Sofirn SR20 Mini EDC Torch Review
Sofirn SR20 Mini#
- Specifications
- Introduction
- Torch in use
- Build quality
- LED, bezel, lens, reflector and beam
- Size and comparison
- User interface
- Batteries and charging
- Performance
- Beamshots
- Thermal Images
- Conclusion
- Price
- Product page
Specifications#
| Brand/model | Sofirn SR20 Mini |
|---|---|
| LED | 3* CSP2323 White, 3* HFL1-R Red |
| Maximum lumens | 1,200 lm |
| Maximum beam intensity | 5,050 cd |
| Maximum throw | 142 m |
| Battery | 1* 18350 Li-ion |
| Onboard charging | Yes (USB-C) |
| Material | Aluminium |
| Modes | 5 |
| Blinkies | White Strobe, Red Flash |
| Reflector | TIR |
| Waterproof | IPX8 |
| Review date | May 2025 |
Introduction#
The Sofirn SR20 Mini is an 18350-sized EDC torch with three white and three red emitters. It has built-in USB-C charging, a powerful magnet in the tailcap and it comes with a lanyard.
Despite being shaped like a pocket thrower, the Sofirn SR20 Mini has a practical white beam due to the triple TIR optic where helps blend the light from the three white emitters into one spotlight. The red emitters produce a very floody beam.
Sofirn sent this torch for review. I have not been paid for this review nor have I held back my opinions of this torch.
Packaging#
The Sofirn SR20 Mini comes in a white box with a magnetic lid. The outer sheath has an image of the torch on the front and details about the torch on the back.
The following was included in the box:
- Sofirn SR20 Mini
- Sofirn 18350 1100mAh cell
- Lanyard
- Two spare o-rings
- USB-A to USB-C cable
- User manual
User Manual#
Torch in use#
The Sofirn SR20 Mini is tiny! It fits comfortably in my hand between the index and ring finger. It is a bit too short to reach my pinky finger when I try to grip it.
There is a side switch to control both the white and red emitters.
The torch can tailstand or headstand.
I like to use the lanyard when carrying the Sofirn SR20 Mini.
Build quality#
The Sofirn SR20 Mini has a matte black anodised finish. There are no sharp edges.
The bezel is smooth.
There is plenty of grip on the tube and the tailcap.
The threads are anodised so you can lock the torch out by turning the tail slightly.
The tube can be flipped but the orientation of the battery is laser etched on it.
Threads near the head came well lubricated while threads near the tail did not have any lubricant. This is a little odd. Some manufacturers glue the head to the tube rather than encourage people to unscrew a torch by the head.
I prefer to unscrew the tailcap when removing the battery because the magnet in the tailcap is powerful enough to pull the battery out. If you unscrew the head then the battery might get stuck in the tube due to the magnet.
One possible improvement for the tailcap would be to cut the lanyard hole into the side so that the lanyard does not get in the way when tailstanding the torch.
There are springs at both ends to allow a button top or a flat top 18350 cell to work.
I tested reverse polarity protection (RPP) by putting an unprotected battery in backwards (don’t try this at home!). RPP worked as expected.
LED, bezel, lens, reflector and beam#
The Sofirn SR20 Mini three CSP2323 White and three HFL1-R Red emitters behind a TIR optic.
The bezel has been screwed down against the TIR optic with an o-ring between the two.
There is no glass lens to protect the plastic TIR optic from being scratched.
The MCPCB is screwed down against the head.
CCT, CRI, and duv#
I have taken Correlated Colour Temperature (CCT) and Colour Rendering Index (CRI, RA of R1-R8) measurements with the torch positioned one metre away from an Opple Light Master Pro III (G3).
The CCT is around 5750K, the CRI is around 97 and the Delta u, v is positive (green) for the White Light.
