[4K Review] Fenix LR35R Flashlight: The 10,000 Lumen Sunlight in My Hand

colight

Enlightened
Joined
Dec 6, 2013
Messages
304
Location
On Earth
This is a repost of a detailed review carried out by Tactical Reviews......

Can it be true? 10,000 lumens from a light you could fit in your pocket? In this review of the Fenix LR35R I put Fenix's claimed output figures to the test. As well as this companion review there is a full length video review, with behind the scenes insights into the testing. It turns out that this light went beyond the limits of my test equipment and meant making modifications to allow an accurate reading to be taken.

Fenix-LR35R-01-angle-P1380777.jpg


Here is the video review:


INDEX:
00:00-01:20 Intro
01:20-07:31 Looking over the LR35R
07:31-13:28 Measuring parasitic drain
13:28-19:56 Troubleshooting – comparing cells
19:56-20:43 Troubleshooting – benchmark measurements for sensor modification
20:43-24:28 Modifying the integrating sphere
24:28-26:02 Results – USB charging
26:02-26:57 Results – Thermal imaging
26:57-30:40 Results – Runtime Graphs
30:40-32:11 Results – Beam shots
32:11-33:35 Summary

What is in the box?:
As this is a pre-production sample, there is no un-boxing as only the light was supplied.

A good look round the LR35R – Things to look out for here are:
Be sure to check the video for many of these details.

The beam


Please be careful not to judge tint based on images you see on a computer screen. Unless properly calibrated, the screen itself will change the perceived tint.


The indoor beamshot is intended to give an idea of the beam shape/quality rather than tint. All beamshots are taken using daylight white balance. The woodwork (stairs and skirting) are painted Farrow & Ball "Off-White", and the walls are a light sandy colour called 'String' again by Farrow & Ball. I don't actually have a 'white wall' in the house to use for this, and my wife won't have one!

Batteries and output


The LR35R runs on two 21700 cells which can be recharged in the light.


Please note, all quoted lumen figures are from a DIY integrating sphere, and according to ANSI standards. Although every effort is made to give as accurate a result as possible, they should be taken as an estimate only. The results can be used to compare outputs in this review and others I have published.

Before getting onto the output graphs, let's quickly look at the USB charging graphs. Fenix have use a pulse charging approach which the three images show clearly. Peak charging current is 3A.

And the three runtime graphs which show the effect of the thermal regulation, and how this is countered with stronger cooling.

A thermal image taken during the runtime testing.

The LR35R in use


A real surprise that this output can be achieved in a light smaller than one of my old favourites, the TK35. It does heat up very quickly, and in normal use, hand held, the thermal regulation kicks in much faster than on the runtime graphs which had strong cooling.
The built in charging is very useful, especially as all the 21700 rated chargers I have would not take the long Fenix 21700 cells. It also means you don't need anything else, and can swap the cells if needed.
As the LR35R is so small, I really wish Fenix had added a lower sub-lumen mode, as for me that would make it a fantastic all-rounder.
Be aware that the headline 10,000 lumens is only short lived, but if you take it down a notch or two, the performance is very very strong.
Beam tint and beam profile are very useable, and overall this is a powerhouse that is easy to live with.

13-Fenix-LR35R-sky-beam-P1390009.jpg




Review Summary
The views expressed in this summary table are from the point of view of the reviewer's personal use. I am not a member of the armed forces and cannot comment on its use beyond that covered in the review.


Something that might be a 'pro' for one user can be a 'con' for another, so the comments are categorised based on my requirements. You should consider all points and if they could be beneficial to you.


_______________________________________________
What doesn't work so well for me
_______________________________________________
Lack of a sub-lumen mode.
Heats up very quickly.


_______________________________________________
Things I like
_______________________________________________
Hits that 10,000 lumen headline figure.
Very strong performance on High and Medium output.
Surprisingly compact.
USB-C charging built-in.
Comes with two high-capacity 21700 cells.
Great Beam tint and profile.
 
Last edited:

subwoofer

Flashlight Enthusiast
Joined
May 5, 2010
Messages
2,501
Location
Hove, UK
It certainly was an interesting one to do, and pushed my measuring equipment to the limit!
 
Last edited:

Folgore202

Newly Enlightened
Joined
Jul 30, 2020
Messages
10
Sounds pretty great, it looks like it'd be a nice option to have at night if my car breaks down in the countryside or something like that.
 

Alabama_Man

Newly Enlightened
Joined
Aug 1, 2020
Messages
3
This flashlight is the very reason I decided to join the forums, you know ;)

I am totally interested in getting my hands on it, yet, I'm always diffident towards 21700 battery cells: I got hundreds of 18650s, and I always try to force them into just about any battery-operated device.

I Wonder why guys at Fenix didn't design the LR35R to run on, say, four or six 18650s (series of two in parallel): it would have been a far better choce for a SHTF / emergency use.

By the way, Colight, have you tried using two 18650s instead of 21700s?
Can they work, with proper thickness fitting?
 

cancow

Newly Enlightened
Joined
Sep 18, 2006
Messages
157
Well, you could say that why didn't they make it a AA for SHTF. Besides, in 10 years 18650 will probably only sold for old devices. Tech is always changing and what is the norm today will eventually be a nich market.


This flashlight is the very reason I decided to join the forums, you know ;)

I am totally interested in getting my hands on it, yet, I'm always diffident towards 21700 battery cells: I got hundreds of 18650s, and I always try to force them into just about any battery-operated device.

