Fireflies PL47g2

Fireflies PL47 Gen 2 flashlight review


Edit: there is a newer version, called the FireFlies PL47g2 2021 version, which we also reviewed.

If you follow for more than a few months you must have heard about Fireflies. If you are new to flashlight this might be a brand name you haven’t heard about. FireFlies has become pretty famous because of its great choice of LED emitters. Mainly targeting the flashoholics who care about beam tints. 

The PL47g2 is a very bright headlamp with the very popular Anduril flashlight firmware (please scroll down to see more information about the UI) and should produce about 4000 Lumens. Let’s dive into the review to see how trustworthy those claims are!

What you’ll get:

FireFlies continues to provide good quality packaging. The only downside is their manual. They still copy them onto normal copy paper. They include quite a nice amount of accessories.

  • Fireflies PL47g2
  • Lanyard
  • Pocket clip
  • Spare O-rings
  • Warranty card
  • Manual
  • Extra tail-cap with magnet
  • 18650 battery adapter
  • UI cheat sheet

Fireflies PL47 gen 2 specifications

Brand / ModelFireflies PL47g2
LumensMax 4500
Beam intensityn/a
Battery config.1*21700
ReflectorTIR optics
Review dateJanuary 2020

Handling of the light

Before we dive into the actual handling of the light, I was interested in knowing why they upgraded the PL47. Fireflies announced in this BLF thread that their first-generation PL47 had some “instability of quality”. Not so sure what that means, but I just wanted to let you know.

Although you can hold it like a flashlight, it’s actually L-shaped. This means that it is great for use as a headlamp. FireFlies included a pocket clip so you can actually attach it to your belt, and light up the road in front of you.

They also included a magnetic tail-cap, so you can not only attach it on your forehead, belt clip but also onto metal. I’m actually thinking about switching my Convoy C8 that is currently in my car with this one. In case of an emergency, it can be used in many places and directions. So if you’re looking for something multi-functional, this could be a candidate!

The switch is located on top of the head with 2 indicator LEDs beneath the translucent switch cover. It’s a typical electronic switch. I would recommend unscrewing the tail cap when storing or carrying it. Because of the flat tail cap, it can tail-stand very properly.

The headband isn’t such a success. The rubber rings are very elastic so it’s very easy to install the PL47g2, but it’s a little on the small side. I don’t have a very large head, but the PL47g2 is even in its biggest position still rather small. Keep this in mind when looking for a headlamp! It isn’t so much the diameter, but the strap that goes on top of your head is a little too short IMHO.

Build Quality, knurling, threads, and anodization

As you may have noticed, the Fireflies PL47 gen2 has no knurling on the battery tube, and the head is also pretty slippery. There must be a reason for it, but it’s very slippery to hold, especially with cold hands in winter. I would have preferred more aggressive knurling on the head. If you mainly use it as a headlamp, you don’t really need to worry I guess.

The tail-cap has some fine reading which makes it very easy to open and replace your batteries.

Anodization, on the other hand, is well down across the light. Threads are also done very well without any problems. The stainless steel clip doesn’t hold under strong pressure, but that is probably okay? When you play with this, be extremely careful because the anodization will damage when the clip jumps off.

LEDs, Lens, Bezel and Reflector

The Fireflies PL47 generation 2 is available in multiple tints.

  • 4x Nichia 219B SW45K 4500K R9080 CRI95 Max 2500lumens
  • 4x SST20 4000K FA3 NW  Max 2800lumens CRI95
  • 4x SST20 L5 6500K CW CRI66 Max 4200lumens
  • 4x CREE XPL HI V3 CW 6500K Max 4500lumens
  • 4x CREE XPL HI V3 NW 5000K Max 4500lumens

We are testing the SST20 4000K as well as the XPL Hi NW 5000K. The black version has the XPL Hi LEDs and the clear anodized aluminum version has the SST20 4000K.

It depends on what you would like to use it for as well as the kind of tint you like. I personally don’t dislike the very powerful XPL Hi 5000K at all, while the SST20 4000K is a little warmer.