The TIR optic blends the three white emitters to produce a throwy beam with a smooth hot spot that blends out into a green corona.
| LED | Mode | CCT (K) | CRI (Ra) | x | y | Duv |
|---|---|---|---|---|---|---|
| White | Low | 5621 | 98.6 | 0.3296 | 0.3482 | 0.0049 |
| White | Medium | 5670 | 96.9 | 0.3283 | 0.3564 | 0.0095 |
| White | High | 5802 | 97.1 | 0.3253 | 0.3509 | 0.0082 |
| White | Turbo | 5909 | 97.4 | 0.3232 | 0.3443 | 0.0059 |
Calculate Duv from CIE 1931 xy coordinates
Dimensions and size comparison#
Dimensions#
I took the following measurements using a digital caliper.
| Measurement | Unit (mm) |
|---|---|
| Length | 80.76 |
| Head diameter | 31.63 |
| Tube diameter | 21.96 |
| Tail diameter | 24.03 |
Weight#
I took the following measurements using a digital scale.
| Weight | Unit (g) |
|---|---|
| Sofirn SR20 Mini | 54.65 |
| Battery | 22.34 |
| Sofirn SR20 Mini with battery | 76.99 |
Size comparison with its competition#
From left to right: Sofirn SR20 Mini, Manker E14 III, Manker Timeback III
From left to right: Sofirn SR20 Mini, Manker E14 III, Manker Timeback III
User interface#
The Sofirn SR20 Mini is controlled by a side switch.
White Light has three modes in the main cycle group: Low, Medium and High; and shortcuts to Moonlight, Turbo and Strobe.
Red Light has four modes in the main cycle group: Low, Medium, High and Turbo; and a shortcut to Flash. Moonlight may be accessed by first going to Moonlight for the White Light by long pressing the button from off and then by clicking the button three times to swap to the Red Light.
Here is the UI diagram from the user manual:
| LED | State | Action | Result |
|---|---|---|---|
| Off | Long press | White Light Moonlight | |
| Off | Click | White Light On (mode memory) | |
| Off | Two clicks | White Light Turbo | |
| Off | Three clicks | White Light Strobe | |
| Off | Four clicks | Lock | |
| Locked | Two clicks | Unlock and White Light On (mode memory) | |
| Locked | Four clicks | Unlock and White Light On (mode memory) | |
| White | On | Long press | Cycle (Low, Medium, High) |
| White | On | Click | Off |
| White | On | Two clicks | Turbo |
| White | Turbo | Two clicks | Strobe |
| White | Turbo | Long press | Low |
| White | Strobe | Two clicks | White Light (mode memory) |
| White | Strobe | Long press | Nothing |
| White | On | Three clicks | Red Light |
| Red | On | Three clicks | White Light |
| Red | On | Long press | Cycle (Low, Medium, High, Turbo) |
| Red | On | Two clicks | Flash |
| Red | Flash | Two clicks | Low |
| Red | Flash | Long press | Nothing |
Both white and red lights cannot be on at the same time.
Mode memory#
Low, Medium and High are memorised for the White Light.
The equivalent mode is selected when changing between White Light and Red Light. E.g. White Moonlight will go to Red Moonlight and White Strobe will go to Red Flash.
Strobe#
Strobe has an alternating frequency.
White Light: Strobe
Red Light: Flash
I measured White Strobe and Red Flash with a Zoyi ZT-701 oscilloscope.
Battery Level Indicator#
The indicator LED under the side switch will display the following for 5 seconds after turning the torch on:
| Colour | Battery level |
|---|---|
| Green | 70% - 100% |
| Red | 30% - 70% |
| Red flashing | 1% - 30% |
Low voltage protection#
The torch has low voltage protection.
I tested low voltage protection by connecting the driver of the torch to a bench power supply and then by lowering the voltage from 4.2V to 0V.
The light turns off at 2.69V.
Pulse Width Modulation#
There is PWM but I did not notice any visible PWM (flickering).
I measured the PWM of the light with a Zoyi ZT-701 oscilloscope.
White Light (Moonlight, Low, Medium, High, Turbo)#
Red Light (Moonlight, Low, Medium, High, Turbo)#
What I like about the UI#
- Direct access to Moonlight (White) from off by holding.
- Direct access to Turbo (White) from off with two clicks.
- Direct access to Strobe (White) from off with three clicks.
- The white and red lights both have the same number of modes (6).
What could be improved#
- Direct access to the red light from off would make this much better for people looking for a red torch to use at night.
Batteries and charging#
Battery#
A button top Sofirn 18350 3.7V Li-ion 1100mAh cell was included inside the torch. It arrived with a voltage of 3.94V.
The cell was isolated with a piece of plastic to prevent accidentally turning the torch on.
