So what do others think of the Sofirn C01?

zeroair review (2019-01-18)

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I love these little lights. I wish I had bought more (and probably will). These are fantastic to give to a child for nighttime reading, or reading/navigating inside a tent or the like. I completely support you buying at least one of each!! (I don’t even get anything from you buying them!). I’m pleased to have both, and to be able to see the different Yuji tint in person.

djozz on BLF (2018-11-11)

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The output is low and the beam is flood, this light has no punch whatsoever. I kept it in my pocket for weeks together with an E2L triple shorty EDC (also 3000K extreme CRI but 1000+ lumen at max) and in no circumstance that I needed some light for a moment I decided to pick the C01.
But the C01 has already been a nightstand light for my son when we stayed in a hotel (he’s afraid for total dark), doubling as his donald duck reading light in the morning when I was still asleep. For the nightstand duty the diffuser of the Lumintop Worm worked quite perfectly (btw, Barry will try to source a suitable diffuser for the C01 for selling separately). I check the mailbox with the C01 as well. And there’s always the people who want a light that always works when everything else fails, the C01 may prove to be that light over time. At least Sofirn has tried to copy that feature from the Fenix E01. The 95CRI may not be needed for this function but it does not hurt either . I can confirm that the 5 to 7 lumen flood of the C01 will sufficienty light your path in the woods when it is totally dark (it will not spot the bear in the distance ).

parametrek on /r/flashlight (2018-11-27)

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I’m still surprised that a manufacturer listened to and acted promptly on community requests.

slowtechstef on BLF (2018-11-27)

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Sofirn was perfectly right to label the C01 “New BLF Sepcial light”.
This is no spelling mistake but an acronym:
Safe&simple, Endless-runtime, Pocketable, Commemorative clone, high-crI, A-class reliability, Low-lumen.

Henk4U2 on BLF (2018-11-30)

Quote:

Ordered nov. 10th, arrived nov. 26th, so that was pretty fast!
First impression: very well manufactured, especially for that price.
Closer look: petite, but certainly not feeling as fragile as other AAA lights.
And of course quality in the details, such as the noir/djozz-tail.
Have not (yet) tried the clip, but it sure does not feel flimsy.

Specifications (partly tongue-in-cheek) 

User Manual

• download link

Model:

• Sofirn C01

Light source:

• 1 Yuji 5 mm through hole LED (YJ-BC-F5-G01) (Datasheet)
• 60 degrees LED for floody beam

LED life:

• unbreakable bulb (encapsulant material epoxy resin)
• over 100.000 hours on high setting
• bulb never needs replacing

CCT (color temperature):

• 3200K
• 5600K
• 4400K when combining 3200K and 5600K models
 

CRI (color rendering):

• Ra > 93
• R9 > 60
• superior color rendering
• highest CRI values in a traditional 5mm LED form factor

Driver:

• 25 mA current at LED in order not to decrease LED lifetime by overdriving it
• graceful degradation with empty battery, no sudden unexpected darkness
• approximately 60 mA current at battery when it is full
• no PWM; no visible flickering
• no parasitic drain when flashlight is off
• driver board potted with thermal epoxy for increased resilience and waterproofness
• joule thief / battery vampire circuit will suck every last Joule out of a battery 

Power source:

• single 1.5 Volt AAA sized cell
• alkaline primary (LR03)
• zinc-carbon, zinc chloride primary (R03)
• lithium-iron-disulfide (LiFeS2) primary (FR03)
• nickel-metal hydride (NiMH) rechargeable (low self discharge version such as Eneloop recommended) (KR03)
• nickel-cadmium (NiCd) rechargeable (sale banned in European Union)
 (HR03)
• AAAA sized or cylindrical cells from alkaline 9 Volt (6LR61) batteries with do-it-yourself aluminum foil piece adapter
• CAUTION: do NOT use 10440 Li-Ion (3.7 Volt) or 10440 LiFePO4 (3.2 Volt) cells; they will destroy the driver and LED of your flashlight
  

Battery-flashlight combination shelf life:

• 20 years with 95 percent of original capacity (Energizer Lithium LiFeS2 AAA primaries)
• 10 years with 70 percent of original capacity (Eneloop NiMH BK-4MCC A/E AAA rechargeables)
• CAUTION: do NOT store alkaline cells in your flashlight; they will start leaking and destroy your flashlight

Runtime with full AAA alkaline cell:

• low (3200K 6 lumens / 5600K 8 lumens): 20 hours (battery voltage > 1.0 Volt)
• moonlight low (<1 lumen): 13+ hours  (battery voltage < 1.0 Volt
)
• desired output setting can be selected by switching between full or empty battery
• runtime depends on temperature; lower temperature means lower runtime

User interface:

• twist head to left for on while holding battery tube
• twist head to right for off while holding battery tube

Waterproofness:

• IPX8 at 2 meter

Operation temperature range:

• depends on battery chemistry
• lithium primaries are rated for -40 to +60 degrees Celcius

Weight flashlight:

• 13 g (0.21oz) without battery

Weight battery:

• alkaline AAA primary: 11.5g (0.41oz)
• lithium AAA primary: 7.6g (0.27oz)
• NiMH AAA rechargeable: 14-15g (0.49-0.53oz)
• alkaline AAAA primary: 6.5g (0.23oz)


Dimensions:

• 71.1mm (length) by 14.5mm (head diameter)

Material:

• T6061 aluminium

Color:

• black
• blue (limited edition)
• red (limited edition)


Options:

• center-hanging split ring (included)
• reversable pocket clip for use as hat light (included)
• user-installable tritium vial (diameter 1.5mm; length 6mm; available from e.g. mixglo.com, banggood.com, ebay, fishing supply stores)
• user-installable magnet (diameter 5mm; height 3mm; N52 is highest magnetic strength; available from e.g. Convoy store at AliExpress; supermagnete.de; fasttech.com; banggood.com)
• user-installable diffuser (create DIY-cap from small lip balm) or buy one from Sofirn.

