I agree with you Jos. This recognition might be the result we now see with Sofirn's SP36S which basically is a simplified SP36 BLF Andúril edition, coming with a less complex user interface and a more conservative thermal management (2min timer, 55°C ATR). And that is also the reason why I have proposed a thermal regulation to Sofirn that is fair to all sides and addresses both requirements for enthusiasts and apprehensions of muggles. Being more flexible with user-defined thresholds flashoholics will be able to unleash the full power whereas - on default - muggles can safely operate the light with moderate settings.
Ordered a SD05 and put my trusty protected Trustfire 18650 battery in. I really like the form factor, the build and the magnetic ring, but i’ve got a problem:
It does work on low mode and middle mode, but as soon as I turn on high the lamp turns most of the time (not always!) almost immediately off. I have to anscrew the tailcap and screw it back on and then it starts over again.
Is my battery showing it’s age (5 years now), do 18650 not fit properly or is it a problem with the torch?
I’d suspect the battery.
Battery, especially if it’s protected and high-mode just draws too much current. That, or it’s just old and its too-high internal resistance causes too much voltage-sag and the light cuts out under lvp.
Some lights you can get away with laptop-pulls and other rejects, others nope.
There may be a problem with the protected battery. The high current consumption is 5.7 amps. Protection disconnects the battery. I also have SD05 and I measured the current draw.
Get a 21700 battery from https://eu.nkon.nl/ or at least an 18650 with a 10A continuous discharge rating. The 5.7A load is tripping the protection and the cell probably can’t handle the load either, Trustfire always overstated their cells capabilities one way or another (at least they are not Ultrafire).
I measured the current with the Sofirn 21700 battery that I bought with the flashlight. The battery was fully charged to 4.2 volts.
The come-with battery works (wurks?) quite nicely. You got the light-only, not the kit? Tsk…
Yep, just the light. Delivering to Germany you have to pay tax and customs for everything over round-a-about 26 EUR so as a kit the torch was a lot more expensive. I already ordered a Sofirn 21700 battery separately but it hasn’t arrived yet.
But it seems to be the old trustfire battery, so i can calm down. 
This light will not allow current over 7.1A so you don't have to use a protected cell.
This is an awesome light the perfect size and i think its dang near as bright as both of my Sofirn C8F’s and my sp33 , by the way my ring does not rattle at all.
^THIS The most important feature of a dive light. The Sofirn is inexpensive, so it it works for quite some time before the stuff rusts out……I don’t think you get high quality from China at that price. Jus sayin…mines inbound as we speak.
Sharks Bay, Egypt
Daytime shot, depth - 10-12 m
An actual dive shot, nice! Looks like fun.
Hi gchart! I got my SD05 a couple of days ago, and decided to piggy-back on your topic a bit. I bought it mainly as a diving light (I scuba dive every now and then), and while I'm very impressed with build quality and light output, the timer + temperature is a major flaw IMHO. Thermal throttling thankfully is almost a non issue underwater, but the timer makes it super annoying to reset the light every 3 minutes, which tends to be quite difficult in drysuit gloves. I decided to tear the light down (driver board comes off easily once you unsolder the wires from the front) to see if re-programming the driver would be possible, as that would also give me a chance to adjust the levels (I find the difference between Low and Medium to be too subtle, and it's a shame it's missing a strobe mode). Unfortunately it's not a simple ATTiny based driver, but something a lot more complex. Haven't seen any driver pictures on the forums yet, so here they are:
https://imgur.com/a/CEJYJYj (higher resolution in the imgur album)
As far as I can tell, the main MCU is Microchip F1824, and clearly visible there's a boost converter, namely TPS61088. The modes are selected thanks to Hall effect sensors (3 of them) that respond to the magnetic ring.
Have you seen anyone writing firmware for such MCUs here? I can reverse engineer the schematics for the driver board, but I'm lost as far as programming is concerned. I feel like building a new driver based on an ATTiny would be much easier, although I'm not sure how to implement the Hall effect sensors in the firmware.
Would you be interested in helping to improve this light a bit? I've seen your designs (2 of my Convoys are running your tailswitch light boards) and I feel like you're the right person to ask.
