Help choosing 21700 battery for my Sofirn C8F

I also recently purchased a C8F and wanted a spare battery. I went with the Samsung 50E. I was looking at post #36 in this thread:

All three of those batteries make good choices in my opinion but the Samsung 30T and Sofirn battery will give a little higher output current due to lower battery resistance. That’s really only a concern if wanting to use the max output for any length of time.

For me I wanted a little more capacity and will only use the max output on occasion so I don’t care if I have slightly diminished output. (I probably won’t notice the difference anyhow).

Also the charger that Sofirn provides works but I wanted something better. My choice was the Miboxer C4 Upgrade. The Miboxer C2-4000 would fit a 21700 also.

This link has Samsung 50E for $6.99 Samsung 50E 21700 5000mAh 9.8A Battery

the 50E battery might struggle a little in the Amperage category running on high for extended periods. I run the Sofirn 4000 mAh battery with great results! I am awaiting delivery of the Vapecell 4500 mAh cell which I have high hopes for. 20A continuous discharge w/4500 mAh for a bargain is quite good.

Do we know which cell Sofirn is using in their batteries?

As far as spare cells, the Samsung 40T might be the best all-around. It will easily handle the current demands of the C8F, while having 33% more runtime than a 30T. The 5000 mAh cells might work, but they might be getting into the upper ranges of their current ratings.

The Sofirn cell is likely a 40T but thats not confirmed. They can be had for around $10 a pair through Sofirn.

It’s not a Samsung 30T.

It’s Lishen 4000mAh 15A.

Yeah, I just bought the kits and use the come-with cells. They work just fine. No complaints.

I got the kit too & am pleased with the Sofirn also.

Using the Samsung 50E you’ll get a bit more run time but a little less output on Turbo.

Using the Samsung 30T you’ll get a bit less run time but a little more output on Turbo.

The Sofirn battery, as Lightbringer said…… “works just fine”. :+1:

Delta_V mentioned the Samsung 40T, I don’t have one of those; but as he said….it would be a good one. On par with the Samsung 30T, but 33% more runtime.

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.

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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.