I Wonder why guys at Fenix didn't design the LR35R to run on, say, four or six 18650s (series of two in parallel): it would have been a far better choce for a SHTF / emergency use.

By the way, Colight, have you tried using two 18650s instead of 21700s?
Can they work, with proper thickness fitting?
 

colight

Enlightened
Joined
Dec 6, 2013
Messages
304
Location
On Earth
Hi Alabama,

Thanks for your question. But frankly, I didn't try 18650s, and there is no recommendation in the manual for using 18650s.

This flashlight is the very reason I decided to join the forums, you know ;)

I am totally interested in getting my hands on it, yet, I'm always diffident towards 21700 battery cells: I got hundreds of 18650s, and I always try to force them into just about any battery-operated device.

I Wonder why guys at Fenix didn't design the LR35R to run on, say, four or six 18650s (series of two in parallel): it would have been a far better choce for a SHTF / emergency use.

By the way, Colight, have you tried using two 18650s instead of 21700s?
Can they work, with proper thickness fitting?
 

subwoofer

Flashlight Enthusiast
Joined
May 5, 2010
Messages
2,501
Location
Hove, UK
This flashlight is the very reason I decided to join the forums, you know ;)

I am totally interested in getting my hands on it, yet, I'm always diffident towards 21700 battery cells: I got hundreds of 18650s, and I always try to force them into just about any battery-operated device.

I Wonder why guys at Fenix didn't design the LR35R to run on, say, four or six 18650s (series of two in parallel): it would have been a far better choce for a SHTF / emergency use.

By the way, Colight, have you tried using two 18650s instead of 21700s?
Can they work, with proper thickness fitting?

In the course of carrying out this review I did use the Fenix 18650 / 21700 adapters and 20A IMR 18650 cells. Overall output was noticeably lower and the drop-off was faster. But this was on maximum output. It is perfectly usable on lower levels with 18650 (and appropriate adapters).
 

Swedpat

Flashlight Enthusiast
Joined
Jan 5, 2008
Messages
3,448
Location
Boden, Sweden
Thanks for the review!
Fenix was the first quality brand I started to buy and like in my early flashaholism. And this light looks similar as TK35 MTG2 which I like and still use occasionally.
But what is the reason I since a few years abandoned Fenix? The main reason is the user interface. Which LR35R also has. ALL modes memorised and NO direct access to any of them. What's the problem with that? Yes; at one occassion I find mid mode suitable. Another occasion I want turbo. Next time after that the lowest mode is the desirable. Oops! Turbo was activated...
Apart from that the function with a long click for on/off and a short click for cycling the modes is not good. Several times I have accidently stepped up a level in the modes, sometimes without noticing it.
LR35R is a nice looking light and I can understand of the size and design that it's comfortable in the hand.
With a better UI it would be really attractive for me.

Let me here tell why Thrunite and Acebeam now belong to my favorite brands: low, mid and high are memorised while firefly and turbo instead have direct access. This means I can have mid mode as a memorised allround mode, and always access to turbo when I want it(and never accidently). And always from off getting firefly without risk for activating a higher mode.
Worth to mention is also Fenix's restriction of neutral white option. Acebeam and Thrunite have it as a standard and offer it for almost all models.

This was just some constructive criticism. Maybe some representative for Fenix reads it and can persuade the engineers to improve their lights. I am not alone to welcome it!
 
Last edited:

325addict

Enlightened
Joined
Jan 7, 2009
Messages
978
Location
The Netherlands, Amstelveen
For me, the first quality LED-light also was a Fenix (P1D) and after that, the P3D came... but as I couldn't get used to that pale LED-color of light, I in fact conpletely abandoned LED lights for all uses except emergency use. I have tons of incan flashlights, some standard, some modified, some highly modified but all are very usable and I get an instant grin on my face whenever I switch on my 2.5D Mag with 4 pieces 18650 and WA1274 in it, or my Megalennium with WA1166 bulb in it. Jus before he went out of business, I bought goodies from Tad Customs worth over $400,- and I am ready to buy 3 lights from Fivemega, which will set me back even further than that amount ;-)

Thanks for the review!
Fenix was the first quality brand I started to buy and like in my early flashaholism. And this light looks similar as TK35 MTG2 which I like and still use occasionally.
But what is the reason I since a few years abandoned Fenix? The main reason is the user interface. Which LR35R also has. ALL modes memorised and NO direct access to any of them. What's the problem with that? Yes; at one occassion I find mid mode suitable. Another occasion I want turbo. Next time after that the lowest mode is the desirable. Oops! Turbo was activated...
Apart from that the function with a long click for on/off and a short click for cycling the modes is not good. Several times I have accidently stepped up a level in the modes, sometimes without noticing it.
LR35R is a nice looking light and I can understand of the size and design that it's comfortable in the hand.
With a better UI it would be really attractive for me.

Let me here tell why Thrunite and Acebeam now belong to my favorite brands: low, mid and high are memorised while firefly and turbo instead have direct access. This means I can have mid mode as a memorised allround mode, and always access to turbo when I want it(and never accidently). And always from off getting firefly without risk for activating a higher mode.
Worth to mention is also Fenix's restriction of neutral white option. Acebeam and Thrunite have it as a standard and offer it for almost all models.

This was just some constructive criticism. Maybe some representative for Fenix reads it and can persuade the engineers to improve their lights. I am not alone to welcome it!
 
Top