Sofirn SC18 Flashlight Review

The Sofirn SC18 is a low-cost 18650-based flashlight that offers USB-C charging and a nice range of output! It makes a great gift!

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Official Specs and Features

Here’s a link to the Sofirn SC18 flashlight product page.

Versions

There’s only one version of the Sofirn SC18 flashlight but it’s available with or without the 18650 seen in this review.

Price

The Sofirn SC18 flashlight sells for the remarkable price of $14.99 or $16.99 with cell. Buy the cell package! 

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Short Review

I can’t even imagine how they make this light for such a low cost. It’s a nice one, too! The build quality is good and charging works great. A complete package USB-C charging flashlight for under $17 just seems crazy! 

Long Review

The Big Table

Sofirn SC18 Flashlight
Emitter:	Luminus SST-40
Price in USD at publication time:	$14.99
Cell:	1×18650
Runtime Graphs
LVP?
Switch Type:	E-Switch
Quiescent Current (mA):	0.01
On-Board Charging?	Yes
Charge Port Type:	USB-C
Charge Graph
Power off Charge Port	With or without cell or tailcap: one mode (medium)
Claimed Lumens (lm)	1800
Measured Lumens (at 30s)	1453 (80.7% of claim)^
Candela per Lumen	11.2
Claimed Throw (m)	217
Candela (Calculated) in cd (at 30s)	530lux @ 5.366m = 15261cd
Throw (Calculated) (m)	247.1 (113.9% of claim)^
Claimed CCT	–
Measured CCT Range (K)	6300-6600 Kelvin
Item provided for review by:	Sofirn
All my Sofirn reviews!

^ Measurement disclaimer:  I am an amateur flashlight reviewer.  I don’t have $10,000 or even $1,000 worth of testing equipment.  I test output and such in PVC tubes!!  Please consider claims within 10% of what I measure to be perfectly reasonable (accurate, even).

What’s Included

• Sofirn SC18 flashlight
• Sofirn 3000mAh 18650
• Charging cable (USB to USB-C)
• Lanyard
• Spare o-rings (2)
• Manual, etc.

Package and Manual

Build Quality and Disassembly

The build quality is great! This light punches WAY above $15.

Size and Comps

Dimension: 101.5mm (length) × 24.7mm (head diameter)
Weight: 55g (without battery)

If the flashlight will headstand, I’ll show it here (usually the third photo).  If the flashlight will tailstand, I’ll show that here, too (usually the fourth photo).

Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

Also above is the light beside my custom engraved TorchLAB BOSS 35, an 18350 light.  I reviewed the aluminum version of that light in both 35 and 70 formats.

Here’s the Sofirn SC18 flashlight alongside a Wurkkos WK03. You might notice that they have similar design!

Retention and Carry

There’s a friction-fit pocket clip included for carrying the Sofirn SC18 flashlight. 

This is a pretty simple pocket clip but does attach securely.

Clip hug!

Next up for carry is the included lanyard. This lanyard attaches through a hole in the tailcap.

There’s just one hole and this prevents clean tailstanding when the lanyard is in use. 

No magnet or anything else is included.

Power and Runtime

The Sofirn SC18 flashlight operates on a single lithium-ion cell.  I have a package that had a cell included.  It’s a 3000mAh button top and is a completely standard cell.

The cell goes into the light in the “usual way” (which is to say that the positive terminal of the cell goes into the light).  

There’s a little silk-screened logo on the side of the body to help with orientation, too.

Here are a number of runtime tests.

Low voltage protection is observed in all tests.

Charging

The Sofirn SC18 flashlight also has built-in charging, by way of a USB-C port on the head. 

Charging works great and only takes around 2.25 hours to complete.

C to C charging even works great, too! Again, for $15….

Modes and Currents

Mode	Mode Claimed Output (lm)	Claimed Runtime	Measured Lumens	Tailcap Amps
Turbo	1800	2.3h	1453	3.91
High	800	2.6h	700	1.58
Medium	350	6.3h	289	0.66
Low	100	23h	75	0.21
Moon	3	230h	2.9	11.4mA

Pulse Width Modulation

Every mode uses PWM. It’s fairly fast PWM and I can’t say I noticed it during use.

For reference, here’s a baseline shot, with all the room lights off and almost nothing hitting the sensor.  Also, here’s the light with the worst PWM I could find.  I’m adding multiple timescales, so it’ll be easier to compare to the test light.  Unfortunately, the PWM on this light is so bad that it doesn’t even work with my normal scale, with is 50 microseconds (50us).  10ms.  5ms.  2ms.  1ms.  0.5ms.  0.2ms.  In a display faster than 0.2ms or so, the on/off cycle is more than one screen, so it’d just (very incorrectly) look like a flat line.  I wrote more about this Ultrafire WF-602C flashlight and explained a little about PWM too.

User Interface and Operation

The Sofirn SC18 flashlight is controlled by a single e-switch. This is a soft switch and has an indication function in the center.w

Below you can see the switch indicating in green. When the Sofirn SC18 flashlight is turned on, the switch will indicate the approximate battery level for around 5 seconds. Green means “good” and red means “poor” (or “low”). Flashing red means recharge immediately. 

Here’s a UI table!

State	Action	Result
Off	Hold	Moon
Off	Click	On (Mode Memory)
On	Hold	Mode advance (LMH)
Any	Double click	Turbo
Turbo or Strobe	Click	Previous state
Any	Click 3x	Strobe
Off	Click 4x	Lockout
Lockout	Click	Main emitter flashes 2x to indicate lockout
Lockout	Click 4x	Unlock (to mode memory)
Lockout	Hold	Momentary moonlight mode

LED and Beam

Sofirn is using a Luminus SST-40 emitter in the SC18. This emitter is coupled with a TIR, and offers a great beam profile.

LED Color Report (CRI and CCT)

CCT for this Luminus SST-40 is fairly cool at around 6500K.  CRI is low too, at under 70.

Beamshots

These beamshots are always with the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure.

Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)

I keep the test flashlight on the left, and the BLF-348 reference flashlight on the right.

I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!

Conclusion

What I like

• Very low cost!
• USB-C charging
• C to C charging works great
• Very nice beam profile
• Cell included for just $2 extra, still under $17
• Indicating switch

What I don’t like

• Very cool CCT
• Lockout goes to main modes (memory)
• No tailcap magnet

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Notes

• This content originally appeared at zeroair.org.  Please visit there for the best experience!
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