Hi,
this is my first post and at the same time my first review here. The syntax is a bit odd, but let’s get it on!
FandyFire STL-V2
Overall Rating: ★★★☆☆
Summary:
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Manufacturer: |
FandyFire |
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Model: |
STL-V2 |
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Battery: |
2x18650 (not included, voltage input 3.2-8.4V) |
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Runtime: |
90 minutes at High (manufacturer claim) |
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Switch: |
Tail, Reverse-Clicky |
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Modes: |
One Group, 5 Modes: High, Mid, Low, Strobe, SOS (short memory) |
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Tailstands: |
Yes, but not very stable |
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LED Type: |
3x Cree XM-L T6 (white) |
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LED output: |
3000 lumens (total) |
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LED wiring: |
serial, 1000mA |
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Lens: |
Glass (coated) |
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Size: |
225x55x55 mm (8.9”x2.2”x2.2” |
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Weight: |
~450g with batteries, ~350g without |
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Price: |
$39.93 (free review sample) |
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From: |
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Date Ordered: |
April 30th, 2014, received May 23rd. |
Pros:
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Light output. Insane!
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Sturdy material, hard to scratch
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Adequate heatsink size
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Undervoltage protection in Hi mode
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Good balance
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Good reflector quality
Cons:
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Mediocre quality control
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Noticeable PWM frequency in lower modes
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SOS and Strobe mode
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Some sharp edges, prone to abrasion
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No undervoltage protection in other modes
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Amperage spikes when turned on
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No thermal grease used
Features / Value: ★★★☆☆
Design / Build Quality: ★★☆☆☆
Battery Life: ★★★☆☆
Light Output: ★★★★★
Overview
Due to misdelivery of a rare (?) 3-Mode torch without any strobe or SOS functions, I go into talking with the very nice support of Lightscastle, Victoria. When she couldn’t offer me the unit I initially ordered, I got the opportunity of testing another flashlight for free, if I do some reviewing work on it. I’m glad to help, and while I personally do not need another lumen upgrade at home, I donated this very model to my workgroup in university. In exchange for some testing equipment (namely a larger regulated power supply), which I don’t have at home right now. You know, you scratch my back and I’ll scratch yours.
So, at university we had a giant incandescent light with D cells, absolutely useless for anything. I wanted to keep form factor, 18650 batteries (I have a ton of spares), and as much light output as possible. The FandyFire STL-V2 seemed a very good candidate. If we had to pay for it, I’d chosen a powerful Single-LED one, like the one I bought for myself. But as I was free to choose in a certain price range…go get em.
Shipping and outer appearance
It arrived in a padded envelope, and was packaged in a thin cardboard box with another layer of padding. Well, any postal serviced didn’t pay much attention to it, so the box was pretty much destroyed, but there has to be much more to damage the torch…
(#1 opened envelope)
(#2 unpackaged)
(#3 size comparison)
The triangle ruler is in centimeters, so it is about 22cm long, just as stated on the website. Weight including two NiteCore 3100 mAh batteries is close to 445 grams. Not very portable, but as I said, we have some ugly incandescent beast over here, so not too bad in comparison. Balance is good when holding it in your hands, with center of gravity close to the thread at the torch head, so exactly where you grip it for any job that takes more than a few seconds. There are few jimps on the rest of the handle, very flat, not very grippy. But the coarse heat spreader at the head is handy, and the perimeter fits my hands very well.
Disassembly
This thing has quite a lot of threads, as seen below. Tail clicky, removable insides of the clicky, a shaft consisting of two parts, the head section, a not-too-tactical crown, and I guess the driver pill is also removable with a spanner type screw driver of the appropriate size.
(#4 parts lined up)
Next up, the lens. Clear glass, the website says it’s coated. I wouldn’t bet on that. There are two scrapes at the rim, I guess the lens won’t break soon, but that’s an imperfection for sure. Yet, it doesn’t affect functionality at all. The head has some extensive threading and also an O sealing ring.
(#5 lens)
Now, in closer detail: Both sides of the reflector unit. The outer side is smooth, with some scruffy edges. Doesn’t really matter, I have a matte foil (from a laptop display) on most of my flashlights, so that I get a nice flooder. The inner side looks like it is made from a solid block, I don’t know if that is true. I suspect some chromed plastic on the front.