CAUTION 

• The areas where the PCB comes in contact with the body tube are small, they might need some cleaning now and then. There might be a potential issue where after thousands of on/off cycles the areas get worn out; djozz developed "a fix while it ain’t broken".
• The Sofirn C01 is a flashlight with a potted driver, that means it is NOT mod-friendly; trying to open up its head might destroy the driver.
• The Sofirn C01 has no low voltage protection by design; remove rechargeable NiMH cell when flashlight starts to dim to moonlight level if you want to prevent accelerated ageing of the NiMH cell.
• The Sofirn C01 is not tested and not certified for use as intrinsically safe light.
• The included pocket clip is made from metal that is painted black, some people have reported the black paint to come off.
• Remove the included pocket clip at the point where it is attached to the flashlight, otherwise you might break it.
• .

djozz wrote:

I’d buy one, nice!, but I will admire you if you get Fenix to do special editions on request! (never heard of that)

It is always good to have dreams.

In case Fenix would not be interested in such an innovative special edition, then perhaps another good candidate manufacturer for high CRI 5mm Yuji twisty AAA could perhaps be Reylight?

I think the combination of high CRI, high reliablity due to fully potted electronics, high runtime (15+ hours on single AAA battery) at a low price point (sweet point >15 USD) is currently not available commercially. Therefore such a light could be an interesting commercial niche.
Also because it could be attractive to both “flashaholics” as well as “muggles”. Key to selling however, would be explaining to people the benefits of high CRI. And why a potted flashlight at this price point is so special.

I can already imagine a video with torture tests

Parametrek wrote:

Normally I would be interested but I already have a Yuji GIU and imho a Yuji E01 would not be an improvement.

I highly recommend the Gerber Infinity Ultra as a Yuji host. Easy to mod with low temperature white threadlocker and only the inductor coil is potted. Lots of o-rings. Decent clip for hatlight use. Can use AA or AAA batteries. The “tail switch” is great. Kind of tailstands

Thanks for your suggestion for the Gerber Infinity Ultra (AA/AAA) as a “cockroach” light with high CRI emitter.
That one is certainly an attractive light as well

I think what is important here is to keep in mind the general design pattern of a high CRI cockroach light, a niche that is currently not addressed in the flashlight market:

1. high CRI (Yuji 5 mm led)
2. high reliability (twisty design, potted electronics, single mode, robust 5mm led that does not need a lens)
3. low-price (simple design, cheap 5 mm LED)
4. long runtime on readily available cells (AAA / AA alkaline cells) with battery vampire driver

Hopefully Fenix is interested in making a high CRI cockroach flashlight, because they only need to swap in the Yuji led in their E01 and all would be great, because they already have a good driver and reliable potting.

However if they are not interested, than I would be more than happy if another manufacturer (Lumintop?, Reylight?, Thorfire/Sofirn?) produces a Fenix E01 clone as long as they put in the Yuji 5 mm led, and fully encapsulate the driver with a good quality potting material.

djozz wrote:

A website thing: if you keep the interest list in the second post, every update gets subscribers of this thread a notification email (if notification mails are turned on like I have) and a click on the link in the mail gets you to the updated list instead of new posts in this thread. If the list is in the first post this does not happen, updates of the first post do not generate notification mails.

thanks I move the interest list to the first post

So to explain what this initiative is about:

Basically I and other flashlight lovers as well want a high CRI flashlight that has the reliability of a HDS but only costs 15 USD.
Currently this particular combination of flashlight parameters is not commercially available.
A really simple solution to this unaddressed need is modding a Fenix E01 (high reliability) with a Yuji 5mm led (high CRI).

However instead of hacking the E01 flashlight itself, with the leverage of the BLF (and possibly other flashlight communities such as CPF or TLF) collectively we can hack Fenix the company, to do the modding work for us.

Let’s call this process meta-hacking

Ozythemandias wrote:

> Wants a cockroach light
> Suggests Reylight or Thorfire/Sofrin

. . . . .

If we tell them how to built it, they can do it.
Then on the definition of cockroach light:
- cheap
- reliable (potted electronics)
- long runtime on common alkaline cells (battery vampire circuit)
- simple twisty design

Any Chinese flashlight manufacturer can built such a flashlight by copying the Fenix E01 design and put in Yuji LED. Given they are willing to do so. Let us provide them the motivation by making clear there are buyers.

bmengineer wrote:

I’m no expert, but I think potting shitty electronics might still result in an unreliable light

Absolutely true: garbage in, garbage out

That is why Fenix is the number 1 choice for this project as they have a track record for building reliable stuff.

If that option does not work out, I am sure there is enough expertise in the international flashlight enthusiast comminity to design a driver that is at least as reliable as the one in the Fenix E01. If not by just simply cloning it.

I am no electrical engineer, perhaps someone could chime in to explain how to build uber-reliable (flashlight) driver boards. I am certain though that potting by encapsulation makes circuits able to better withstand environmental stress such as vibration, temperature shock, moist.