The TIR optics have a 10 degrees beam angle, which means that they are more ‘throwy’ than ‘floody’. If you rather have wider TIR optics you should be able to replace them with other ones or buy some DC Fix from Boaz at Budgetlightforum. DC fix spreads the beam very smooth so you have a wider beam as well as softer edges. DC Fix all the way!

The secondary LEDs (AUX LEDs) are on when the light is shut off. They are light-blue colored, and as far as I know, you can’t choose the colors while ordering the PL47g2. The AUX LEDs have actually 3 modes,

  • Always On
  • Blinking
  • Always Off

You can change the from Always On to Blinking by 7 clicks when the light is shut off. Repeat the 7 clicks to change from Blinking to  Always Off. Repeat again to change from Always Off to Always On.

The bezel is press-fit according to Fireflies, so I’m not going to try to open it up! It’s actually made of stainless steel.


  • Length:  89.1 mm (  3.52”)
  • Head width:   27.8 mm (  1.097”) 
  • Head front to back: 40mm (1.590″)
  • Body diameter:  24mm ( 0.948”)


  • Empty with magnetic tail cap and clip:  82.5g (  2.91 oz)
  • With battery and magnetic tail cap and clip:  149.6 g (  5.28 oz)
  • Pocket clip: 3.1 gr
  • Magnetic tailcap 13.7 gr (0.48 oz)

EDC Flashlights

Some size comparison with other EDC flashlights:

From left to right: Zebralight SC700d (21700, XHP70.2), Lumintop FW1A (18650, XPL Hi), FireFlies PL47 gen2 (21700,XPL Hi) Sunwayman V10R Ti (18350, XML), Reylight Krystal (18350, Nichia), Lumintop Tool AA 2.0 (AA, XPL HD)

Image 3: Fireflies PL47 gen 2 and Acebeam PT40

Driver & User Interface:

The Fireflies PL47 gen 2 uses a firmware called Anduril. A Budgetlightforum member named Toykeeper wrote the code for the firmware.

By default, it uses a smooth ramping mode.

Check out the full Anduril UI manual here.

Keep in mind that the AUX LEDs are on by default. (7 clicks from OFF can change the AUX settings from On – Blink – Off)

From OFF:

  • Single-click: ON
  • Double click: High
  • 3 clicks: Battery check
  • 4 clicks: Lock Out
  • 5 clicks: Momentary On
  • 6 clicks: Muggle mode
  • 7 clicks: Aux configuration mode

Enter Special/Fun modes from OFF:

  • 2 clicks + hold: Strobe modes (Click, Click, Click and hold)
  • 4 clicks: Lock Out mode (momentary on: dim)
  • 5 clicks: momentary mode (Bright) ( you can only deactivate by breaking electrical contact between the batteries and the driver by unscrewing the body from the head.
  • 6 clicks: Muggle mode

From ON:

  • Single-click: Off
  • Double click: Turbo
  • 3 clicks: change ramping mode. Instead of a smooth increase, it has 6 little steps between Low and Max.
  • 4 clicks: ramping configuration mode (Problematic if you make some changes here by accident)
  • Press and hold: brightness ramps up.. release and press and hold again to ramp down.

Warning: When the light is ON, please be careful not to do click 4 times and change the ramping configuration mode. This can be annoying if you don’t know how to reset it. Fortunately, the newest update of the firmware includes a Factory Reset function!


Read the full manual on how to access and customize these modes. Also, see the firmware picture.

  • Blinky Utility mode: 
    • Battery check
    • Sunset Mode
    • Beacon mode
    • Temperature check
  • Strobe / Mood modes:
    • Candle
    • Bike flasher
    • Party strobe
    • Tactical Strobe
    • Lightning mode
  • Lockout mode (can’t use the light) (activate by 4 clicks)
  • Momentary mode (signaling/morse coding)
  • Muggle mode: (safer for children)
  • Configuration mode
  • Ramp config mode


  • From OFF: 4 clicks. To deactivate click another 4 times.

Final comments:

It’s great to see Anduril UI being used for so many types of flashlights. The only downside is the UI itself. Since it can be programmed in so many ways, the sellers/manufacturers don’t usually set the thermal configuration correctly.
On both of my copies, the were a few degrees off. This resulted in doing 2 consecutive days or runtime tests with strange results. Take a look at the bottom of the page.

