Test/review of Sofirn 21700 5000mAh (Black)

Batteries and Chargers Rechargeable Batteries
1

Sofirn 21700 5000mAh (Black)







Official specifications:

  • Battery Capacity: 5000mAh

  • Battery Voltage: 3.6V



A high capacity 21700 from Sofirn.











The two cells match nicely and have a build in fuse that I blew on both batteries, one at 30A and one at 20A.
















Some test is missing due to the blown fuse in the cells.



Conclusion

The batteries looks like good batteries, but be careful with overloading them, the protection will disable the cell permanently (This is, of course, better than risking a battery explosion).



Notes and links

The batteries was supplied by Sofirn for review.

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries
Graphical comparison to 18650 and other batteries
Table with all tested LiIon batteries
2

Thank you! Tests for batteries which come bundled with flashlights are very useful for the community.

3

Thank you for this! Could you do the same for the 4800 mAh and maybe even for the 4000 mAh 21700 cells?
The Sofirn (rewrapped) cells seem to be good quality and a more affordable alternative to Samsung & co. Especially where I live, li-ion cells are expensive as hell, thus most of my cells are from Sofirn, no matter which size.

4

Thank you for the review, HKJ. I hope Sofirn can send you another pair anytime soon.

The raw cell underneath the shrink is a Lishen LR2170SD. Here are the manufacturerā€™s specs:

Diameter: 21,7mm Ā± 0,2mm

Length: 70,9mm Ā± 0,2mm

Weight: 72g Ā± 4g

Nominal capacity: 5000mAh at 0.2C discharge current

Minimum voltage: 2.50V

Maximum voltage: 4.20V Ā± 0.03V

Standard charge current: 0.2C (1000mA)

Maximum charge current: 0.7C (3500mA)

Maximum discharge current: 2C (10000mA)

Initial internal impedance: ā‰¤ 30mĪ©

Funtastic made a review, too:

5

Thanks for the review. I see Sofirnā€™s latest 5000mAh 21700 battery have a 50A rating on the wrapper instead of 18Wh. Look at the pictures here: https://www.sofirnlight.com/products/2-21700-5000mah-batteries . It shows 18Wh on the flat top cell pics and 50A on the button top ones. That said I just recā€™d a flat top cell with the 50A in the wrapper from them yesterday. I would love to know how high a discharge rate it can handle.

BTW, did you ever test their 4000mAh 21700 cell that the wrapper says can do 40A?
EDIT: I found that review:
https://lygte-info.dk/review/batteries2012/Sofirm%2021700%204000mAh%20(Black)%20UK.html

1 Thank
6

Interesting...

So the 40A cell can handle 20A fine, but not 30A.

Good to know.

It's still a pretty decent cell overall, though.

I'm guessing that if you want a cell that can handle a lot of amps, the MOLICEL/NPE INR-21700-P42A is still one of the best budget choices.