Sofirn C8F host. 21700 C8F Available

Sorry, voting is over. They chose 21700. Now you have to start all over buying batteries in this new size. Lol

Are there clicky-less tailcaps available?

Yes

No, there’s only the one at the moment. There is a chance they will offer a flat tailcap in the future, though.

It sounds like people are starting to receive their C8F 21700 lights! I’ve been interested in this light and have a few questions:

1) I couldn’t find any direct links or discount codes for the 21700 version in this thread. Is Aliexpress the best place to order? Is $33 (current price) the best deal?

2) What is the tint? johnkey68’s picture shows 4850k but I don’t see this listed anywhere else, is that accurate?

3) What discharge current is required of the 21700 to support max lumens? I already own two legit Samsung 48G 21700 4800mah which support 9.6A, is that enough discharge current? I noticed for $6 you can add the Sofirn 21700 4000mah, is this a quality cell?

4) Any complaints from people who have already received their lights? Looks like a good price for a 21700 triple!

Thanks all.

  1. Yes, $33 is the best price right now.

2. The tint is 5350K to 5700K. John modified his.

3. There is no minimum continous discharge rating for this light. That is a rating for batteries. This light is direct drive so the amount of amperage it uses will vary depending on the battery used. The 48G should be fine. It may not give the max output, though. For that you need maybe a Samsung 30T. I would not sweat it, though. If your only going by eye, its hard to see the difference.

I suspect Sofirns 4000mah is the LISHEN LR2170SA which is what Liitokala uses. I have no confirmation of that though. They only told me it was made by a company who makes batteries for cars.

I ordered one of their batteries and will test it out once it arrives.

4. I’ve only heard a few small things. The ramping speed is not smooth like NarsilM. It goes from moonlight to 50 lumens real quick.

One person was getting less output than their 18650 version using the same 18650 cell to test for each. I’m not sure what is happening here. Maybe the shorter 18650 is not pushing the springs very hard and adding resistance?

So far only a handful of people have recieved them, so there’s no real tests or reviews yet.

I’ve received the Sofirn C8F 21700 version that I ordered from Sofirn’s AliExpress store, so I’ll write only based on my experience.

1) There doesn’t seem to be a discount code, however, there may sometimes be multiple (2 or 3) product links for some of the more popular Sofirn products, and sometimes, one listing might be slightly cheaper than the other listing. Be sure to check they are the same item (as of last checking, the C8F 21700 has only 1 listing, but other Sofirn lights usually have at least 2 listings… just my observation)

If you’ve been purchasing from AliExpress for some time, you may notice they have 3 types of discounts (and they can be cumulative):
a) AliExpress Select coupons = you are entitled to use the Select coupon to get a discount when you purchase over a certain amount
(how to get AliExpress Select coupons - use your ‘coins’ to exchange them, and also some other ‘activities’ on the phone app allows you to get that)
(you need to have the Select coupon first, before you can apply the discount)
b) store discount = this is a straight discount of a certain xx amount when you purchase yy amount (it’s automatic, you don’t have to do anything)
c) seller discount = you just grab this coupon from the store, they are free to get (but have a limit, eg. you can get this type of coupon once every how many days or weeks), it’s applied in the same way as the Select coupon (xx discount when you purchase yy amount)

by judiciously using the above methods, you can achieve your desired discounts (well, the key is for you to “spend” more money to get more discounts…)

2) Most Sofirn lights seem to list 5350-5750K as their tint, and I’ve sometimes ordered same Sofirn light but they appear slightly different tint, but likely within the 5350-5750K. As I don’t have something to check color temperature, I notice that the earlier Sofirn C8F (I got before) compared to the Sofirn C8F 21700 (which I just got) = in my specific samples, both of them seem to be somewhat in the cool neutral-white, but my Sofirn C8F seems to have a very slightly ‘rosier’ tint than the one on the C8F 21700. I believe this is just due to sample differences and another C8F 21700 might possibly also have the “slightly rosier’ tint too.