That being said: this isn’t a flashlight problem! It’s a setting. You can set the correct temperatures if you want. See diagram on how to set them. From off you do: 3 clicks- 2 clicks- 2 clicks- 2clicks-4 clicks…. wait for the quick flashes and push the button 20 times if room temperature is 20 degrees, 30 times if the room temperature is 30 degrees Celcius.  (The light should have been off for long enough).

Batteries and charging:

Since the light is made to be short, it doesn’t accept any protected 21700 batteries like the Fenix ARB-L21-5000. You need to use unprotected 21700 batteries.

21700 batteries fit very snug and don’t rattle!

18650 battery adapter

FireFlies includes a 18650 battery adapter. Take note that this is only for short, non-protected batteries.

TIP: You can use protected 18650 batteries without the 18650 adapter, without any rattle!


Lumen and Amp measurements:

All output numbers are relative for my homemade Integrating Sphere and are now set up with an Extech SDL400 Lux Meter for measurements. For extremely bright flashlights (above 5000 lumens) I am adding an ND filter, either a Kenko PRO1D ND-16 filter or a Hakuba HG Wide 8x ND filter. The base measurement is done with a Convoy S2+ that has been tested at 137 lumens.

Amps were measured with a Fluke 77III, at the tailcap. Not at the LED! I measured Amps using the 7 steps output mode group.

Fireflies PL47G2, black XPL version, with Samsung 40T

Mode (Amps)Lumens
1: 0.01A2,63 Lm
2: 0.06A16 Lm
3: 0.20A56 Lm
4: 0.49A141 Lm
5: 1.06A307 Lm
6: 1.33A615 Lm
7: 1.84A1273 Lm
Turbo: 7.27A3343 Lm

Fireflies PL47G2, black Luminus SST20 4000K version, with Samsung 40T

Mode (Amps)Lumens
1: 0.012 Lm
2: 0.0614 Lm
3: 0.2051 Lm
4: 0.50128 Lm
5: 1.08273 Lm
6: 1.38A487 Lm
7: 2.05943 Lm
Turbo: 7.11A2207 Lm

The XPL Hi can produce about 50% more lumens than the Luminus SST20 4000K LEDs.


After a few days of testing (2 tests per day) and uploading the data I came to the conclusion that the Thermal Configuration was way off. The Black one’s temperature is more accurate than the Silver one. You can see that the runtime graphs are just plain stupid. They drop very quickly to a very low output. Black drops down to about 200 Lumens, and the Silver one drops to about 166 Lumens on Turbo and about 76 Lumens on High. I redid the runtime graph after setting the correct Temperature in the firmware.
The runtime graph looks very different now. But a little strange peak can be seen, as well as the increased output towards the end. Especially the spike at the beginning of the runtime looks strange.

Throw measurement:

Measurements were taken indoors with a professional Hagner E4-X Lux Meter. 
Using the high mode only, I get:

  • Silver SST20 4000K:  14500 cd = 120  m throw
  • Black XPL Hi:  15750 cd =  125 m throw


Beamshots were this time taken at start and 30 seconds. Tests were performed with the Lumintop FW3A, Lumintop FW1A and both PL47g2 lights.

Disclaimer: the flashlights were sent by the manufacturer for review.

Overall conclusion


  1. Nice accessories
  2. Bright
  3. AUX LEDs
  4. 21700 batteries for long runtime


  1. Temperature configuration was way off
Author Marco
Author Marco

Overall Rating: 4 stars: ★★★★

The Fireflies PL47g2 is an interesting flashlight with lots to offer. Not only the extremely versatile Anduril UI, which you may like or not, but also the amount of accessories. The clip and magnetic tailcap are great accessories. The headband can be used if you want to use these bad boys as a headlamp. There is really nothing to complain about at this moment (except for the wrong temp configuration, which is just a setting), so I was going to give 5 stars. After the runtime tests I’m not very confident with the output spike, so I’ll lower it to 4-stars. 

FireflyLite PL47 discount code

Fireflies has been rebranded to FireflyLite, so they are the exact same companies/flashlights.

Get 10% off at Firefly Outdoor store, using our exclusive discount code: 1lumen

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