye on the birdie :

Brave little northern mockingbird? My uncle had labs. Nice dogs, but none as gentle as yours! 2 mutt rescues and my first non rescue of the 13 dogs I have owned, ready to head out for the weekend.