How trustworthy are Sofirn batteries?

Ah, no. That’s not how fission plants fail. But you knew that.

I’ve ordered from Sofirn a number of times by now. I cannot order bare batteries from them (bare batteries not allowed to be shipped to my country), so the Sofirn batteries are always ordered only with the Sofirn flashlights.

I have had several Sofirn 18650s by now. The earliest one was the red one (looks like “UltraFire” wrapping), followed by the black wrapper — the black wrapped Sofirn seems to be the current wrapper for the 18650s, and indicates 3000mAh (I’ve ordered a lower Sofirn flashlight model which came with 2200mAh 18650 though, but that is another subject…)

(these are only about the capacity test, didn’t do much IR testing, but )

Sofirn “3000mAh” 18650 (red wrapper, and black wrapper)
-The earliest Sofirn 3000mAh 18650 (red wrapper, or the black wrapper — these 18650s are likely 6 or more months ago) — when I first tested their capacity with my MC3000 (–0.50A discharge to 2.50v), I only got around 2700+ mAh for all of them. (so these are actually a bit lower than their 3000mAh label)

-But the newer Sofirn 3000mAh 18650 (same black wrapping) from more recent order (around 2 months or so ago) — testing their capacity, I’m consistently getting 3000+ mAh capacity (same –0.50A discharge to 2.50v). (they are now correctly labeled)

Sofirn “2800mAh” blue/black-wrapping protected 18650
-The blue/black-wrapped Sofirn 2800mAh protected 18650 are protected batteries, which trip at around 6 amps.
I only got a few of these (I think they were all from around 6 or so months ago) - their tested capacity were 2700-2800mAh, so they are “correctly” labeled.

Sofirn 900mAh 14500:

- now these seem to have several batches too.

- as mentioned above, some of them (the earlier models, as in 6 months or so ago) are quite short in physical length — they are a bit shorter than Eneloop AA NiMh batteries.

- tested capacity are between 800-900mah

  • the newer batch appears to be a bit longer now (similar size to other common unprotected 14500s, not “a bit shorter” anymore), tested capacity seems to still be around 800-900mAh

I asked Tracy at Sofirn if she could explain the capacity of their 26650 cells. Some are sold as 5000mah and some are sold as 5500mah.

Been a few months. Any more data on the Sofirn 5000/5500 26650? I would imagine a lot of BLFers have a few now. Max amp draw? Don’t see a HKJ test yet.

I have a few but they are for sale with the flashlights so don’t really want to test for maximum discharge current.

I have 21pcs of the new high drain 26650’s that should arrive within a week I’ll be giving a good test.

The Sofirn 14500’s are decent at up to 3A

The Sofirn 26650 High Drain are good for just over 10A. Not sure why Sofirn rates them at 25A for Continuous Discharge Current.

Up to 10A they perform as good as a Samsung 30Q

I didn’t expect 25A for 5000mAh capacity. I’m quite happy with their performance

I’ll update with my tests tomorrow

Turns out the battery wasn’t in my clamp correctly for the 15A test.

I’ll perform a 20A test tomorrow and post results but 15A is looking like it’s close to it’s limit.

The 26650 HD is only 4500mAh, not the stated 5000mAh.

they should stop mis-label the batteries capacity, even if they perform ok there are far better options to get today.

Not when it comes down to getting it bundled with a flashlight for so cheap. This is convenient for the countries that can’t get cells shipped by themselves.

To import 100pcs of 18680’s into New Zealand shipping alone costs $120+ USD, whereas it’s free shipping when in a flashlight. Even 10pcs costs $30 USD

I’ll upload my graph tomorrow.

Sofirn 26650 High Drain is only a 15A cell for max continuous discharge current. 20A was far too high. It could be that the added button top is increasing resistance thus causing higher voltage drop than without it

@PiercingTheDarkness, have you ever heard of Queen Batteries?

https://queenbattery.aliexpress.com/store/1332380

They are 100% legit.

Thanks Blue but I always buy in bulk from Lucky Electronic Store

Very expensive shipping to New Zealand via USPS is the only option available right now. There was a cheaper option until some idiot tried to import a gun.

As you can see on the below graph that 20A is too high

I’m sorry, but I don’t see temperatures anywhere on your graph. Are you saying it exceeded 80°C during the 20 amp test?

There’s too much voltage drop on the 20A to be of much use. Sofirn don’t give a data sheet with a max temp so I didn’t want to risk it. 20A reached 70 degrees.

This test on the Samsung 25R shows that the 30A is too high and it’s similar to the 20A curve of the Sofirn. I’m kind of new to judging discharge curves but it looks too high.

EDIT: I don’t know why I can’t link that page but select and search via google and it’ll come up

I always though maximum discharge rates where based on temperature. Cells tend to vary in max temp with some at 70°C and some at 80°C. If it did not exceed 70, then it might be fine at 20A continous. I'm not familiar enough with discharge curves to know what's considered usable or not usable.

HKJ's links uses spaces which require the advanced post editor to post them.

The above link

Well if that’s the case I’d rate it at 20A continuous.

Thank you for helping with the link, I was confused why it wouldn’t work.

I’ll flick Mooch a message via facebook and ask what he thinks

Let's compare it to a Liitokala Black 5000mah which is okay at 20A continous, but got too hot at 30A continous.

Hmmm, looks pretty hard to compare. 20A of the Sofirn HD does look slightly worse than the 20A on the Liitokala.

It's definitely better than the regular Sofirn 26650 cells, but neither are close to the mighty Golisi 4300.

Edit, here is the discharge curve of the Samsung 25R from the link above. I'm not sure how comparable it is to the Sofirn HD, though.

.

Thanks for that Jason. It gave me a boost to try the 25A test,

20A at 64 degrees
25A at 70

Even though it didn’t hit the 80 degrees temp I don’t think it’s handling the 25A current well at all.

Keep in mind that my CBA has a voltage drop of 0.03V at 20A & 0.04V at 25A so it’s not spot on but works well enough to show performance

Just realized I need to run a capacity test at 0.2C (1A)

Yeah, at 25A you can see it sag and then as it heats up the voltage rises back up. That and the big loss of capacity says 25A continous is not so good. I’m surprised the temperature didn’t go higher.

I know HKJ is on this forum, I wonder what he would think of these discharge curves.

Mooch:

Voltage sag and voltage recovery during a discharge is important to watch for in addition to temperature.

Ultra high capacity cells run tens of degrees C cooler at their ratings versus high performance cells.

Multiple cycles at its rating to look for obvious damage often needs to be done also.

Temp cannot be used on its own to set a rating.

Higher IR cells can show greater dips at the start too, at their rating.