Addendum to my instructions on the magnetic ring removal. The [battery tube] @PiercingTheDarkness mentions is the long piece that the battery is installed in, NOT the front part you need to remove to take the magnetic ring off. The front threads on the battery tube are not anodized.
The part in front of that has anodized threads and you can grease it well, and probably ought to.
Great information. Thanks yāall.
Did a burn test on high in a tub of water. A 2400mA (tested, not protected) cell lasted 90+ minutes on high. At the end it started blinking for a bit, then simply went out. Seems to be an inherent low voltage cut-off. Cell measured 2,91v when checked.
Finally got mine. Very nice flashlight for the price (recent discount). It is a bummer that thereās no lockout. While the selector ring is notched, it could be rotated by accident. I donāt plan on changing the emitter. The glass has a film on the insideā¦ but itās more of an annoyanceāI doubt itās affecting the lumens output much. No knurling except for the control ring, so I added a bicycle inner tube segment to the body. It was tough getting it on! Took me about 30 mins while I watched a TV program. But now it has good grip while still looking nice. Looking forward to testing this while snorkeling this summer.
Above.
āā No knurling except for the control ring, so I added a bicycle inner tube segment to the body. It was tough getting it on! Took me about 30 mins while I watched a TV program. But now it has good grip while still looking nice.āā
For that, I have lotsa shrink wrap tubing of differing dia. Colour, lengths,
from Fishing rod MFG days.
Just remove head unit. tail cap. Cut and slide on the Wrap, in colour to suit.
Then warm it up with a heat torch.
Carefulā¦ Ally holds heat for loonger.
OR Self amalg tape does same job.
But tends to UNwrap from finishing end if not, (me) O,ringed down to hold.
Small overstretched O ring.
I often add a coupla small thin o rings to any torch with grooves round casing
for extra grip too. (ie S2) and early shiny C8ās.
Yes, heat shrink wrap tubing is possible, but the bicycle inner tube is more resilient & grippy, in my experience. It came out well actually. O-rings wonāt hold well because of the curvatureā¦ but the bicycle inner tube is on so tight, not worried. Actually, one could cut it a little short and then use a single wrap of grip tape. The only problem with grip tape is that over time, the material will shift and expose a sticky adhesive.
For people who want some more info. YouTube is full of instruction videoās of nice young ladies who show you how to shrink wrap a banana.
And Macka17: congratulations with your birthday. Please take good care of yourself and the missus.
Thankās Henk.
Hey all.
My 03 came Monday. I installed a Samsung 30Q. All good. works fine.
Yesterday I stripped and cleaned all 4 threads, then used w/proof grease on the 3 recommended.
Hmmm. NO Light now.
Sw rotates.
Multi on base of battery and side of case shows the 4+v. With NO show on exposed led.
Rotating sw shows voltage on each click, on batt base/case side contacts.
Changed another full charged Samsung30Q, but still no show on led.
Iām no sparky just a fiddler. Have I stuffed it somehow?
Clean the grease off the threads from the barrel, where the threads are not anodized. You may have insulated the contact surfaces.
What grease did you use, specifically? The O-rings make the seals, the grease does not. The grease facilitates screwing the surfaces together. Grease should be used sparingly. This is not a wheel bearing.
Iām still really happy with this as a general purpose flashlight. Ideal to lend to people whoād be baffled by BLF-type user interfaces.
And I have to say I even get lost in the multiple-click UIs myself every few weeks and have to pull out the printed instructions.
This simple clickstop ring for three brightness settings is soooo simple.
Now I gotta mod an amber LED into it ā¦.
Yes BUT you have to remember which way you rotate it. It is a weakness and a strength in that the ring will rotate either way with no stops. If you turn it one way itās on low, the other way itās on high and since you forgot which way to turn it but you wanted low, your night vision is now toast. 
But you can start on high or low, as long as you remember which way to turn it:-)
Great light, still loving it! Sadly it appears that Sofirn discontinued it.
As a diving light I donāt think divers would care their night vision in the water, most always want the brightest setting.
The SD03 isnāt as good as you think. As a dealer I purchased 45pcs and have had nothing but trouble. The threads at both ends are all that make a connection, thereās no retaining rings on this model. Continuously you remove the tail cap for batteries and it becomes very dirty causing a connection problem. Iāve had to clean all the threads with electrical cleaner before selling to stop the light flickering, spent around 10 hrs cleaning, sometimes multiple times to get a reliable connection, had to sell for near cost to get rid of them
Wow, no issues with mine. I leave it by the back door at our coast place to check for critters nightly when I let the dog out. A paint lid will rust in a week down there if left outside and I see nothing wrong with the light.
I havenāt had any returns, but to get them working properly they needed a thorough clean. I have a 30 x 30cm microfiber cloth black from how dirty the threads were.
I reckon I received old stock that perhaps had been sitting for awhile.
My SD03 has started blinking with fully charged batteries. Any help?
With some time our Sofirn lights faults too with that issuesā¦ have you try with new batteries?
Looks like Sofirn forgot that they have already used the āSD03ā model number before.
They just released another diving flashlight named āSD03ā, but itās a different lightā¦
When searching for āSD03ā reviews, it now gets confusing because 2 same model numbers but different lights.
Where did you buy the new SD03? Itās not listed in the Sofirn store yet (at least for me in the EU).
Never heard of the shop before so not sure if itās genuine but the specs are here link
Shopee & Lazada are for Southeast Asian market (where Iām located).
But the SD03 is also listed in AliExpress: