How trustworthy are Sofirn batteries?

From Convoy AliExpress store for the new M21A

I can confirm the Sofirn 21700 has no OEM wrap underneath

Here’s my test of the Sofirn 18650 3000mAh

Here’s the Sofirn vs the NCR18650GA

I purchased a bulk lot of 100pcs and the above test is from that lot. I have another cell the same from 1 year ago and it performed much much worse. They’ve changed cells within the last 6 –8 months

Current cell - 65.8mm with white OEM wrap
Old cell - 66.3mm with pink OEM wrap

Measurements are taken excluding the button top

Who’s qoute is this? It is completely false.

Simon from Convoy

Do you know where he said this and if someone has corrected him yet?

Go onto his AliExpress store and look at the description on his new 21700 models

Okay, I think he was talking about battery diameter and that double wrapped cells won’t fit in his particular flashlights.

He is not saying anything about their quality, etc… We know Vapcell, Sofirn and Lishen 21700 cells are really good quality.

I don’t know what cells have single wrappers and what cells have double wrappers so I can’t comment on that part.

You might want to shrink your pictures like this, they are really huge.

Yours were larger lol

I’ve reduced the size

In post 80 I linked some pictures directly from HKJ’s website. I had to use the advanced post editor and have no idea how to make them show up smaller. Sorry.

How to use the advanced post editor to insert images scaled to fit.-

General tab, Dimensions: input 100% in the width (x-axis) field. This prevents aspect ratio issues.

Advanced tab, Style: input max-width: n%, where n is the amount of relative width to the available thread post box width.

As an example the following emoji is set at 25% max-width, so it should appear huge and pixelated:

:-)

On my Advanced tab is says Dimensions: _ x_ - like width times height. I put 100% in the first box, nothing in the second box and unchecked the “constrain preportions”. It worked! I would not have thought to try that. Thanks.

Sofirn 26650 5500mAh - Red Line
Sofirn 26650 5000mAh HD - Black Line

5A - CBA 0.01v drop
10A - CBA 0.02v drop
15A - CBA 0.03v drop
20A - CBA 0.04v drop

I’m surprised how close they perform. You’d think they were the same cell minus some capacity. The button top of the HD cell would be adding resistance so I wonder if that’s it’s limitation.

Well, you can certainly set the proportional size in General tab -> Dimensions. In doing so, the image will fill that much screen width in any case. As an example, this ROFL emoji at 30%:

What I said concerning the Advanced tab -> Style, just made up my mind better. The max-width property can be used to limit the span of a low resolution image to avoid it becoming too large in big screens and looking awful.

As an example, the following gif is set with 672 × 420 pixels of resolution (336 × 210 actual) and max-width: 100% property. Thus it should fill the whole forum box or close in small devices, but remain no larger than 672 × 420 in larger screens:

As I see there's a problem with the aspect ratio when I rotate my smartphone screen, it does reduce its max-width but not the height. This is undesirable.

I was told of this property by a zak.wilson on a related thread, but it really does not work as intended without a max-height adjustment.

:-)

This is odd because Sofirn measured a big difference in output with the SP70. Their regular 26650 battery made 5500 lumen and the HD battery made 7000 lumen.

If you cannot measure or see such difference then it doesn't exists. At least for :-) you, which already is enough.

Those cells are overrated. You know you can get better ones somewhere else and cheap, too. Maybe they buy in bulk from some lesser name provider and either they already get the cells binned and label wrapped accordingly (5000mAh for the lower performing, lower graded cells and 5500mAh for the high ones) or they do in house binning and rewrapping (could be, but don't think so).

≈200mAh of capacity difference for ≈4500mAh cells is less than 5%. The discharge curves' shape matches perfectly. Same OEM cell, just different grade.

I’m not sure what you mean here. None of the big 4 companies make 26650 so they all come from “lesser” providers. Are you dividing these “lesser” providers into two groups, “lesser” and “more lesser”?

Getting “better” ones is no so easy for people in certain countries which is why Sofirn sourced the HD cells in the first place.

As far as choosing between “lesser” and “more lesser” I’m not sure. The test above on the Sofirn 5500mah makes it look quite good (like a high drain 4500mah cell). I was told by Sofirn as well as other users that the non-HD 5000 and 5500 were not capable of high amp draws on FET driven lights. Maybe they recently upgraded all their 26650 cells?

