Help choosing 21700 battery for my Sofirn C8F

vs19 · 2019-01-08T16:04:03.000Z

Hi everyone,

I’m new to the game and get a bit overwhelmed by the level of technicality needed to make useful choice.
I just order from Sofirn on Aliexpress the C8F kit.It includes the lamp, a charger and a 21700 battery.
It’s a Sofirn 21700 Battery 4000mah Rechargeable li-ion Battery 40A 3.7V.

I trust them to deliver a decent battery for their flashlight but I saw better?, bigger? battery such as :

- Samsung 48G 21700 4800mAh 4.8A

Samsung 50E 21700 5000mAh 9.8A
LG M50 21700 5000mAh 7.27A
others ?

But can’t figure out which one is suitable for the flashlight, I plan to use their charger,any input on that ?

Any help and some insight will be really appreciated.
Thanks for reading,
Vincent

hiuintahs · 2019-01-08T16:31:26.000Z

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:

Sofirn C8F 21700 Teardown and Review 18650 Flashlights

I got my C8F after 5 weeks of shipping, maybe it got lost, but I have it now so let’s gets started. The driver retaining ring had a very small amount of glue and came loose with a bit of force from snap ring pliers. [image] The driver is 21mm and is composed of 2 boards soldered together. [image] Here’s a closer look at the components. [image] [image] [image] [image] The back of the switch had a little bit of glue holding it in place. I was able to push it out from behind with a little…

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.

texas_shooter · 2019-01-08T18:27:40.000Z

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

wstrachan · 2019-01-08T19:06:24.000Z

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.

Delta_V · 2019-01-08T19:46:27.000Z

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.

wstrachan · 2019-01-08T19:54:10.000Z

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

BlueSwordM · 2019-01-08T20:20:24.000Z

It’s not a Samsung 30T.

It’s Lishen 4000mAh 15A.

Lightbringer · 2019-01-08T22:20:08.000Z

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

teacher · 2019-01-09T05:01:17.000Z

Lightbringer:

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.

Lightbringer · 2019-01-09T05:05:47.000Z

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.

Lightbringer · 2019-01-09T05:08:00.000Z

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

teacher · 2019-01-09T05:08:30.000Z

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

teacher · 2019-01-09T05:12:13.000Z

Lightbringer:

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

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

Lightbringer · 2019-01-09T05:23:03.000Z

Apparently <16bux on 11-11. Hang on…

Ah, here ya go…

11.11 deal Sofirn 21700 4000 40A 2x for $10.42 Free Shipping Ali Express BudgetLightForum Deal Alerts

2x for $10.42, 4x for $16.57 with free shipping. My understanding is that this cell, which is the one they ship with the C8F v2 kit, has good capacity & performance, especially for the price. This is from Sofirn’s separate battery store. Available for another 17hrs at the time I’m posting this. I ordered four. I also decided to give Sofirn’s 900mAh 14500 a try.

11.11 deal Sofirn 21700 4000 40A 2x for $10.42 Free Shipping Ali Express BudgetLightForum Deal Alerts

Kewl, actually 15.57, ’cause there’s a coupon for a buk off if spending 12bux. Got applied automagically (thought it may’ve been for lights only, but it got applied to this, too). So, color me happy… even though I have no idea what I’ll use these in, ’cept the new C8Fs.

vs19 · 2019-01-09T22:22:08.000Z

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.

hiuintahs · 2019-01-09T23:09:09.000Z

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)

RobertB · 2019-01-10T00:54:50.000Z

teacher:

Lightbringer:

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

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

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.

teacher · 2019-01-10T05:55:33.000Z

Lightbringer:

Apparently <16bux on 11-11. Hang on…

Ah, here ya go…

11.11 deal Sofirn 21700 4000 40A 2x for $10.42 Free Shipping Ali Express

11.11 deal Sofirn 21700 4000 40A 2x for $10.42 Free Shipping Ali Express - #4 by Lightbringer

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

Sofirn 21700

RobertB:

teacher:

Lightbringer:

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

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

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 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. Again, thanks anyway for the offer…. :+1:

teacher · 2019-01-10T08:41:09.000Z

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.

XTAR SC1 Li-ion Intelligent Charger

.

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

XTAR USB Wall Adapter - 2.1amp Output

Brainsick67 · 2019-01-10T13:07:21.000Z

BlueSwordM:

It’s not a Samsung 30T.

It’s Lishen 4000mAh 15A.

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.