(#6 reflector, outer part)
(#7 reflector, inner part)
The driver chip. I didn’t want to show that in the first place, as I felt the wires would tangle when opening the unit. Well, they did when I wanted to unscrew another part of the flashlight. While the driver pill itself can rotate freely, it cannot when one wire is catched below the PCB and makes the rotation impossible. So I untangled it, noticed some isolation breaks, and the overall very thin and flexible wiring. Well, they could do better. And also, the 47ՠ25V capacitor could be a 105у model, as I bet the driver gets very hot during operation.
(#8 driver pill)
Backside of the lamp head. A not-really philips screw holds the reflector in place, which also fixates the LEDs. Very easy to open up.
(#9 head, backside)
The LEDs. Mounted on round heat sinks, no thermal grease or any other fixation. Wired in series, which makes sense when the driver is a 1000mA one as stated. Notice the brighter dots on the rim of the casing, there must have been some problem during surface treatment. But that’s invisible during normal operation. The other pattern in the center is due to machining, but that’s okay as well.
(#10 LEDs)
The tail clicky. I gave it some extra photos, but it’s hard to catch. There is a massive contact block (+ spring), but on top if it there is a leftover thorn from production. Inserting batteries and putting on the tail, this might penetrate battery protection PCBs or even unprotected cells. Also, this makes a tiny contact with high resistance, thus warming the unit up (eating battery life) just because of a bad connection. I removed it, very easy to do, but this shouldn’t pass QC at all. The clicky itself is not centered, which looks a bit odd. Functionality is not impaired by this. Moreover, the switch is a bit recessed, so that the lamp may stand on the tail. But remember, this thing weighs 450 grams and has a massive head, so standing on such a tiny area is quite unstable.
(#11 clicky)
(#12 thorn)
(#13 thorn again)
(#14 and another shot of the thorn)
Some threads in more detail. While overall quality isn’t too bad, some of them squeak, some of them are a bit loose, all of them require different forces to (dis)assemble. In the last picture, the spring solder point is shown, looks well made to me.
(#15 thread of the tube at the lamp head)
(#16 thread of the tube 1)
(#17 thread of the tube 2)
(#18 thread of the tube 3)
(#19 thread of the lamp head)
Performance
I used two current/voltage regulation lab power supplies to test the unit. I had a multimeter close to the lamp head (voltage check), directly feeding the inner contact spring and the outer casing. I had to switch to the larger one (TDK Genesys, 60V/12.5A), as the “sufficient” 30V/3A wasn’t able to drive the Hi mode. It can, as 3A aren’t required while on, but there is a huge initial power spike, which is well above 3A. I consider this a bit ugly for the batteries, although this can be as low as ~1C discharge rate. Anyways, I did the testing with the larger one.
| voltage | mode | amperage | wattage | comments |
| 8.00V | Low | 0.20A | 1.60W | - |
| 8.00V | Mid | 1.08A | 8.64W | - |
| 8.00V | High | 2.10A | 16.8W | - |
| 7.00V | Low | 0.28A | 1.96W | - |
| 7.00V | Mid | 1.33A | 9.31W | - |
| 7.00V | High | 2.46A | 17.2W | - |
| 6.00V | Low | 0.33A | 1.98W | - |
| 6.00V | Mid | 1.66A | 9.96W | - |
| 6.00V | High | - | - | Not possible |
| 4.0V | Low | - | - | Lowest operation voltage |
| 4.5V | Mid | - | - | Lowest operation voltage |
| 6.8-6.9V | High | - | - | Lowest operation voltage, temperature dependent |
So, as you can see, wattage is kept stable during battery discharge, with increasing conversion losses when voltage goes down. This means that the light output stays the same until batteries are empty - very good in my opinion.
Once the high mode stops working (at 6.8V total = 3.4V per cell under load), you have some juice left, but you should exchange them soon. The mid and low mode go much deeper in voltage, which means they are actually capable of deep cycling your batteries, making them (permanently) lose a lot of capacity, or entirely destroy them, unless protected cells are used. I didn’t include amps on the lowest voltages, as typical Li-Ion discharge curves do not allow high currents when the cell are close to empty. So you’ll rush into these voltage ranges, and as I said, should be careful once the Hi mode doesn’t work any longer. It still flashes briefly when activated, but doesn’t show constant output after that.
