Please henceforth just tell us the lights you don’t buy. Shorter list 
I spent some time testing with a few various 16340 cells and couldn’t get mine to do what you described. I didn’t test it with a meter, but I can tell it’s pushing the battery pretty hard, and I could get it to trip the protection circuit on a couple cells and shut the light off. It does seem to step down after about a minute. Once I thought I saw what you were describing but I put it on my phone’s camera and it could see it. In fact, my camera shows that my SF3 is quiet as a mouse with respect to PWM or circuit noise.
The SF5 NW just came in from WallBuys today. It shipped a couple days earlier and arrived a day later, so hkequipement is the shipping winner here. Both are fantastic lights and I’m so glad I put off buying an SC52. The SF5 NW has a slightly warmer tint than my SF3 NW and I like it!
So far the photos are coming out nice. Here’s a teaser shot:
I tried again draining the battery but this time only on high. The protection tripped after 55 minutes without any flicker or noticeable step-down. Comparing to this graph taken from a review, the result seems spot on. I may need to try again to see if there any in turbo mode.
Do you have an idea on the current which the led is driven at?
I’d like to replace it with some Luxeon I have.
Mine arrived today. I ordered it on the 8th, so that was fast.
I’d like to thank JMPaul and HKE for doing this. I arrived in this thread after the GB was already going and they graciously allowed me to get in on it.
I ended up getting the SG5 headlamp, but given the build quality, I only wish I’d give into temptation and gotten the flashlight as well. I’ll post up a picture some time this weekend.
Thanks again, guys.
I got my SG5 today and I can say that I am impressed. I just wish that I had also ordered a flashlight as well.
Ordered on the 8th, received by HK post on the 10th and in my hands in Florida on the 16th. The best service that I have ever received from China.
HKEquipment has certainly moved up near the top of my preferred dealer list.
mine came today as well - i got the sf5 flashlight - hkequipment included a thank you to me for doing the group buy along with a fenix e01 bonus light - i had no idea they were going to do this and it was a very nice gesture
You deserve it.
It flickers on medium 2 and turbo but not high. Regulation issue or the cell? :~
sounds like a potential issue - i would try charging the cell and see what happens… or perhaps try a different battery to confirm - if it persists email hkequipment for a RMA
Stung for custom charges that almost negate the GB discount, but still worth it!
Only had the lights a few minutes but i like them, seem like nice, solid, ‘no fuss get the job done’ lights, and if i’d realised how easy it was to change the emitters i probably would have bought more for gifting. Might still do.
Thanks again jmpaul, and glad you got a little bonus.
One question, does anyone know how to remove the lens? (as in the actual piece of glass.) It looks like i need to unscrew the silver metal bezel, but can’t see any way to grip it.
I did try again after charging the cell and then ran it on turbo. The low frequency flickering happened after 17 minutes. Pulled out the cell and the voltage was 3.8V. I’m not sure what to do now just waiting for my new cell to arrive.
I ordered some AW 16340 cells from Lighthound 
I missed such a useful action … :weary:
PS. sent pm
I think you can still get it if you contact them. They will want more sales.
… and more money :cowboy_hat_face:
[quote=harry218]
Ok, thank you!
PS. My SG5nw:
Got my SG3NW and SF3 NW today!
SG3NW is awesome and perfect except some minor cosmetic “dings”, and has already eaten its o’ring, but that’s not really a problem.
SF3 NW is ok except it looks like it will be eating o’rings quickly too, but there is a small darker spot on the led, and the lowest mode is flickering 
It will probably receive a new led very soon, I also got some XM-L2 T4 7A4 this morning 
I think the SG3 will replace my Zebralight SC31fc for now :party: