Author Archives: selfbuilt

Fenix E35 v3

The Fenix E35 v3 is a very compact every-day-carry style flashlight, featuring a moderately high output emitter and running on an included single 21700 battery. A TIR optic provides for very good throw.

  1. Introduction
  2. Manufacturer Specifications
  3. Package Details
  4. Build
  5. User Interface
  6. Circuit Measures
  7. Emitter Measures
  8. Beamshots
  9. Testing Results
  10. Runtimes
  11. Pros and Cons
  12. Overall Rating
  13. Preliminary Conclusions
  14. Acknowledgement

Introduction

Fenix is the maker that launched my interest in LED flashlights back in ~2006, so it seems only appropriate to start off my return to flashlight testing with their compact 1×21700 light, the E35 v3.

I recall the first generation E35 when it was released in 2012 – with a whopping max output of 235 lumens. 😉 At the time, it didn’t hold any interest for me. Around the time I wrapped up my reviews, a more interesting E35 Ultimate Edition, with an output of 1000 lumens, had come out. This third version (first released in 2020) is now rated at 3000 lumens, thanks to its Luminus SST70 LED emitter and included 21700 Li-ion battery.

Although this v3 model has been around for a couple of years now, it’s still a respectable contender in the compact 1×21700 EDC class that I plan to focus on in my upcoming reviews. So, let’s see what it has to offer.

Manufacturer Specifications

Note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results.

FeatureSpecs
MakerFenix
ModelE35 v3
EmitterSST70
Tint-
Specs Max Output (Lumens)3,000
Specs Min Output (Lumens)50
Specs Max Runtime50 hrs
Specs Max Beam Intensity (cd)14,400 cd
Specs Max Beam Distance (m)240 m
Number of Levels5
Flashing ModesStrobe
Battery1x21700
Weight (w/o battery)67 g
Weight (with battery)-
Length118 mm
Head Diameter26.5 mm
Body Diameter26.5 mm
WaterproofIP68 2m

Package Details

(edited) 20230319_135511
(edited) 20230319_141950
(edited) 20230319_135532

The E35 v3 is shipped in standard retail store packaging, suitable for mounting on a display peg. This means you will need a pair of scissors or knife to open the sealed bubble plastic. Inside, you will find the following:

  • Fenix E35 v3 flashlight
  • Fenix 21700 USB-C rechargeable Li-ion battery (5000mAh)
  • USB-C charging cord
  • Pocket clip (attached)
  • Wrist lanyard
  • Spare o-rings
  • Manual, product brochure, and warranty card

It’s a reasonable package of accessories, but I do miss the old-style Fenix elasticized belt holster.

Build

20230402_162025
From left to right: LiitoKala 21700 (5000mAh), Fenix ARB-L21-5000U 21700 (5000mAh), Sofirm IF25A, Fenix E35 v3, Convoy S21E, Imalent MS03, Armytek Wizard C2 Pro Max, Acebeam E70, Nitecore P20iX, Nitecore MH12SE, Lumintop D3, Convoy M21F.

(edited) 20230319_135617
(edited) 20230319_135629
(edited) 20230319_135749
(edited) 20230319_135645
20230319_135813
(edited) 20230319_135847
(edited) 20230319_135911
(edited) 20230319_135859

The E35 v3 is among the most compact of the 1×21700 battery class of flashlights I’ve seen. The extra width of the 21700 cell (over standard 18650) is barely noticeable, and the light fits well in the hand.

The side switch is in a convenient location for traditional flashlight carry, as your thumb rests naturally on the switch. Note there is no tailcap switch, so there is no easy option to carry the light in overhand tactical stance (i.e., you would need to use your little finger on the switch if you did).

The light lacks traditional knurling, and has instead a series of fine concentric rings (which I have sometimes seen referred to as “reeling” instead of knurling). Frankly, I find these rather slippery here – I’ve definitely come across more substantial implementations of this design.

The pocket clip helps with grip, so I recommend you leave it attached (as there are few other protruding design elements). The pocket clip seems designed for downward carry, but you could in a pinch try to mount the light between the clip and body so that it is pointing upward instead. The clip is not physically reversible on the light.

Tailstanding is stable, and there are cut-outs along the raised side ridges for lanyard use.

Hard anodizing looks to be good quality (as is typical for Fenix), and is more on the glossy side than typical (I personally prefer more matte). Threads are anodized, so you can lock out the light by a twist of the head.

The power switch has a metal cover, with a clear centre to allow the integrated battery status LED to shine through (see User Interface below). Switch feel is decent for this style of light.

The light lacks a USB-C charging port on the body, but there is one built into the bundled battery. Given the extra length of these batteries, you’ll have to stick with ones that include such a port (and a pronounced button, as required in this case by the reverse polarity feature). Since the Fenix battery is quite long, I think you will find that few other brands will fit and work in the light (i.e., none of the other ones with integrated USB-C chargers that I have tried would work).

(edited) 20230319_135658
20230319_135714
(edited) 20230319_140046

The light apparently uses a Luminus SST70 LED – but not that you can easily tell, as the TIR optic obscures a clear view of the emitter die. I’m not generally a fan of TIR optics, but this one does an excellent job – a great balance of throw and wide spill, with no real colour distortions over the beam profile. Scroll down to see my beamshots below. That said, the lower output modes do have a noticeable green tint. This is not uncommon on Fenix lights, as constant-current drivers tend to produce more of a green hue at lower drive settings.

The bezel has a copper-colour ring that is completely flat (i.e., no crenelations). So if you lay the light down on its head on a flat surface, you may not be able to easily tell if it is on.

There is a reverse polarity feature in the head, so only true button-top cells will work in the light. I tried a few other 21700 cells, and none would activate the light.

Overall, I find this to be a good looking light with decent ergonomics and a great beam pattern. It fits well in the hand, but is a bit slipperier than I would like. A nice build in the compact 1×21700 EDC class.

User Interface

The E35 v3 uses a single side-mounted switch to control the flashlight. Available constant output modes, as per the manufacturer labels, are: Eco, Low, Medium, High, Turbo. There is one blinking mode outside the main sequence: Strobe.

From OFF:

  • Press and hold 0.5 sec: Turns ON (constant output)
  • Press and hold 2 sec: Strobe
  • Single click: Battery status
  • Double click: Lockout
  • Triple click: n/a

From ON:

  • Press and hold 0.5 sec: Turns OFF
  • Press and hold 2 sec: Strobe
  • Single click: Cycle through Eco to Turbo, in repeating sequence
  • Double click: n/a (it just cycles through the constant output modes)

Mode memory:

Yes.

Low battery warning:

Yes. The indicator LED under the switch will show the remaining power as follows; Solid Green (85-100%), Flashing Green (50-85%), Solid Red (25-50%), Flashing Red (1-25%). It is bright without being obtrusive.

Reviewer Comments:

I really don’t like this interface. I find clicking to advance modes to be counter-intuitive, and I kept advancing to the level every time I tried to turn the light off during my testing. I can normally live with press-hold for on (although prefer single click). But in this case it was ruined by putting strobe as the extended press-hold. So, if you hold the button down for a fraction of a second too long (when either trying to turn on or off), you wind up strobing yourself (which again happened to me repeatedly in my testing)!

Personally, I find this the worse of all possible worlds. I suppose if this is the only flashlight you own, you will get used to it eventually. But having handled an insanely high number of flashlights over the years, I find this sort of non-traditional pairing very annoying (especially for the strobe placement).

I am also sad to see the lack of a true moonlight mode (see Testing Results for more info). This is a real shame, reducing the usefulness of this light as an EDC.

Circuit Measures

Pulse-Width Modulation (PWM):

E35v3-Eco

There is no sign of PWM or circuit noise at any level. The light appears to be fully constant-current controlled. 🙂

Strobe:

E35v3-StrobeB
E35v3-StrobeC

Strobe alternates between two defined frequencies every second or so, measured as 14.7 Hz and 6.0 Hz in my testing. Certainly very disorienting!

Charging:

(edited) 20230319_135942

Resting voltage <3.0V
E35v3-charging1

Resting voltage >3.0V
E35v3-charging2

The Fenix 21700 battery shows an initial low USB-C charging current of 0.12A when the cell is heavily depleted (<3.0V resting), which jumps up to 1.25A once the cell is >3.0V resting. This is a good design, and indicates a safe and reasonably rapid integrated charging circuit.

Standby / Parasitic Drain:

I measured the standby current as 35.5 uA.

This is negligible and not a concern for long-term battery life, but I always suggest you lock the light out when not in use to prevent accidental activation. A single twist of the head will lock out this light, thanks to the anodized screw threads.

Emitter Measures

This section is a new feature of my reviews, where I directly measure key emitter characteristics in terms of colour temperature, tint, and colour rendition. Please see my Emitter Measures page to learn more about what these terms mean, and how I am measuring them.

As explained on that page, since I am using an inexpensive uncalibrated device, you can only make relative comparisons across my reviews (i.e., don’t take these numbers as absolutely accurate values, but as relatively consistent across lights in my testing).

The key measures above are the colour temperature of ~5160K, and the very noticeable positive tint shift (+0.0199 Duv) to green-yellow at this temperature.

For CRI (Ra), I measured a combined score of 61.

These results are consistent with high output Luminus SST emitters, and match my visual experience of this light.

Beamshots

All outdoor beamshots are taken on my Canon PowerShot S5 IS at f/2.7, 0.5 secs exposure, ISO 400, daylight white balance. The bend in the road is approximately 40 meters (~45 yards) from the camera. Learn more about my outdoor beamshots here (scroll down for the floody light position used in this review).

Click on any thumbnail image below to open a full size image in a new window. You can then easily compare beams by switching between tabs.



Testing Results

My summary tables are generally reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. In addition to the links above, please see my output measures page for more background.

All my output numbers are based on my home-made lightbox setup. As explained on that methodology page, I have devised a method for converting my lightbox relative output values to estimated lumens. My Peak Intensity/Beam Distance are directly measured with a NIST-certified Extech EA31 lightmeter.

Fenix E35 Testing Results

ModeSpec LumensEstimated Lumens @0secEstimated Lumens @30 secsBeam Intensity @0secBeam Intensity @30secsBeam Distance @30secsPWM/Strobe FreqNoise FreqCharging Current <3VCharging Current >3VParasitic DrainWeight w/o BatteryWeight with Battery
Eco506969---NoNo0.12 A1.25 A35.5 uA68 g141 g
Low150200200---NoNo0.12 A1.25 A35.5 uA68 g141 g
Med450530530---NoNo0.12 A1.25 A35.5 uA68 g141 g
Hi1,2001,4001,350---NoNo0.12 A1.25 A35.5 uA68 g141 g
Turbo3,0003,0002,90015,150 cd13,710 cd234 mNoNo0.12 A1.25 A35.5 uA68 g141 g
Strobe3,000-----14.7 Hz / 6.0 HzNo0.12 A1.25 A35.5 uA68 g141 g

To see full testing results for all modern lights in my testing, check out my Database page.

Runtimes

As always, my runtimes are done under a small cooling fan, for safety and consistency. To learn more about how to interpret runtime graphs, see my runtimes methodology page.

E35-Max

E35-Hi

E35-Med

As you can see above, the E35 is extremely efficient at all levels tested, consistent with a good current-controlled circuit.

I know the runtime pattern looks rather “noisy” on Turbo, but this is not actually visible to the naked eye. To illustrate, here are the max output runtimes blown-up to show the first 8 minutes:

E35-Max-Expanded

And now, an even greater blow-up of 2 mins in the middle of the run:

E35-2min

The gradual rise, and somewhat faster fall, in output are not visible to the naked eye as they happen over quite a few seconds. For all intents and purposes, the output appears completely stable in actual use.

Pros and Cons

ProsCons
Outstanding current-controlled efficiency
No Moonlight mode
Excellent balanced beam profilePoorly thought out user interface, easy to strobe yourself when turning on/off
Good thermal management allowing for reasonably high output levelsSomewhat slippery design
Very compact light
Included high-capacity battery with fast built-in charge rate

An additional neutral comment (i.e., not necessarily good or bad) is that only true button-top cells will work in the light. This is due to the reverse polarity protection feature.

Overall Rating

Preliminary Conclusions

I was really expecting to be able to award this light a higher rating when it first arrived. Fenix’s current-controlled circuitry has always had top-notch efficiency, with some of the best runtimes in the business (which is true here too). Although the lack of a moonlight mode was always going to bring it down from top status though – this is a fatal flaw in an EDC light, in my opinion.

I can handle the minor annoyances I found in testing (like the slippery finish), given all its other positive (e.g., its compact size and lovely beam). But the user interface is just bonkers to me. Who makes you long-press to turn on or off, but then makes strobe a slightly longer press? This is a recipe to strobe yourself when turning on or off (which I did repeatedly). Also not a fan of click to advance modes (i.e., easy to forget, so you wind up jumping to a higher level when you meant to turn off). Sorry, but this lack of forethought turns what is an otherwise top quality package into one that is just above average overall.

But it is all relative in the end. If you the user interface makes sense to you, or you figure you can get used to it, this light does have a lot to offer. The relatively high (and well-managed) output levels, the excellent runtime efficiency, and great beam pattern make it a serious contender in the the ultra-compact 1×21700 class of flashlights.

Reviewer’s Note: Between the time of my purchase and this review, Fenix has released a slightly updated version known as the E35R. But this has very minor tweaks – a tiny bump in max output to 3,100 lumens, inclusion of a USB-C charger on the light itself instead of the battery, slight body change with magnetic tail, and minor UI tweak for lockout. I doubt performance would be meaningfully different to what is described here, and none of the changes affect my conclusions about handling or the interface.

Acknowledgement

I personally purchased this light from a local dealer. This review has not been sponsored in any way. At the time of review, this light retails for ~$75 USD (~$105 CDN).

My (Limited) Return to Flashlight Reviewing – Part I

Some of you out there may remember me. 🙂

Beginning in early 2007, I started posting personal reviews of flashlights I owned on the main online flashlight discussion forum at the time, candlepowerforums.com. I had initially modeled my reviews after the (now long-since extinct) flashlightreviews.com run by Doug P. (aka Quickbeam on cpf). But there was a distinctive defining feature of my reviews –  direct comparative testing of different models of the same class within each review. I will come back to this point at the end of this post.

My reviews quickly became popular, and by the end of that year manufacturers’ started contacting me to review their lights. Within a year, most of the major manufacturers were sending me lights to review. And by the time I wound down my review testing in early 2016, I had reviewed nearly 600 flashlights (not to mention about two dozen massive round-up comparison reviews, broken down by battery class).

So why did I stop, and why am I making a (limited) return?

The answer to the first part is a combination of life getting in the way and waning interest, for reasons I’ll explain below. As for my return, I’ll cover that in a part II post.

As was likely obvious from my reviews, I have research background. Indeed, one of my innovations was to structure my reviews roughly in the format of a scientific research paper – something that is common now, but basically unheard of when I started. But as a successful professional in my own field, my work responsibilities continued to expand to the point where I had little free time left anymore – and couldn’t handle the flood of requests I was getting.

I was also getting less satisfaction from the reviews. I had found the pace of innovation in flashlight design and performance had really slowed down. Through most of my time as a reviewer, overall LED emitter output was easily doubling every 12-18 months. And those early years saw huge explosions in innovative circuit designs  – with increasingly efficient constant current regulation and tons of specialty modes – and huge experimentation in user interfaces (e.g., visually-linear ramping outputs, intuitive magnetic control rings, etc.). And of course in the beam patterns – as a result of diverse designs and layouts in terms of emitters, reflectors, optics, etc.

But by ~2015, LED technology had largely fully matured, without the previous leaps in performance I had seen. An endless variety of me-too lights crossed my threshold that didn’t offer anything significant over what had come before.

Even worse, I was seeing increasingly the loss of useful features and designs, as manufacturers reverted to simpler and cheaper circuits (but with increasingly rakish physical designs, to distract you from the lack of substance). For example, formerly “hidden” modes were increasingly showing up in main sequences or too easily accessed (i.e., you could far too easily “tactically strobe” yourself now). The very useful “moonlight” modes for dark-adapted eyes were rapidly disappearing. And visually-linear ramps were turning into a joke with speeds so high that you could barely access a couple of discrete levels, etc.

Some of the other key drivers for my reviews had also diminished over time. I have always been singly focused on the truth when it comes to reviewing – by providing accurate, independent testing. While ANSI FL-1 standards were far from perfect, their widespread adoption at least helped to level the playing field in terms of reported specs – assuming makers were accurately representing their lights (which, while far from perfect, did improve over time and were fairly accurate by that point).

Moreover, when I started, there were very few truly independent flashlight reviewers out there. As many others joined the field, and started producing their own detailed reviews, I felt the need for my own personal reviews had lessened somewhat – there were plenty of others out there to pick up the torch (pun intended).

That said, I was concerned about how many other reviewers out there seemed to be more focused on producing glossy-looking outdoor photographs of flashlights than they were on rigorous comparative testing. Intentional or not, these glitzy presentations were serving as free marketing tools for makers. I don’t mean to cast shade on my fellow reviewers here – I believe the vast majority were simply focused on producing the highest quality reviews possible, and they had far more photographic experience/skills than scientific. But the end result was a not-so-subtle shift of reviews being used are marketing tools, which I didn’t enjoy (and didn’t want to be a part of).

The intervening years

I haven’t been entirely absent from the online reviewing world in the intervening years – but I moved on to a (somewhat) less labour-intensive hobby, yet one that involved even more of my quantitative analysis skills and interest: whisky reviewing. 🙂

More specifically, since 2016 I have been running a meta-critic review site for whiskies (whiskyanalysis.com), where I integrate reviewer scores in a statistically-rigorous way for popular bottlings. Here is a little background on the methodology, with links through the rest of the site on everything you (n)ever wanted to know about how to integrate reviewer scores (not to mention the actual database, which is based on >25,000 individual review data points). It’s true that I did my own reviews there too, but these were just personal sensory analysis – they didn’t require all the long-hours of testing and review preparation as for flashlights.

To be honest, my interest there has also waned in recent years – ironically for many of the same reasons as I left flashlight testing. With the rising popularity of whisky in recent years (and the unchanged need for extensive barrel aging), the field has similarly become saturated with an increasing array of lower quality bottlings – put out at an ever increasing frequency to distract the public from the lack of substance. And as many established whisky reviewers wind down their own reviewing, and an increasing number of less-experienced reviewers join the field, it has become harder and harder to find the consistent reviewers that I need to build up the statistical models to integrate quality reviewer scores.

It’s ironic in another sense – the one thing I always resisted in my flashlight testing was an overall score or rank of the lights I reviewed. That’s because I wasn’t trying to give you an overall impression of a light, boiled down to a single number.  I wanted to show you how a given light compares to others in its class, on all the independent scales that you may care about, so that you can make your own decision based on the extensive comparative data. Whisky reviewing was quite different – you can statistically divide whiskies into flavour categories by cluster analysis, so knowing the relative quality of a particular bottle in a given flavour cluster was what actually mattered (and where I could add value by developing and maintaining the meta-critic).

So where do we go from here?

Or put another way, why I have come back to flashlight testing?  That question has a number of facets as well, which I think I’ll save for the next post.

 

 

1 3 4 5