Sofirn SC21 mini

I think the best solution to prevent accidental pocket activation might be something along the following:

  • Insert a sensor or some kind into the light that detects if anything is within an inch of the lens.
  • When you press the button to the turn the light on, the first thing that happens is the light activates the proximity sensor.
  • The light only turns on if the proximity sensor does not detect something next to the lens.

If it worked, you could have a pocket EDC light with a big easy-to-find protruding button, with no need to lock it out and no accidental pocket activation.

How to implement this? … no idea. I’m not an engineer. IR sensor maybe? Or maybe have the main LED turn on at 0.001 lumen moonlight and if the sensor registers a change in brightness when that happens, then the light does not turn on in higher power modes?

This would complicate the hardware, and also be set off by anything in front of the lens on purpose, such as a filter or diffuser. The basic issue is the pushbutton so I hope it is possible to fix the pushbutton.

The best thing is to just turn it a quarter turn to electrically de attach the spring side.

That certainly works.

But one of the nice things about a pocket EDC is how it can be yanked out of the pocket with one hand to instantly give light.

If you use tailcap lockout you probably need 2-hands to unlock it. This slows down the process and removes much of the convenience.

That sounds like it relies on insulation from the anodization in the threads, so a tiny pinhole could defeat it. Doesn’t seem good. In fact one reason I like titanium lights is they’re not anodized, so the threads give an additional conductance path.

Got my Sofirn SC21 today.

My initial impressions:

What I like:

  • Fairly good output for a 16340 light.
  • Small, but not the smallest 16340 light. The Eagletac D25C is smaller. The Wowtac W1 is much smaller (and also has onboard charging).
  • Rubber cap for charging port is well done. It fits securely in its slot and doesn’t feel flimsy or too thin.
  • Feels good in hand.
  • Looks cute
  • Low cost

What I don’t like:

  • Due to protruding button, the risk of accidental pocket activation is high. Using mechanical or electronic lockout is a must when pocket-EDC’ing this light.
  • I do not like the clip. It’s not that the clip is poorly implemented. It’s ok. It stays on the light better than the similar clip on my Thrunite T1. However, I’m not a fan of bi-directional clips since they tend to be harder to use and contain unneeded mass. I also think a black-colored clip would look a bit nicer on this light.
  • The tailcap magnet is not removable. This is surprising, because the tailcap spring is of the type commonly used with removable magnets, but they glued the magnet.
  • The bezel is glued, making modding difficult.

Managed to break the thread locker and unscrew the bezel without damaging the anodizing. Not too difficult to remove. Thankfully they didn’t use Jetbeam levels of threadlocker.

Inside is an 18mm copper star.

How does it hold up performance wise? Quick drop from high or does it seem to be a good EDC in cooler conditions for 20-60 mins?

Is the driver compatible with sc31pro host?

I think there is significant drain while 4click lock. Some readings recently, torch not used apart from checking it’s 4click locked.

Locked
11:11 26-Oct-21
SC21 3.973
09:40 28-Oct-21
SC21 3.808
15:14 30-Oct-21
SC21 3.665

Unlocked
10:24 01-Nov-21
SC21 3.666

Locked
15:06 03-Nov-21
SC21 3.602

Recharging to test again.

After reading your report, I decided to try measuring the idle drain on my Sofirn SC21:
(maybe someone else can also try confirm testing, as my meter and measuring may not be that precise)

while Off (not Locked-out): 0.07mA
while Off and in Lock-out mode: 2.8mA (this seems fairly high parasitic drain)

It seems Lockout mode does consume a fairly high amount of power

(Side comment: I can think of the Skilhunt M150 which also had a similar issue:
while Off, the idle drain is OK, but when in Lock-out mode, it also had high parasitic drain

(Skilhunt M150 also uses around 4mA when in Lockout mode, but when not Locked out, it has very load idle current)

I never use lockout modes myself, but that seems significant and a cause for concern.

Hopefully Barry or someone else from Sofirn can comment and/or look into it?

Kinda like The Cave Man (EA8). Normal “off” is actually standby mode (blinky button-switch), and will eat through those alkaleaks in a hurry, often just days. Proper off is extremely low drain, lasts a looooong time.

Just easier to pull the cells entirely to not screw up the modes, and I’d never leave alkaleaks in a pricey light at all anyway, so…

I have two SC21s and have experienced the high drain while using electronic lockout with both. From fully charged batteries to will not even come on in about two weeks. Put the batteries in my charger and sure enough, voltage has dropped to the point where they show zero of four bars. This is not an intermittent problem, but happens consistently. I have commented on this earlier. Then there is the concern with the protruding (and easily activated) power button, An otherwise nicely priced and good performing light is held back by these issues.

anyone have this in the 2700k tint ? seems like a good deal getting below 3000k tint in this kind of light. Shame about the high drain issues that shouldnt happen.

I had the same problem. It’s kept me from using the light since I can’t trust that it won’t just kill batteries for fun.

Just tested my SC21 using a benchtop power supply set to 4.20VDC and a Tektronix TX3 DMM wired inline.
Light off= 41uA.
Light in lockout= 60uA.
I watched it for a while and the current stayed steady, no pulses or change in current.
I’m topping up the battery now and I will leave it in lock out for a week to see what happens.

I got one a little while ago and I really like it. It’s quite small and fits perfectly into a small gear pouch like it was made for it. Yeah, the battery life isn’t quite the same compared to a 18350, but it’s easy to charge with one of the zillion charging cables I’ve got laying around these days. I just think it hits above its weight class for a very easy to carry light with quality construction.

Anyone tried to open the SC21 up? mine just stopped working and its not from the battery side. The led and copper plate seems fine. Must be driver/ charging are. Does not want to be unscrewed. starting to wonder if they have glued it in place…

I opened one a while back. There was a huge amount of red loctite. I had to sandwich it between two pieces of wood at the flat part of the cooling fins, and then use locking pliers with leather on the bezel.