I tried the following cells:
| Cell | Top | Compatible? | Comment |
|---|---|---|---|
| KeepPower IMR18350 3.7V Li-ion 1200mAh | Button | Yes | |
| KeepPower IMR18350 3.7V Li-ion 1200mAh | Flat | Yes | |
| Manker 18350 3.7V Li-ion 1100mAh USB-C | Button | No | Too long. |
| Skilhunt BL-111 18350 Li-ion 1100mAh 3.6V | Button | Yes | |
| Sofirn 18350 3.7V Li-ion 1100mAh | Button | Yes | |
| Vapcell F14 18350 3.7V Li-ion 1400mAh (green) | Recessed | Yes | |
| Vapcell M11 V1 18350 3.7V Li-ion 1100mAh (purple) | Flat | Yes | |
| Vapcell M11 V2 18350 3.7V Li-ion 1100mAh (yellow) | Flat | Yes | |
| Wuben ABJ1100C 18350 3.7V Li-ion 1100mAh | Button | Yes |
Charging#
The Sofirn SR20 Mini has built-in USB-C charging.
Power supply: PinePower Desktop USB-C
USB Meter: ChargerLAB Power-Z KM003C
Room temperature: 21 C
The battery took 1 hour 38 minutes to charge from 2.869V to 4.165V at a rate of 5V 1A.
The charging status indicator in the button is red while charging and it turns green when charging is complete.
Power supply compatibility#
I tried the following power supplies with the built-in USB-C charger:
| Power supply | USB Type | Protocol | Does it charge? |
|---|---|---|---|
| Apple 61W Power Adapter | USB-C | PD | Yes |
| Google Pixel Power Adapter | USB-C | PD | Yes |
| PinePower Desktop | USB-C | PD | Yes |
| PinePower Desktop | USB-A | QC | Yes |
| PinePower Desktop | USB-A | Yes |
USB-C to USB-C charging works.
Performance#
Specifications from the manual:
White Light:
| Mode | Moonlight | Low | Medium | High | Turbo | Strobe |
|---|---|---|---|---|---|---|
| Output (lumens) | 1 | 10 | 150 | 500 | 1,200 + 500 | 1,200 |
| Beam Distance (metres) | 3 | 20 | 52 | 96 | 142 | |
| Runtime | 460h | 32h 50min | 4h 30min | 1h 30min | 2min + 1h | 2h |
| Beam Intensity (cd) | 2.8 | 97.5 | 687.5 | 2,325 | 5,050 |
Red Light:
| Mode | Moonlight | Low | Medium | High | Turbo | Flash 0.5 Hz |
|---|---|---|---|---|---|---|
| Output (lumens) | 1 | 3 | 40 | 70 | 150 | 40 |
| Beam Distance (metres) | 3 | 10 | 15 | 19 | 28 | |
| Runtime | 270h | 44h 10min | 4h | 2h 10min | 2h | 8h |
| Beam Intensity (cd) | 1.8 | 25 | 56.3 | 90 | 191.3 |
I tested the torch with the included battery.
Lumen measurements#
I used a bench power supply to measure the current at turn on for most modes. I used a UNI-T UT139C Digital Multimeter to measure the current at turn on for Moonlight and Low modes.
| LED | Mode | Amps at start | Specs | Lumens @turn on | Lumens @30 sec | Lumens @10 min |
|---|---|---|---|---|---|---|
| Red | Moonlight | 15.2 mA | 1 | |||
| Red | Low | 55.7 mA | 3 | |||
| Red | Medium | 0.38 A | 40 | |||
| Red | High | 0.86 A | 70 | |||
| Red | Turbo | 1.68 A | 150 | 155 | 144 | 53 |
| White | Moonlight | 5.9 mA | 1 | |||
| White | Low | 37.5 mA | 10 | 10 | 10 | 9 |
| White | Medium | 0.34 A | 150 | 122 | 121 | 113 |
| White | High | 0.88 A | 500 | 369 | 352 | 321 |
| White | Turbo | 2.85 A | 1,200 + 500 | 1,012 | 933 | 601 |
Turbo (White) did not reach 1,200 lumens when I tested it.
Moonlight (White) was too low for my DIY lumen tube to detect.
I have not measured the lumen ouput of all the red modes (Moonlight, Low, Medium, High).
Standby drain#
I used a UNI-T UT139C Digital Multimeter to measure the standby current.
143 µA
Runtime graphs#
I used my own DIY lumen tube with a TSL2591 sensor and forked bmengineer’s project RuTiTe to record runtimes.
Note: Lumen measurements may be off by 10% with my DIY lumen tube.
The room temperature was approximately 21 C.
