[Technical discussions] Sofirn SP35 - SST40, 21700 size, buck driver

Wonder why no hoopla about the roll out of a new light with this one?

The SC31 Pro is also 2000 lumens and 5000K: 23.47€ 34% OFF|Sofirn sc31 pro leistungs starke 2000lm 2,0 taschenlampe sst40 5v/2a tragbare wiederauf ladbare led laterne usb c fackel anduril|LED-Taschenlampen| - AliExpress

Unless it’s actually below 2000 lumens with that figure only applying to the 6500K version.

Yeah, only applies to the 6500K. Most brands won’t correct the lumen value for their tint selection.

Leds are actually blue and so there’s a layer of phosphor to help block out the blue, the warmer the tint, the thicker the layer which also lowers the lumens

[quote=31337hacker]

Funny thing is, those pictures show a 4000 mAh 18650. Is there a legitimate 18650 with that capacity?

I do suspect that it will actually ship with a 4000 mAh 21700.

Would be nice to also include an adapter tube, like the the Sofirn-made Astrolux EC lights come bundled with, but no mention of one so it doesn’t appear likely.

[quote=TheIntruder]

Most likely a computerized label and without thinking put 18650.

Max capacity is 3600 for the 18650 size

Gotcha.

The first video has landed:

Looks pretty good.

Hope somebody eventually tests how well the regulation works.

Is this it?

https://sofirnlight.com/sofirn-sp35-21700-usb-rechargeable-flashlight-super-bright-2000-lumen-sst40-led-torch-light-p0165-s0066.html

No step down, is that better?

I have a test unit and the regulated output does a good job. The first batch is a big fail when the ATR doesn’t work, mine hit 80°C after 5 minutes on Turbo.

Beam profile has artifacts that I hate though, there’s a circle around the outer hotspot and you can see the corners of the SST40 as slight dark spots in the center of the hotspot. Most of us will notice but the average user will be quite happy. The SC31 Pro has the same smooth reflector and SST40 and it doesn’t show these artifacts. I think they should change to an OP reflector as a fix.

Just about to go outside for some beamshots on a decent camera, video should be up by tomorrow night.

I don’t like the tail cap being a larger diameter, the built up sides make tail standing no good unless it’s a completely smooth and level surface. Should of just had the same tail as the SP32A and smoothed/rounded off the the sharp edges.

The first batch has a bug where the thermal regulation doesn’t work. Wait for the next batch if you prefer it.

I love full manual control for extended use, so this is a bug I like. Without ATR working, High mode ran for 2 hrs 13 minutes at a stable 860 lumens before shutting off at 2.80 volts

Funtastic,

Is the tint on your sample version 5000k or 6500k?
Also in the Sofirn web page listing it now has 2 battery options, 4000mAh and 5000mAh?
Do not know of 5000mAh in 21700 from Sofirn
No step down is tempting. Love that run time on High as well, have a new appreciation of current control buck drivers.

Also do you know if the ones that are being sold on Amazon will be ver 2?
They say “Arrives: Jan 14 - Feb 5” so they are giving lots of lead time which may mean new version.
Thanks!

Keith

I ordered one from Amazon a couple days ago and can confirm that it’s shipping from China. I’ll do a full runtime test when it gets here. Hopefully it’ll be like other Sofirn items I’ve ordered lately and it’ll take ~2 weeks to get here.

I'd like it, but... That button sure looks like a driver mount style - agree, Sofirn likes this style but they did do it the right way with the SC31B and SC31 Pro.

Ohh - with my SC31 Pro, I swapped the 6500K SST-40 for a 5000K SST-40. I don't see any loss in output. The output actually went up: 2100 (calibrated) at start now, running at about 9 amps (was 1980 at ~8 amps). I don't even bother with 30 sec measurements on lights like this .

With these LED's, the output is governed by the binning, and I didn't see the available 5000K's binned any lower, or much lower? Least I can recall. Even with the old XPL's, the bins of high NW's (5000K) matched the CW bins (XPL V6's, like used in the Q8). You drop bins big time for high CRI, or warm tints - that they haven't improved on yet.

I used a Samsung 40T for the following

High runtime - 2 hrs 13 min - maxed out at 60°C with room temp at 24°C

Turbo (no cooling) until hitting 80°C

Check out the runtime graph on the OP. You can see that 1750 ish lumens was the starting point, why has Sofirn rated it at 2000 then.

My measurements at 30 sec

1750 turbo
868 High
364 Med
114 Low
6 Eco
Moon (not measured)

We’ve often thought Sofirn’s calibration was off, what if it isn’t, and they’re purposely bumping up the numbers for marketing.

For those interested in buying SP35, there's a new sales thread online...

Hey funtastic,

I have one of the first SP35 and I agree with your assessment that the beam is quite not nice to look at. You wrote that Sofirn already updated the reflector, do you know if we can somehow get our hands on those new ones? I am quite happy with my buggy SP35 without thermal regulation though, would love to have a smoother beam.

I was told by Barry that the old reflector was only used on the first 100pcs. I don’t think enough people have received their SP35’s to know if it has been fixed.

I suggested using an OP reflector but Barry said to wait and see if the new reflector would be okay.

I’ll try and remember to ask Sofirn if they’ll sell the new reflectors separate

That would be very much appreciated :slight_smile:

I ordered my SP35 back in Nov/Dec I believe when they didn’t had them in stock yet to send out. Arrived shortly after Christmas here, so I am pretty sure I have one of the first ones. No thermal regulation, gets pretty hot :smiley:

I ordered the SP35 kit from Amazon on 06JAN21 and it arrived on 14JAN21. Kit was complete, with 21700 4000mAh battery, clip, lanyard, and O-rings (o-rings are in the small ziplock bag with the lanyard, look closely). I’m impressed with the output of this Sofirn, it lit up my 2-acre pasture (0.8 hectare for the rest of the world) very well. Eco mode is sufficient for me to walk inside my house with all other lights off. UI works as per owners manual, I like the double-click to go from Off to Turbo mode.