It looks like the same transistor failed in both cases, which makes me think a design error or the wrong part was selected for the task.
It could have shorted internally and provided a current drain path to deplete the cell (and get hot in the process).
Excellent reporting. I’ll skip this model and stock the Convoy T2 instead. Loved the SP10S though
Such a shame
Noticed the same behavior in my sample. Started at 22 degrees C, went to 28 deg. C in about 25 minutes.
The SP10S was a good host and driver with a crap UI. The V3 should have been the same host and driver with new firmware to update the UI.
Does anyone have a schematic or circuit details of the horizontal board to which the switch board (vertical) is soldered? To identify that part of the circuit and the part number of the device that burns up.
If it is a FET, then it needs a pull-down to ensure that it shuts off; FETs can remain ON even with the gate signal removed due to the capacitance in the FET, that’s why they need to be driven to the OFF state and not just left floating.
If someone wants to send me a board then i will trace it out and send it back repaired.
TIFisher does your sample work with both AA and 14500?
Mine never worked with AA.
100% agree with you jasontheguitarist. The UI was the only thing that needed to change.
I will say that the beam on the V3 is slightly improved over previous models. It’s a bit bigger spot with a more blended spill. Ofcourse this is just my opinion/preference in a light like this.
Was the light OFF or ON when the temperature increased by 6° Celsius (~11° Fahrenheit) in ~25 minutes and what level of brightness was selected if the light was ON?
I have one SP10V3 from AmazonUS (shipped from a warehouse in the State of Illinois) and another SP10V3 arriving today from AmazonUS (shipped from a warehouse in the State of Washington).
No. Won’t turn on with NIMH either.
This behavior manifests while the light is OFF, tail cap tightened, sitting idle.
I bought the Sp10v3 on the Sofirn Official Shop on Aliexpress. I opened a dispute and now they replied :
“First, check that the insulating sheet placed on the battery needs to be removed to conduct normal conduction. Second, the test battery can be used normally (you can use other brands of batteries). Use a wire to test whether it can light up. If it does, it means that the tail switch can’t conduct electricity. Just send a switch. Fourth, use alcohol to clean the exposed areas on both ends of the barrel, including the exposed areas of the steps inside the tail cover, and then try again. Try to light up”
What should i write them now ? Should i just give them a link to this thread ?
Take a video of it not working with an AA battery and say it’s a faulty driver.
You could message the Sofirn member above and they should then be able to get in contact with the AliExpress team, but only if you don’t get anywhere with the video
I attached a video when opened the dispute. Ok Thanks, i message them.
Just this.
I don’t understand why manufacturers don’t simply refine their products instead of starting from scratch and screwing up from a different direction.
FWIW I ordered this light from Amazon a few days ago. So far I have not had any problems using the included cell.
Indeed, i was looking at getting one but now am going to stay away.
I waited too long to upgrade my lights, the 4AA is discontinued, this 1AA is defective 
The SF11 4x AA was a bad design since it had a floating shelf. The only thing connecting the shelf to the body was two screws, all around the sides aren’t touching anything
Egads. So perhaps better i never got one.
Are there any other 4AA lights you can recommend?
I purchased 30pcs to sell, but seems to be okay since it’s only low output.
That’s the only 4x AA model I’ve used, everything else is lithium
Supposed to be 1050 lumens, about 10W of power so still a fair bit.
BTW Sofirn’s site currently says
I put thermal grease right around the sides and didn’t heat up anymore than without it, so doesn’t seem to be an issue. It has a 3 minute stepdown to High which would help. I measured 1000 lumens, Sofirn’s early models were so accurate on the ratings.
Sounds like a great deal lol
I have an old light with a separate pill that is press fit into place with a lot more contact than two screws, when tested it had a lot of lumen sag becasue of the poor contact. Thermal paste also did not help much. So i find it hard to believe that two screws is good enough and would not be improved by not being a solid one piece setup.
And that is a weird offer from sofirn. You may be the about only one who might take advantage of it since you sell flashlights.