Help choosing 21700 battery for my Sofirn C8F

Wellp, I don’t quite understand the obsession with getting, say, 2700lm instead of 2500lm, when even side-by-side few if any people would be able to positively ascertain which one is brighter.

I’d go more for runtime (absolutely quantifiable) vs a nigh-invisible improvement in brightness.

Oh, and I got a 4pak of Sofirn 21700s from the recent sale, so I’m “invested”. :laughing:

Yeah, same here Lightbringer…. I’m more into longer run time myself. :wink:

How much was that “4pak” on sale Lightbringer??
Sorry I missed that…… :person_facepalming:

Apparently <16bux on 11-11. Hang on…

Ah, here ya go…

Thanks all of you for your advices, especially hiuintahs, your post is very useful.
I think I’ll stick with Sofirm for the battery and will look for a good charger.

Hey that’s great. I think the Samsung 40T is also a good fit. If I could easily find another Sofirn 4000mAh battery, I’d go with that too. A 50E battery should be arriving soon and will have a chance to check that out.

I ended up buying the Miboxer C4 Upgrade charger. I thought it was a good value. I posted a picture of the Sofirn 21700 in it here:
Charger for 21700 or 20700 (post #22)

I have 4 of the Sofirn 21700’s I’ll sell you. $4 bucks each plus what ever 1st Class mail is. I bought them for the Fireflies E07 that pulls 20A, and they just don’t work as well as the 30T does. Brightness is a noticeable difference. But for lower drain, they are an excellent cell.

Thanks Lightbringer, sorry for my late reply; looks like some kinda ‘deal’ is still going on. I picked up 4 for just under $16. :open_mouth:
Again, appreciate the info & links. :+1:

Sofirn 21700

Thanks RobertB, but I ordered THESE last night after LB sene those links.
Getting em’ from you would have saved the ‘China Connection’ shipping wait though. :wink: Again, thanks anyway for the offer…. :+1:

Oh yeah, if anyone is looking for a good, but inexpensive; charger for their 21700 batteries. Here is a Xtar 2A single bay I can vouch for.

.

And if you need a good USB Wall Adapter, here you go….

How do you know? Ive asked Sofirn but they said irs not a Samsung 40T, the cell they say is 40Amps wich i dont believe.

I got me a Samsung 50E in the mail today. I charged it up along with topping off the Sofirn battery. I checked in my makeshift lightbox, the lux figure for each battery. Naturally, I expected to see a slightly lower reading with the 50E at the turbo level……………which I did.

And I expected to see the same output at the lower levels regardless of what battery was installed………….but instead what I saw was a lower level with the 50E battery at all levels. At the low level (not the moon mode……just level one), I’m getting 410 lux in my light box (about 7 lumens) with the 50E. And I’m getting 660 lux (about 11.8 lumens) with the Sofirn battery.

So I’m wondering why that is? Evidently this light is not current regulated? I guess I can be OK with it as long as I get proportionally longer run time with the 50E compared to the Sofirn battery.

Lordy lord lord, the reviews at Ali are sooooo helpful.

“If you compare with the batteries of samsung or lji of this format, then the elastic at these batteries less longer warms the speculated ”

Just what I needed to know.

I have C8F in transit. Due to probably overrated “40A continuous” Sofirn 21700 cells I ordered Shockli 21700 4550mAh (purple). Should do 22A continuous and 30A pulse. For testing purposes I also went with one LiitoKala 4000mAh. Looking forward to do some measurements.

To be honest 21700 cells I dont like ordering at all, hate to play the “whats under the wrapper” game. Most of the OEM ones have rather pricey shipping for me.

I don’t know if it is to late of a post but I ordered 2 samsung 40t batts right after ordering a sofirn C8G

At unregulated levels the driver uses PWM to modulate the output so it makes sense. When the leds are on they are at full power so they are brighter with a high current cell.

Have 2 Sofirn C8F. One with the XPL, and the LH351D 90 CRI. I use LG M50 and Samsung 40T.

C8F - XPL
The M50 5000mAh gets a lot of run time, apprx 2600lm at start up - 2200lm at 30s.
The 40T 4000mAh gets less total run time, apprx 2800lm at start up - 2300lm at 30s,

Using TA Lumen Tube.

Haven’t ran tests on the LH351D 90 CRI version as I had just gotten it and haven’t charged full 21700 cells yet.

Between 2600-2800 of the M50 and 40T its not really noticeable to me, so for longer run times the 50T is fine, with 1000mAh more capacity and run time. On turbo it was hot enough to singe my fleece pants very quickly.

OK. Makes sense. Thanks for posting.

Your C8F finally arrived? How is it? Mine finally got to the US on the 15th but unfortunately I’m living out of town due to current events so I won’t be there when it arrives. How is the beam compared to the original XPL-HD version?

The beam has a tighter hotspot, although the spill pattern and extent looks to be similar from 5-6 ft away. Tint is definitely warmer, but within 6 ft you will still see artifacts of the reflector and a halo ring around the spill area. Less noticeable than the XPL version. The artifact seems to be the result of the shallow edges of the reflector and possibly the anti-reflective coating of the lens.

I do like the Higher CRI of the new one. I’ll have to use it a bit more, but its hard to tell a difference other than tint if they aren’t next to each other.