How trustworthy are Sofirn batteries?

Batteries and Chargers Rechargeable Batteries
68

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.

69

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

70

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

71

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.

72

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

73

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

74

@PiercingTheDarkness, have you ever heard of Queen Batteries?

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

They are 100% legit.

75

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

76

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?

77

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

78

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

79

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

80

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.

.

81

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

82

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

83

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.

84

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.

85

I have noticed that Mooch and HKJ don’t always agree on the Continous Discharge Rate of the same cell so it makes sense that it is somewhat subjective.

I think I would say the Sofirn HD cell is not good for 25A continous due to it’s big loss of capacity and the dip and recover in voltage.

Maybe 20A CDR is more accurate, but still not quite as good as the Liitokala black or cyan 5000mah (which is 20A CDR).

It’s definitely better than the Sofirn non-HD battery, though. I don’t think anyone has done discharge tests on it like above, but it’s reduced lumens tells me they are not high current at all.

86

I do have a few of the regular Sofirn 26650’s 5500mAh that I’ll test. It’ll be interesting to see the difference.

Ran a capacity test at 0.2C which would be 4800mAh if taken to 2.5v. I stopped discharging lower than 2.8v due to damaging some cells.

87

I wonder if I should start my own thread and list results for each