The cells are in parallel, not series. But even when charging cells in parallel, it is important to use similar cells. Because, like you said, the charger sees the cells as a group. However, from what I’ve read, the Sofirn cells have historically been pretty decent cells, not low quality.
I’m glad you posted this, though, because I actually just ordered a SP36S last week. I’ll do some poking and prodding with the DMM with some of my USB-C cords and power supplies when it shows up.
It’s really not that surprising. 12v 2amp is 24 watt. Heck, most household light bulbs are only 6 watt these days. That’s plenty of power to fail spectacularly.
You’re not working around the stuff 8 hours a day. You were exposed for what… a minute? You’ll live. Nasty crap smells bad, and while it’s not good for you, everything is about dose. A small amount won’t hurt you. If you got a blast of a lithium-ion fire, that would be worse, but your batteries were fine.
The smell will clear in a few days. If you stick your nose up to the area, you’ll probably smell it for months or years. Some of that is real, some of it is just your imagination exaggerating things. Just keep your nose out of it, and you’ll probably never notice it.
Send the light back to Amazon and get a refund. Sure, it would be cool to tell Sofirn about it, but 99% chance is they won’t do anything about it other than replace your light.
Bottom line is that any high-power electronics can fail in bad ways.
Actually, it’s really not that important. Terminal voltage will be exactly the same across all cells. Higher capacity cells with higher internal resistance will self-limit as that resistance acts as a ballast. It’s like having 3 water-tanks — 1pt, 1qt, 1gal — with hoses joining all them at the bottom. They’ll all fill at their own rate, and the level in each tank will be exactly the same.
The reverse happens when discharging. Voltage will sag in lower-drain cells so they won’t discharge as fast as higher-drain cells.
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That said, and to keep from having to write a separate reply, most charging circuits pretty much use the same chipset, so there’s no real “better” or “worse” design. Same with usb chipsets (eg, voltage negotiation for usb-c).
Hell, whether it’s wifi, bluetooth, whatever, there are typically just a few chipsets to pick from. Almost no one rolls his own, as it’d just be reinventing the wheel.
Oh yeh, the version with the ’351s is the old/good one, right? 
I agree. It doesn’t sound like it’s the cable. If it was, you’d know the first time you tried to use it.
Definitely sounds like a defective light. Something went kablooie on the driver. Your options:
- Return the light to Amazon for refund.
- Contact Sofirn to let them know about the problem and to ask for repair or replacement. This might also enable Sofirn to figure out exactly what happened so they can fix it and others don’t experience the same thing.
- You could ask Sofirn for damages. I doubt they’d pay anything for just having a headache without any further medical diagnosis. But if you spend thousands of dollars on a cleaning service, you could potentially ask for reimbursement.
- If Sofirn fails to pay for damages you could try suing them. This might not be worth it if their office is not located near you. Trying to sue in another country could be a pain. Probably not worth the effort for minor damages such as caused by this. Before any litigation, it is a good idea to contact Sofirn to see how willing they are to work with you and make you whole.
- You could try sending the light to someone on this forum for dissection and analysis. I’d recommend securing a replacement or refund before doing that though.
Sofirn, like most Chinese manufacturers, is in shenzhen, chia
So is fenix and acebeam, etc …
If you are that concerned about it, you should consider making an appointment with a pulmonologist and/or an ear/nose/throat specialist.
Yeah and there is also a Ruth’s Chris and an Arby’s in my town doesn’t make them equal quality. One way or another sofirn is doing things for 1/4 the price. After owning two of the lights it’s clear to me how they are doing it. Cutting corners.
I appreciate all of the advice here. I suppose I will just send this back to Amazon and hope the smell goes away. Hopefully this doesn’t happen to anyone else. I would have gladly paid three times as much for the light if it was better quality. I’m not really sure if I should worry about contamination with burnt circuit board fumes on everything or not. It made me pretty sick yesterday, but I did inhale quite a bit of it. I’m hoping that it will have no effect unless it’s inhaled in big quantities at the same time.
In simply telling you that almost all flashlights are made in china these days specifically shenzhen
Fenix, acebeam, sofirn, klarus, olight, convoy, nitecore, etc …
They probably all come from not to many factories either
I was hoping to see some pictures. This thread is already on its 4th page…
A Fenix that I bought 10 years ago had a perfect finish, came with very nice packaging, very nice instructions and has worked flawlessly for a decade. The sofirn showed up in a weird generic box. I could probably find a dozen imperfections in the anodizing. The machining was sharp. It worked for less than 2 weeks. Many things are made in China for political and cultural reasons that are beyond the scope of a forum post I want to write. My girlfriend is actually from China, and I’ve been there a handful of times. Most of the manufacturing is done in this particular region. It’s not just limited to flashlights. Great quality and terrible quality things come out of this region of the world. Unfortunately sofirn seems to be the ladder.
I posted 11 pictures there is a link to the gallery
I see no exterior quality differences between the 5 fenix i bough and 5 sofirns ive bought
But then i havent disassembled em
Olights can explode too
https://www.reddit.com/r/guns/comments/behil7/olight_pl_mini_explode/
As to boxing … everyones favorite flashlight here, the convoy s2+ grey/black comes in a cheap cardboard box 
I think it’s also telling that both fenix and acebeam have a real warranty and real dealer network in the United States. These are people that you can get on the phone and talk to if you have a problem. I only know this because I’ve had questions about these brands not because I’ve ever had a problem. I’m sure there are other good manufacturers as well. Back in the late 90s when I was buying sure fires they seem to have pretty decent support even though an incandescent light is really not comparable to any of this stuff today. Anyway I learned a lesson with all of this. Stick to reputable, accountable manufacturers with a warranty. Even if the specs of a light look good if the price is too good to be true and the support is basically non-existent it’s not a gamble worth taking.
Acebeam from last few month
Fenix is pretty good IF and only if you buy from an authorized dealer
If you want “failures” well theres always the armytek fiasco from a few years ago
Basically youll be sticking to fenix …
Im a fenix fan and often say flashaholics ignore reliability and warranty
But the only consistently reliable dont ship to china warranty i know of is fenix and some american brands
Or anything bought from rei
Oh and sofirn does have more support than many of these cheap chinese brands, have you contacted them to inform em of the issue?
How do I contact them? I contacted the place I bought it from and actually spoke to someone on the phone at Amazon to inform them about the product. That was really the best I could do. I know I can call people when it comes to surefire, Fenix, acebeam and novatech because I have. to be honest I don’t know how good their warranties are because their products have been totally reliable for me.
Aside from all of this both of these sp36’s would get hot inconsistently on seem to step-down inconsistently. I was on the fence about keeping them before this happened but this certainly made up my mind.
Its in the instructions and the card they pack with it
Though the best way is through fbook, specifically their fbook group