Funtastic, have you measured any Of the “better” 26650 cells like Liitokala cyan or black or maybe the Keeppower 6000/Shockli 5500? (I like the Aspire 4300) I’m curious how it would compare to the Sofirn cells on your test equipment. A real apples to apples comparison.

@JasonWW, the reason Simon says not to use Lishen 21700s(PLB 21700s 4500mAh), is that they are thicker than standard 21700 cells, and so, they don’t fit in the thin Convoy tubes.

Unfortunately I haven’t got any other 26650’s that would compare.

I compared my 30Q 10A curve to Mooch’s and it’s exactly the same.

These are my own observations of a few Sofirn batteries:

Sofirn "5500mAh" 26650:
- there are at least 2 types (bought them bundled with Sofirn flashlights, at different times).
- their wrapping are similar, but the top look slightly different (will upload pictures next time)
- I used SkyRC MC3000 to charge to 4.20v, then run a discharge at 1.0A discharge current, down to 2.50v cut-off voltage:

- 1) Sofirn 26650 with a somewhat "raised flat-top" has these result:
- around 50mOhms (MC3000 DC IR reading), and capacity test yields around 5300-5400mAh capacity (MC3000 1A discharge current from 4.20v to 2.50v)
- using the YR1030 battery resistance tester will give around 42mOhms AC IR
- testing on some high-drain flashlights and measuring the tailcap current, gives lower current than many of my various 26650 cells, indicating this is like a lower-drain battery

- 2) Sofirn 26650 with a more "flat" flat-top has these test result:
- around 30mOhms (MC3000 DC IR reading), and capacity test gets around 5000mAh capacity (MC3000 1A discharge current from 4.20v to 2.50v)
- using YR1030 battery resistance tester will give around 14mOhms AC IR (very good - better than many of my various 26650 cells, indicating this seems to be a high-drain cell, maybe not as high-drain as the Golisi or iJoy 26650, but quite good, possibily matching or better than the Lii-50A 26650)
- testing on some high-drain flashlights and measuring the tailcap current, gives higher or similar current reading compared to my other 26650 cells

- I failed to note which of the Sofirn "5500mAh" 26650 are from earlier batch or later batch, because I got them both fairly recently (like a few months ago, and I only did more in-depth comparison capacity test recently)

(the one I refer to as "raised flat-top" 26650 is the right-most 26650.

(the one I refer to as "flatter flat-top" 26650 is the second from the right 26650.

(the left-most 26650 is the so-called Sofirn HD 26650 -- I haven't done much testing on it yet)

(the second-from the left 26650 is another Sofirn 26650, also similar low IR as the "flatter flat-top" Sofirn 26650; I haven't finished testing it yet)


~~~~~~~~~

Sofirn 3000mAh button-top 18650:
- again, there are at least 2 types of this 18650 (possibly more); again I can only purchase Sofirn batteries when bundled with Sofirn flashlights
- I think the earlier batch has the lower capacity test reading, while the later batch gives a higher capacity test reading.

- physically, the 2 types look the practically exactly the same, I only noted they had to be different due to the YR1030 AC IR reading being different -- the YR1030 battery resistance tester generally gives very consistent readings

(button-top have some contact resistance, and my MC3000 gives inconsistent reading, so I have to keep on reseating them a few times and get the lower relatively consistent IR reading for my "test")

1) "older" Sofirn button-top "3000mAh" 18650:
- YR1030 battery resistance tester gives AC IR reading of around 24mOhms AC IR
- MC3000 DC IR reading is around 50+ to 70+ mOhms (again button-top now has some "issues" with my MC3000 slider...)
- capacity test (0.50A discharge current from 4.20v to 2.50v), gets around 2700-2800mAh capacity reading
- I wonder what actual battery is used (maybe it's the "pink" battery mentioned elsewhere in this thread?)

2) "newer" Sofirn button-top "3000mAh" 18650:
- using YR1030 battery resistance test, the readings are around 31-32mOhms AC IR

- MC3000 DC IR reading is around 70-90mOhms DC IR (again, button-top batteries give somewhat erratic reading on my heavily used MC3000, since the slider spring on my MC3000 is quite loose now...)

- capacity test (using 0.50A discharge current, from 4.20v to 2.50v), I get capacity test reading of around 3000-3100mAh capacity.

- though I didn't try tearing off the wrapper yet, I believe this is quite similar to the white DLG(H) 3200mAh battery (I have gotten the flat-top white DLG(H) 3200mAh 18650 from a local source and these have very closely related AC IR reading and capacity test reading), as these also give similar capacity test reading