New Sofirn SP33, Cree XHP 50.2: 2500 budget lumens

Sofirn was so kind to send me a test sample and I pushed this fine little light a bit: Runtime test, reverse polarity, overvoltage, undervoltage, water resistance. The light did exactly what the manufacturer states and the included 5500mAh cell beats a Keeppower 5200mAh cell. I am surprised that it tolerates 2x CR123A and still puts out a bit of light without taking damage.


Thanks for the review. Well done. Nice to see the high voltage regulation working properly with the 2 cr123a’s.

Nice Swans too…. :+1:

Swans were very relaxed this time, usually they are more agressive. I guess they liked the light too :wink:

Thanks for the great review Markus and thank you for your praising words about the German translation in the manual. :-) The mistake about the 26650/18650 runtimes has been rectified in the mean time. You can download the updated manual on my sharepoint: ► click here

Some customers get somehow confused about the stepdown behaviour of the new SP33 with less modes as the voltage drops. I'm in contact with Sofirn if they would like me to add some kind of a UI chart or stepdown illustration to their manual. This might be helpful to avoid customer complaints.



Nicely done video review!! Thank you for sharing. :+1: . A big shout out to the Swans also for their participation. :wink:


Are you behind the excellent user manual and translation? Well done! I know this kind of work takes some effort because it depends on your understanding of the system described (I did some translation work myself) and should not be done in “automatic”-mode.

Your diagramms are spot on. Especially folks who are not flashaholics can be confused by some of these elements and suspect a defect where none is. Sofirn really builds refined lights now, we will see what else they come up with.

THX a lot, Markus

THX! My wife was watching and waiting for the Swans to attack me. They can be very aggressive if they think you have food that belongs to them or if you are in their path. But this little Swan family was very relaxed. Maybe it is the time of the year and the fact that not many people are stressing them out. Those animals are quite a sight especially when they carry their newborns on their back and float proudly like a luxury yacht. Swan=big duck with an even bigger attitude.

Yes, I did the translation for the SP33 V2.0 manual as well as for some more Sofirn lights. I also try to improve the English version as far as I can if I find any mistakes or loose ends to tie up. However, feedback is greatly appreciated to make those manuals even better and easier to understand. I'm glad that Sofirn is listening to its customers and let us participate on new ideas.

Servus and best regards from Berlin, Germany to Linz, Austria

Awesome job! Did you need your lights recently in Berlin with that power failure?


No, I was (un)lucky enough to live in another part of Berlin. So, I could not run a 30 hrs stress test on my lights. :-P

But who knows....Berlin is always full of surprises...most of them anything but good. ;-)

Cheers, Thomas

Thx to the ingenious “Energiewende”, the change to unreliable weather-dependent power sources, we all might soon have a good time with our flashlights :wink: Not just in Berlin, our gas turbines in Linz already have to compensate for major power fluctuations coming from Germany threatening the grid: Die Instabilität des deutschen Stromnetzes fordert die Linz AG.

I actually highlighted this very scenario in my recent emergency backpack video right at the beginning:

Was I light I was considering, however you confirmed my deal breakers - the timed turbo. Living in Canada and temps are routinely below -!0º C in winter, thermal management is prefered.
Then the floody light with cool white. Floody for less than 20 m should be warm white (± 5000º K).

Especially in snow I would go warm white and nothing else. I recently took my floody KDLITKER E6 with very warm triple Luminus SST 20 P60 drop-in on a winter trip. It is just beautiful to have such a light source.

Other than that: How do you deal with the drain on lithium-ion batteries with ultra low temps? Do you insulate the light? Or would you prefer to carry the battery pack on the body with only the lamp itself exposed to the elements?

@ Markus
As the light heats up, so does the battery. Tried to find info on battery operating temps in the negatives, very little other than the test environment of 20º C. I have tested lights down to –30º C and all I can find are the switches are stiff.

Are u sure that the colder temps don’t reduce your batteries capacity? I certainly know that my cameras lithium-ion battery pack is way less powerful in colder weather. Electric cars have massive problems in cold weather. But of course a LED that produces much heat might change the game a bit. Interesting, need to research that.

@ Markus:
Of course the battery’s capacity (and consequently its current delivery) is reduced. A few minutes on turbo and everything is up to par. Hence no timed thermal stepdown.
On a side note; had a delivery of some goods including a few cells that took an unexpected route: Toronto to Quebec City via Salluit. A small very northern community above the arctic circle. The regional carrier, a twin prop, shuttling goods. Doubt the cargo is heated. Checked the weather and was –38º with wind chill. The cells work fine, no visible nor electrical problems.

Edit: Maybe the carrier stocks cargo along passenger area, would explain the Post’s decision to use such a route.