3) I think a cell with at least 10 amps or more continuous discharge current would be best. I did include the Sofirn 21700 since such batteries are very hard to find and expensive in our country (and most foreign online stores do not ship batteries to my country; so I now have to buy batteries with flashlights if possible). I used MC3000 to test capacity of the Sofirn 4000mAh 21700 and it got a bit over 4000mAh (drain to 2.75v cut-off). Since I don’t have another 21700 at the moment, I can’t say if it’s better or worse, but it appears to be a good battery — it’s flat-top and unprotected. The IR measurement from the MC3000 for the Sofirn 4000mAh 21700 is around 25mOhms (adjusting the battery in my MC3000 can slightly affect the IR reading).

4) issues? Well, I think someone above also has both the previous C8F (18650) and the C8F 21700. In my unscientific observation / testing, it seems that my C8F (18650) is slightly brighter on Turbo than the C8F 21700 on Turbo mode. Using a clamp meter, I’ve measured 10+ amps tailcap current reading on the C8F 18650 before, but on the C8F 21700, I’m getting around 7.8 amps only (I checked that the spring-bypass wires are still intact on that unit).

(note: the spring-bypass wire on my C8F 18650 seems to have just broke off, now the tailcap reading is around 7.8 amps too. As of now, I don’t have a soldering iron and the skill needed to reconnect the spring-bypass wire of my C8F 18650…).

I think ramping speed has been mentioned… it seems to work similarly as the ramping on the SP32A v2.0 — it may not be as smooth as NarsilM, but seems to be pretty good (probably around 4 seconds from min to max).

Actually, Sofirn has been using a 2C version of the XP-L2, which falls in right around the 4850 tint and is really nice. I don’t find this emitter anywhere but really like it in my Sofirn’s. :wink:

Whether or not they’re still using this in the 21700 I cannot be certain, but it’s what they used in the previous triple C8’s. ( or it’s what their engineers told me)

That doesn’t sound right. They are using the older xpl, not xpl2, right?

2C falls squarely in the 5350K to 5700K range. A 4850K would be either a 3C or 3D.

Yes, they are using the XPL.

You must have gotten really lucky with your tint bin.

I have two versions of Sofirn C8F18650, they have different emitters, the newer version also has other anodizing - more shiny and grainy. the older C8F has a matt anodizing. older C8F has a white light color with bright pink. the newer C8F has white with a touch of yellow.I like both but I would choose the older one
now I can not compare them because I gave the newer version to my colleague

Thank you Jason and dta for the detailed responses!

I was among the first to test the triple C8, but then, my drain is bamaged so what I recall is likely to be skewed. Sorry.

Prompt please: the sealing ring of glass should be laid from the side of the bezel ring or from the side of the reflector?
1)bezel ring~~sealing ring>glass->reflector
or
2)bezel ring
glass~~>sealing ring->reflector
?

I don’t own one, but I think this picture is correct.


1)bezel ring~~sealing ring (o-ring)~~>glass->reflector

It looks like there is a groove for the O-ring to fit into on the bezel.

I concur. In most C8 flashlights, I notice they use (1) bezel ring -> o-ring -> glass -> reflector

You are best! Thank you!

Received my C8F 21700. The size is just a tiny bit larger than the 18650 version. The finish is a tad bit shinier than the mat finish on the 18650 version. Tint is a little cooler than the 18650 version, but both are pretty decent. It comes with a sleeve to allow use of 18650. Both versions come with factory spring bypasses. The following are my test results from a TA Lumen Tube calibrated with Maukka calibration lights.

C8F 21700 on Samsung 21700 30T: 2,890 lumens at 1s
C8F 21700 on Sony 18650 VTC5D: 2,500 lumens at 1s
C8F 18650 on Sony 18650 VTC5D: 3,155 lumens at 1s

This is very disappointing considering Sofirn rates the C8F 21700 version at 3,500 lumens. They rated the C8F 18650 version at 2,580 lumens only. I’m surprised why the 21700 version performs worst than the 18650 version. Usually Sofirn lumen specs are very accurate or even under rated so not sure how did they screw up so bad this time.

Sofirn C8F 21700! :smiley:

@SKV89, I have the feeling the spring bypasses are done with thinner wire, and aren’t done as well.

That could be the culprit, along with perhaps lower spring compression force resulting in much higher contact resistance. There could be many reasons for this.