Fenix PD36R Pro Review (2800 Lumens, 21700, USB-C)

Today I am taking a look at the new Fenix PD36R Pro. It’s an update on the previous light and includes a substantial increase in runtime. The light may look and sound familiar though because I took a look at the TK20R V2 earlier this year and it shares a lot of similarities with the new PD36R Pro. Thanks to Thrunite for sending this to me to review. 


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Packaging & Accessories

The light I have is an early production sample that was sent before the packaging was finalized. That said I expect a typical Fenix full retail package that’s designed to hang on store shelves in your local sporting goods retailer. Included in your light will be a Fenix 5000mAh 21700 battery, USB A to C charging cable, Nylon Holster, pocket clip, Lanyard, spare o-ring, user manual, and warranty card. There is a few accessories that are not included but will also work with this light like a remote pressure switch that screws onto the tail, 3 different rail mounts, and a diffuser cone. All of these are sold separately. 


Construction and Design

I am only going to hit the high points here, and let the photos and video do the rest of the talking. The light shares a lot of physical traits with the TK20R V2. The light is made from T6061 aluminum and nicely anodized black, there is a special edition red camo version too at some retailers. At the tail cap you have 2 protruding buttons, a larger round mechanical switch that takes a good amount of force to push, and then a smaller rectangle mode button. The light does not tail stand as a result.

The pocket clip only mounts on the rear of the light. The body tube has a concentric ring knurling-like texture on the body, this provides a good amount of grip and looks nice I think. The charging port is covered with a textured silicone cover that fits very tightly, below it is a small LED indicator to show the charge level while charging. Red when charging, blue when charged.

Internally there is a stiff spring at the front of the light as well as in the tail, threads are smooth, square cut and a bit dry. Up front, the head is glued in place and the bezel is machined into the head. There is an AR glass lens, a narrow deep smooth reflector, and a nicely centered LED. 



Since this is a pre-production light I don’t have the lanyard or holster that the light will ship with in it’s final form. What I can talk about is the pocket clip. It only attaches at the rear of the light and is relatively narrow for the size of the light. It’s stiff and does a good job of retaining the light in my front pocket, with about 1” of the light sticking out. In my medium hands, the light is a nice size without being too bulky.


Size & Weight

I measured the length at 5.74”, and the diameter at 1.09” at the head. Weight with the battery and clip came in at 6.00oz. The light IP68 water rated, which means it can survive 6.5ft of water for 30 minutes. The USB port itself is waterproof as well, so even if you don’t have the cover in place that won’t be a problem. Here are a few comparison photos with the Fenix TK20R V2, and some other lights. 


LED & Beam

The Fenix PD36R Pro is using the Luminis SFT70 LED in cool white. My Opple meter shows it as 5456k and 60 CRI in medium mode. In higher modes, it cools off slightly and has a slight green tinge to the beam to my eye (and meter). The beam has a large pronounced hot spot in the center and a large spill with some tint shift noted. Compared to the TK20R V2, the hot spots are a similar size but the spill is larger here on the PD36R Pro. The Parasitic Drain was measured at a low 4.0uA with the tail cap off. There was some PDM here, especially on lower modes but my eye or camera didn’t see it only my Opple meter did. 

Measured outputs vs Stated Outputs

All readings were taken at the 30-second mark. The light was cooled in cool water between measurements.


Turbo – Measured – 2160 Lumens Claimed – 2800 Lumens 77.14% of Claimed

High – Measured – 978 Lumens Claimed – 1000 Lumens 97.80% of Claimed

Medium – Measured – 349 Lumens Claimed – 350 Lumens 99.71% of Claimed

Low – Measured – 157 Lumens Claimed – 150 Lumens 104.66% of Claimed

Eco – Measured – 35 Lumens Claimed – 30 Lumens 116.66% of Claimed


Heat and Runtime

For my heat and runtime, I tested with the supplied Fenix 5000mAh battery, on my Texas Ace Lumen tube. Turbo starts out here a the claimed lumens but by 1 minute it’s stepped down to about 750 lumens because the heat was up to about 43C. It increases the output some in the next 20 minutes as heat dissipates, but the light has a substantial drop at about 2:10:00, then again at 3:20:00, and once more at 4:30:00, where it runs at it’s the lowest output for many more hours. Total runtime was right around 8 hours, and the light does flash in the last hour of use to indicate it’s the battery is low.

I then did a comparison between Turbo, High and Medium runtimes and there isn’t really any real surprises. Lower outputs are more stable and have longer outputs. 



UI here is very simple and it’s the same that was found on the TK20R V2.. The light has 2 buttons on the rear tail cap of the light. There is the larger power button which Fenix is calling the Tactical switch, it’s a forward clicky switch with momentary, and then the smaller button which they are calling the function switch. You can half-press the tactical switch to turn the light on in the last mode used before locking fully on. Once on you use the function switch to cycle through the 5 modes in a linear manner. The light does have memory mode. At any time you can press and hold the function switch to get to strobe mode. 



Recharging on the PD36R Pro is accomplished via the USB-C port on the side of the light near the head. The port cover is worth mentioning here, it’s very tight fitting, and can be a bit of a challenge to remove despite a small tab to pull on. You have wide access to the port so cable compatibility shouldn’t be an issue here. The light charged via C to C cables and PD chargers without a problem. One thing to note is that you can’t use the light during charging.

I charged the included 5000mAh battery (Rated at 4870mAh in my testing)  from LVP at 3.044V to Full at 4.227V in 4:13:00. The charging speed starts off slow for the first few minutes, then increase significantly with a peak of 2.5A before slowly declining. The total charge time was 4:10:00. One thing that was concerning was that the terminating voltage was slightly too high. Not sure if this was my multimeter or maybe due to the prototype nature of my light. When fully charged the side LED indicator goes from Red to Blue.


Final Thoughts

The Fenix PD36R Pro is a pretty large upgrade over the older PD36R in nearly all metrics and is overall a well-rounded flashlight. However, I can’t help to draw on the large number of similarities to the TK20R 2.0 that I reviewed earlier this year. Same LED, Same UI, Same battery, very similar performance, Same tail cap, and same clip. Where they differ is mainly in the charging port cover, and head size. The TK20R V2 is more of a tactical purpose, where as the PD36R Pro is more EDC/General use while also being capable of tactical use. 

It’s a well built light, one of the best USB-C port covers I have seen, and a very easy to use UI with the two dedicated buttons on the tail. I’ll give it a ding for not being able to tail stand and for not lacking a true moonlight mode of 1 lumen or less. 


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