Besides that, ~ 16 watts of LED power also make me wonder about the 1000mA claim. As far as I know, XM-L T6 have typical operating voltages of 3V and about 1000mA. Which is 3W per LED, 9W for three LEDs. So this beast has to push the LEDs much higher in order to sink 16 watts of power. Not good for life time, however nice for light output. Cree claims short of 1000 lumens when at maximum operation conditions, therefore 3000 lumens claimed by FandyFire seem reasonable, unless Cree has some unrealistic values. I have nothing close to that to compare this flashlight to, but it really is insanely bright. Even with the diffusor mounted, which widens and softens the spots for a better distribution over a wider angle. Do not, under any circumstance, look into the beam. Your eyeballs may pop. And even if they don’t, you’ll go blind.
Real life performance
Well, beamshots are always nice. I can present daylight ones to you, but I cannot offer night shots. I tried with my old high-end phone, but the sensor is just too noisy at any shutter time and ISO setting. You won’t see much, and may underestimate the power of the torch. But you may check out the review from Racer here: Review: FandyFire STL-V2
(#20 stock configuration: close beam)
(#21 stock configuration: midrange beam)
(#22 stock configuration: a meter away)
For comparision, my usual setup with the diffusor film onto the glass lens. You’ll see the advantages of the floody beam, and as the flashlight has so much power, the luminosity loss in the central area isn’t much of a problem.
(#23 matte foil: close beam)
(#24 matte foil: midrange beam)
(#25 matte foil: a meter away)
I did however check visibility range at night. Turns out, at a large parking lot, I was able to see some camping vans at the other end in good detail, which were 100 meters away (verified distance). This was even in slight rain, so imagine a huge visible beam due to scattering along the way. And it was with the already mentioned matte film on the lens, which softens the three central spots in favor of flooding the area around. Under perfect conditions, I think spotting people or animals 150 to 200 meters away is realistic. And, gosh, they will notice you.
We also used the torch in our lab. We do physics experiments in ultra high vacuum conditions like in outer space, which is why everything is in bulky purpose-built stainless steel chambers. They have few and tiny windows, which are also far away from the central chamber, connected by thin pipes. It is very hard to get enough light in there to actually see what you’re doing. We have special light sources with 100 watt halogen spots, which transfer the output via optical fibers, making tiny, bright, focussed light spots. Compared with ordinary lights, they are fantastic. Compared with this torch, they are a joke. I totally prefer using the FandyFire for all operations now, and I finally can see in detail what I’m doing in the UHV chamber. Not too far from now, we might get some specialized LED spots for these windows, I’m eager to compare these to the FandyFire. I doubt they will outperform it, even if they are specifically made for this application…
Side note: Putting this thing on high onto your clothes, you feel an intense heat immediately. This is from both the infrared (warmth) radiation from the LEDs, as well as the converted energy from the visible light output, as it is absorbed in your clothing. Putting it on bare skin, the absorption takes place over a longer range, lowering the heat sensation. I haven’t experienced this from a flashlight yet, only from classic incandescent light bulbs.
Conclusion
To sum it all up: This flashlight is a beast. 3000 lumens seem credible, at 16W+ it eats batteries for breakfast, and the price of about 40 USD is very reasonable for this performance. However, overall quality could be better: The removal of the metal thorn at the clicky electrode was absolutely necessary to prevent serious battery damage, the glass lens was slightly damaged, and the sharp edges (not burrs!) will reveal the bare aluminium soon due to normal wear and tear. Out of five stars I grant three, subtracting one for the thorn thingy, and another for the totally unnecessary SOS and strobe functions on such a powerful device. This is just a bad habit of driver manufacturers, except for those who intend the flashlights for alien mothership landing guidance or the like, but has no real-life application. So, if you need brutal power at a low price and can deal with some imperfections, this is the flashlight for you. If you’re looking for a premium torch with sophisticated modes and tech specs, you need to look for a triple-18650 light elsewhere. Oh, and it can also be used for blinding burglars before battering them to death - all functions in one single device :bigsmile:
