@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
Thanks for your detailed write up.
If you look on an angle at the 18650 cells you should see what colour the OEM wrap is on the negative end.
I received the 5500mAh cells with the very recent purchase of my Sofirn SP33’s and they have a flat top that only just makes contact in series. I’d guess this would be the 2nd 26650 you tested. I’m yet to do a 1A (0.2C) capacity test as they take awhile to complete.
This thread is about Sofirn.
That’s real mature. Jason’s comment is 100% relevant to this thread
It was a joke for Jason, as he responded that way to my post suggesting exactly those batteries.
You suggested buying those batteries as if someone where asking what battery to buy. This thread is about Sofirn cells specifically.
I’m suggesting a comparison of the Sofirn cells to those other batteries. I want to have a frame of reference. See how they stack up against each other. This will reveal more info about the Sofirn cells.
I just took the wrapping off of 2 2800 MAH Sofirn 18650 batteries and what would lead you to believe is a protection circuit is just an extension. No circuitry at all. They did register 2637 and 2619 mah for the 2 cells. IR was pretty respectful at 23 and 25. Think it was in the 50’s or 60’s with the fake circuit added. Not sure if they are claimed to be that way or not (Protected). Got these out of the headlamp (D25S) I believe. They seem to be a good battery after all. I did leave the button on them. So the IR may actually be lower if it were removed. Not sure though. I wanted to keep it on.
Today I had a 2800 mah Sofirn18650 with protection circuit stop working. It was never used much, just stored in a locked out S2+ in the car. Waiting in the car, I tried to turn it on and nothing. Took it home and peeled off the protection circuit and seems to be fine. Mine did have a real protection circuit on the negative end. It looks very similar to a 30Q but has no markings and a larger positive terminal.
Mine just had a plastic spacer with a metal cap. The cap had a metal strip which leads to the positive end of the battery. Wish I had kept them to show pics. In the end after rewrapping it, seems to be a very good battery. Was it one of the blue and silver versions?
No, it was a black one. Mine just came off the charger and is ok. Did yours have a black plastic spacer then the metal cap on the negative end? The reason I ask is that inside that black plastic spacer was a circuit.
Earlier (as in maybe last year or a bit more than that), Sofirn sometimes bundled 2800mAh protected 18650s instead of their 3000mAh unprotected 18650s.
I have a couple of these Sofirn 2800mAh protected 18650s, and I did get around 2700-2800mAh capacity reading (using MC3000, discharge from 4.20v to 2.50v at 0.50A discharge current). The protection circuit appeared to trip at around 6 Amps. (testing this protected 2800mAh 18650 on the Astrolux S41 with quad-Nichia, will trip/shut-off when advancing the brightness to Turbo mode).
I’m not sure if they changed the 2800mAh since that time though. (I seem to recall they included the protected 2800mAh on the Sofirn SP32A v1, at least during the early batch…)
You can’t really go by looks. It will say on the wrapper if it’s got a protection circuit. If there is no mention, you have to assume it’s not protected.
I’m thinking the added button top on the 26650 HD cells are adding a lot of resistance. I wonder if Sofirn tested the cell before adding the BT.
I’ve just tested a different variant of the Sofirn 26650 and it beats the HD cell at 10A & 15A. I haven’t yet tested higher current
Is there really anything "legit" about a Trustfire battery? The only cells that I trust that aren't LG, Samsung, Sanyo, Sony, or Panasonic are AW IMR 18350 cells and, of course, those too have to be legit, because there are a lot of fakes floating around out there. As a matter of fact, there are more fakes than genuine AWs. My experience with Trustfire has been that they're all crap cells. With lithium cells, I truly believe that you get what you pay for applies...
I’ve had a few Trustfire 14500’s for about 3 years and they still have a genuine capacity of 800mAh. I wouldn’t trust them though
Any brand battery can be faked since it’s basically a wrapper that identifies it. More than just the brand of battery, you also have to buy from trusted sources. Shops that don’t buy fakes and verify that they receive the genuine article.
It’s unfortunate that the Big 5 you mention don’t make 18350, 14500, 26650, etc… This means your forced to buy from a smaller company, but there are still good quality cells out there.
If you look at some common USA battery stores like MTN, Illumn, IMR Battery, Liion Wholesale, you’ll see that none of them carry Trustfire (afaik). About the only exception I can think of is if a particular Trustfire cell is tested and it actually performs pretty good as in it has about the rated capacity, etc… Then that shop might carry it. It probably will never be the best choice in it’s size, though.
Sanyo do have a 14500 which is the UR14500P. I’ve seen a Sony 14500 but can’t recall the name
That is a good start.
You also have to watch out for fake versions. I think there was a Sony 26650 on the market a few years ago, but it was not actually from them.