Would love to hear your thoughts!
Interesting… I wanted to take over apart (the first one I received appears to have a defective driver, it doesn’t turn on), but it seems like the battery tube is glued to the head. Was yours not glued?
There’s a couple people here that write firmware for PIC, but not many (tterev3 comes to mind). I could probably pick up the skills, but it’s not going to happen at the moment.
The best I could probably do at the moment would be to create an adapter board and piggyback a attiny816 in place of the PIC. Would take some probing around to confirm the function of each pin.
Battery tube has double orings and a normal thread towards the head, it seems like there was some sort of thread locker on there as well, but if you grip it tight it’s going to give in eventually. After that you just need to desolder the wires from the LED and you can take the driver out.
I’ll be happy to help in any way I can - I’ll start mapping the pins and maybe reconstruct the wiring diagram. It really is a great light, but this timer/ATR fiasco really grinds my gears. I’m open to any suggestions, so if you want me to do something, let me know!
Agreed. Timer step down in a dive light is one of the dumbest things I’ve heard of. I generally really like Sofirn stuff, but that was a big oversight on this light.
Mapping pins would be helpful. I’ll have another go at getting my light open.
Happy Holidays!
Thanks for the board shots aabatteries, they helped me figure out a few things. I replaced the current limit resistor with a 100k one as per their data sheet. Not quite sure it made any difference but ill add a pic once I have it apart again.
The big difference was adding a 4000k xhp70.2 in place of the XHP50. Efficiency is higher per Texas Aces (Thanks TA!) output tests, and it fits perfectly with no plastic ring.
Beam shots and such:
XHP70.2 Modded Sofirn SD-05 XHP70.2 Modded Sofirn SD-05 - Album on Imgur
Shot of the reflector:
Shot at ISO 100, 1/20 exposure on OP7 Pro at 2.5 feet.
Now trying to change duty cycle by adjusting feedback. I think timer is dictated by a capacitor if im not mistaken.
I’ve just picked up an SD05 in December and bought a Samsung 50E 21700 to run it with. I took it out mountain biking the other night to test its use as a bar mounted light and didn’t notice any stepdown behavior at all. I am confused as no one has mentioned that Sofirn revised this timed stepdown (that I’ve seen). It was about 24ºF outside and I purposely rode with the light set to high for a good straight 7+ minutes (thought it was longer, but my video shows just over 7 minutes) looking to spot the stepdown. I kept my helmet mounted light off to be sure to see the stepdown too. After that 7 minute segment I then switched the light to medium and saw a noticable drop in output. I then switched back to high and believe the output went right back up to where it was. I will say that high doesn’t look like 2,500 lumens to me comparing it side by side with +/- 1,500 and 2,000 lumen bike lights (which I’ve measured myself in my DIY sphere), but maybe it’s just “optical illusion” and I’m not a good judge of output by eye. I’ve not done any tailcap current testing or sphere testing (yet), so perhaps I need to in order to figure out what is going on (let ’er run over 3 minutes with and without a fan blowing to see if it steps down and how much if it does). Does anybody have any information on Sofirn getting rid of this stepdown?
Also, am I correct that this light is using the 6V version of the XHP50.2 with a boost driver providing regulated output? Am I correct that there (so far) has only been one version of this SD05? I think I was confusing the SD05 with the SP33 thinking the light had been revised to the 3V XHP50.2 with an FET driver.
I don’t particularly light the emitter tint (looks too cool to me and not what I’d call neutral white at all - not even the cooler side of neutral white), so what do you think about swapping in a /- 4000k XHP70.2 like shown above? What should I expect after the emitter swap as far as output lumens and runtime and also heat? Since this isn’t just to be a “wow light” but potentially as a bar light during/-2hr mountain bike rides (mixing medium & high mode use), does this sound wise or not?
Here is a beamshot pic from the other night with the light on high (taken before the ride even started, so on a fresh battery). White balance is slightly off, so it appears slightly cooler than it looked in reality:
To compare, here is a Sofirn SP40 (4000k version) on Turbo (decent full battery, but not a high performance cell):
-Garry