Test/review of Sofirn 18350 850mAh (Blue)

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HKJ's picture
Last seen: 2 weeks 1 day ago
Joined: 05/24/2011 - 12:23
Posts: 7447
Location: Copenhagen, Denmark
Test/review of Sofirn 18350 850mAh (Blue)

Sofirn 18350 850mAh (Blue)
Official specifications:

  • Voltage: 3.7V
  • Nominal Capacity: 850mAh
  • Minimum Capacity: 800mAh
  • Charge voltage: 4.2V +/0.03V
  • Discharge cut-off voltage: 2.75V
  • Standard charge current: 0.2C
  • Standard discharge current: 0.2C
  • Rapid charge current: 0.5C
  • Rapid discharge current: 0.5C
  • Maximum discharge current: 5C
  • Internal resistance:

This 18350 from Sofirn is from the old generation, i.e. moderate current and not top capacity.
DSC_3635 DSC_3636
The curves tracks fairly well and shows that the battery has very good capacity for the old generation, but is rather bad at much current. It is best used at or below 1A, maybe 2A.
The cells has fairly good capacity, but is best for devices with a limited current consumption.
Notes and links
The batteries was supplied by a reader 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 other LiIon batteries
Table with all tested LiIon batteries

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Last seen: 12 hours 9 min ago
Joined: 08/04/2017 - 23:58
Posts: 2619
Location: Manila, Philippines

Thanks for the review.

Hope more Sofirn batteries can be reviewed in the future… although in my limited experience, Sofirn uses different internal batteries (my educated guess) for their 21700 (at least 2 or 3 different types) and also the 26650 (also at least 3 different types), based on my AC IR resistance measurement (using YR1030 resistance tester to measure AC IR) , capacity test and also the physical body design (minor) differences..

Henk4U2's picture
Last seen: 3 hours 51 min ago
Joined: 02/13/2014 - 17:52
Posts: 4178
Location: The heart of the Netherlands (GMT+1)

Thank you for your review HKJ.

Would not hesitate to buy lights from Sofirn.
But when it comes to cells or batteries I stick to the major brands. Preferably tested by you.
Sofirn batteries are a bit of a gamble, depending on the cell’s they can lay their hands on att.

EDIT: The last line was not intended to critisize Sofirn.
I was referring in general to batteries sold by manufacturers focussed on making flashlights.
Who buy and rewrap batteries from several third party companies they don’t (and can’t) control.
Those batteries may be excellent, mediocre or bad. I don’t know, chances are they don’t know either.

You are a flashaholic if you are forced to come out of the closet, to make room for more flashlights.

Lux-Perpetua's picture
Last seen: 1 month 1 week ago
Joined: 03/01/2018 - 04:39
Posts: 3196

I am not sure if this has come to anyone's attention yet. But Sofirn has started selling their SP33 V3 with 26650 batteries from PLB. PLB is known for their popular and top-rated PLB-55A cell. Maybe it's worth testing their new PLB battery, too. Here is some information I gathered from their website.




For comparison: Shockli IMR 26650 5.500mAh (= PLB55-A cell)

Picture taken from https://lygte-info.dk/review/batteries2012/Common26650comparator.php

Funtastic's picture
Last seen: 16 hours 42 min ago
Joined: 06/26/2014 - 02:14
Posts: 2218
Location: New Zealand
Lux-Perpetua wrote:

I am not sure if this has come to anyone’s attention yet. But Sofirn has started selling their SP33 V3 with 26650 batteries from PLB. PLB is known for their popular and top-rated PLB-55A cell. Maybe it’s worth testing their new PLB battery, too.

That first graph is mine. Using 2x Sofirn 5000mAh 26650’s in the Sofirn TK70 (bypassed springs) I got 6500 lumens. Using these PLB cells I got 8000 lumens. They certainly seem to be very decent.

The 20A curve is 0.05v lower than it should be due to the resistance of my setup

Texas Ace Lumen Tube calibrated with maukka lights

New Zealand store – https://www.piercingthedarkness.co.nz (NZ customers only)

YouTube channel – https://www.youtube.com/channel/UCIUWi2vYp4CWrRkOJM70t_w/videos (Demos for my customers, and reviews)