What are some legit sites to get decent deals on AW IMR 18650 batteries?
This is a thread for Sofirn batteries.
Hi,
Does anyone have any comments regarding the Sofirn High Drain 21700 Battery 4800mah 48A cells? Do we know who makes the cell under the wrapper?
Thinking of picking up 6 tomorrow (11.11) if they are any good.
Want to use them in Astrolux EC01, Sofirn C8G and a C8F lights and wondered if they are up to the job of driving these lights to their maximum? If not, can anyone recommend which high-capacity 21700 cells to buy?
Many thanks,
Moley
I know that the 4000mAh 21700 cells are very decent but no idea about the 4800.
Generally high capacity cells can’t handle high current. There’s the Samsung INR21700-50E 5000mAh and it can only run continuous at 9.8A.
For the C8G you might be okay but not the C8F. You ideally need low resistance and the least amount of voltage sag on load for the most lumens.
Thank you for taking the time to reply, Funtastic - especially on a weekend; I appreciate it!
For the lights I mentioned, would I be better off with the original Sofirn 21700 4000mAh then? Or, what about Sony VTC6 with a 21700 adapter sleeve as I have lots of VTC6s? Obviously, the capacity would be way down with the VTC6 but what about sheer lumen output with the Sonys 
Thanks again,
Moley
The 4800mah one is strange one. Some people measure 3700-3800mah, while others measure 4800-5000mah. You can read about it starting here.
BTW, you may not want to drive the C8F to the maximum simply because it builds heat quicker and gives you less turbo runtime. I think you’d be okay using a high capacity battery so as to limit turbo output. If you really want to max it out, try a high drain.
The cells under the wrapper are local chinese brands and usually kept secret.
Probably the highest quality, highest performing cells are the ones from LG, Panasonic/Sanyo, Sony/Murata, Samsung and Molicel.
You’d be better off with the Sofirn 4000mAh 21700 for the Sofirn lights.
The real lumen rating of the Sofirn’s are
C8G - 1700
C8F - 2850 to 2950
The C8F draws up to 10A on Turbo. The EC01 draws up to 15A so I have no idea what the Sofirn 21700 can achieve as no one has reported tests on more demanding lights.
I’d recommend something like the Samsung 40T for best performance of the EC01.
I'm getting an internal resistance reading of 75 mR on a Sofirn button top 18650. That seems pretty high. Is it because it's a button top or because of the cell itself? The cell came with a Sofirn SP31 V2. Thanks in advance.
What are you using for testing the resistance? Which Sofirn battery is it?
I’ve seen button tops in general really mess up charger measuring devices. The results would be all over the place even exceeding the max resistance of the display. I removed the button top and added a solder blob and that fixed it (30Q). Other button tops would be fine and show what they should. So it could be the button top. It depends on how it was attached, the amount of power used and the pulse time to weld it together.
Sorry, I don’t have any Sofirn 18650 button tops.
LittoKala LI 500 Engineer charger/tester. Black 18650 3000 mah button top rechargeable 3.7v that came with a sofirn SP31 V2.
You can’t trust the resistance reading then, most chargers aren’t an accurate measurement.
I have the same charger and can get 125 and others 35 using the same battery.
Button tops also raise the resistance, some more than others. Last year I purchased 120pcs Sofirn 18650’s to find the buttons could easily flick off with a knife. Very poor soldering job. The batteries are almost as good as a Sanyo NCR18650GA with the button removed.
Liitokala Lii-500 Engineer doesn’t show precise mR values (values will change even for other batteries).
However, the button on the button-top does add resistance for such kinds of chargers.
I just orded two samsung 40t batteries I do not trust the battery that they offer the sofirn c8g with.
Why?
I don’t know suppose I just think of them as being a rewrap batt.
Besides I had a better deal ordering two legitimate cells for a little more for what sofin wanted for one battery
They are a rewrapped cell because Sofirn is not a battery manufacturer. This does not mean it’s bad, though. It comes from a chinese battery manufacturer and generally speaking their chemical mixes tend to be slightly not as good as a company like Samsung.
The 40T is a top notch cell, but it’s usually more expensive than a chinese battery. The cheapest I’ve seen the 40T is about $7-$8 each plus shipping. If you paid noticable less than that, I would be suspicious if it’s a real 40T.
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I paid 6.99 a cell on 18650batterystore but with a coupon code it came out to 20 bucks shipped sofirn wants 9.99 for one cell that shyed me away lol
If you get a Sofirn battery bundled with the flashlight I find it’s much cheaper on Ali or their website
That sounds legit.