Sofirn sent me their new 5000mAh 21700 cell for testing. I used the West Mountain Radio CBA IV Pro.
This is a rewrapped Lishen LR2170SD
Specs I was given
Diameter: 21,7mm ± 0,2mm
Length: 70,9mm ± 0,2mm
Weight: 72g ± 4g
Nominal capacity: 5000mAh at 0.2C discharge current
Minimum voltage: 2.50V
Maximum voltage: 4.20V ± 0.03V
Standard charge current: 0.2C (1A)
Maximum charge current: 0.7C (3.5mA)
Maximum discharge current: 2C (9.6A)
Initial internal impedance: ≤ 30mΩ
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Slightly risen allowing it to be used in series
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Capacity test at 1A (0.2C) tested 4,975 mAh from 4.20v down to 2.50v
5A = 4,837 mAh
10A = 4,781 mAh
15A = 4,740 mAh
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Showing the 20A discharge was too much reaching 80°C, which is where I stopped the test.
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Sofirn 21700 5000mAh vs Sofirn 21700 4000mAh at 15A
5000mAh - Black / 4000mAh - Red
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Sofirn 21700 5000mAh vs Samsung INR21700-50E
Sofirn 5A - Solid Black / Samsung 5A - Solid Blue
Sofirn 10A - Dotted Black / Samsung 10A - Dotted Blue
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Conclusion: Very decent performing high capacity 21700 cell that can handle up to 15A.
This battery can also be found in the Wurkkos TS30S and some bundles of the TS30. While this battery is great for lights like SF47T and SP35, it is not the best option for FET/DD lights like TS30 or TS30S taking advantage of high drain cells like a Samsung 30T/40T/50S or Molicel P42A.
I agree with Jacob that it’s a very decent and cheap alternative to Samsung’s 50E/G. Most of Sofirn‘s 21700 4000mAh batteries seem to be a Lishen LS2170SA. There are some with a recessed ring and some without, so there’s some variation in there.
Yes, that was a mistake to be sold with the TS30/TS30S. Here’s a comparison at 20A against the 40T. No idea whether they’ll change it, but I can imagine it’ll ruin reviews if they use that cell, already complaints surfacing of poor performance.
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I will not give up encouraging Sofirn and Wurkkos to reach out for better high drain batteries. My guess is they are somehow bound into a long-term liaison with Lishen and DLG but maybe they are willing to rewrap some Molicels or Samsungs for a moderate price.
Did they change the bundled battery with the TS30S yet? I am looking forward to that light. I have a 30Q 18650 which maybe I can use with a sleeve to compare the performance.
Unlikely. They do not have anything better than Lishen LR2170SD or Sanyo/Panasonic NCR21700A. These cells work greatly up to 10A, maybe even 15A. For the TS-series you need something with more juice like Molicel P42A, Samsung 30T/40T/50S if you want to push it to the limit.
I am not sure if that datasheet is allowed to be made public. It is from Lishen and nowhere to find on the internet (at least I did not find it after long searching :-D ).