White Light#
Red graph#
Runtime#
Here is a summary of the runtime results:
| LED | Mode | User manual | Runtime | Turn off | Final voltage |
|---|---|---|---|---|---|
| White | Turbo | 2min + 1h | 1h 14min 10s | 4h 27min 31s | 2.83 |
| White | High | 1h 30min | 1h 35min 49s | 3h 59min 37s | 2.82 |
| White | Medium | 4h 30min | 4h 56min 56s | 6h+ | 2.75 |
| White | Low | 32h 50min | 10min+ | 10min+ | |
| White | Moonlight | 460h | 10min+ | 10min+ | |
| Red | Turbo | 2h | 1h 54min 24s | 2h 18min 56s | 2.93 |
“Runtime” is the time until the output reduces to 10% of the output at 30 seconds (as per the ANSI/PLATO FL1 2019 Standard).
“Turn off” is the time until my DIY lumen tube no longer detects more than one lumen.
“+” indicates that the light remained on after recording had stopped.
The runtimes are good. They are close to what Sofirn claim.
Sofirn mention that a FET driver is used for White Light while a buck driver is used for Red Light in the user manual.
Throw#
I took lux measurements with a UNI-T UT383BT at 30 seconds.
Moonlight and Low were measured at one metre. Medium, High and Turbo were measured at five metres.
| LED | Mode | Specs (cd) | Specs (m) | Candela measured (cd) | Distance (m) |
|---|---|---|---|---|---|
| White | Moonlight | 2.8 | 3 | 1 | 2 |
| White | Low | 97.5 | 20 | 92 | 19 |
| White | Medium | 687.5 | 52 | 1,050 | 64 |
| White | High | 2,325 | 96 | 3,275 | 114 |
| White | Turbo | 5,050 | 142 | 8,250 | 181 |
Beamshots#
I went to a local park and aimed the Sofirn SR20 Mini at a tree 70 metres away while using Turbo.
Beamshots were taken using a Sony RX100M2 using 3.2", f3.2, ISO 100, 5000K WB.
Sofirn SR20 Mini (White) Turbo#
Olight Warrior Nano (Turbo)#
Wurkkos TS10 (14500) (Turbo)#
I later visited a playground and aimed the Sofirn SR20 Mini at a big apple approximately 2 meters away while using the red emitter.
Red beamshots were taken using a Sony RX100M2 using 0.25 second shutter, f3.2, ISO 800, 5000K WB.
Sofirn SR20 Mini (Red) Turbo#
Wuben G5 (Red)#
Nitecore HA23 UHE (Red) High#
Nitecore NU27 (Red) High#
Thermal Images#
I used a Zoyi ZT-R01 IR Thermography Multimeter to take thermal images of the Sofirn SR20 Mini placed facing up on a silicone mat while using Turbo.
Room temperature: 15 C
| Time (mm:ss) | Max Temperature |
|---|---|
| 00:00 | 17.2 C |
| 01:00 | 26.5 C |
| 02:00 | 34.7 C |
| 03:00 | 40.5 C |
| 04:00 | 41.5 C |
| 05:00 | 42.9 C |
The torch did appear to reach the 55 C thermal limit (see the user manual).
Conclusion#
The Sofirn SR20 Mini is a pretty solid choice for a budget light if you are looking for something 18350-sized with a bit of flood and a bit of throw.
I am impressed with how Sofirn continue to get the basics right (e.g. Low Voltage Protection, Reverse Polarity Protection).
That said, for US$27.99, it could use a glass lens to help protect the TIR optic from scratches.
I like how the White Light and Red Light are treated equally. They both have the same number of modes. It would be even better if it had a shortcut to Moonlight (Red) from off.
The user interface takes a bit of learning. I got used to it after a few months.
The beam distance and runtimes are good.
The lumen ouput was slightly lower than expected for Turbo. It would be even better if Sofirn included a high drain cell so that it could reach 1,200 lumens.
Pros:#
- Small size.
- Good build quality.
- Good runtimes.
- Good beam distance.
- Built-in USB-C charging.
- Heaps of modes for both white and red lights.
Cons:#
- The included battery is ok but a high drain cell would be better.
- Turbo (White) did not reach 1,200 lumens when I tested it.
- No direct access the the red light from off.
- Slightly green beam.
Price#
The Sofirn SR20 Mini is US$27.99 from sofirnlight.com at the time of writing.
Product page#
Sofirn SR20 Mini at amazon.com (affiliate link)
Sofirn SR20 Mini at sofirnlight.com
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