Fenix E03R Keychain Flashlight Review

Here’s the Fenix E03R Keychain flashlight, a dual emitter red/white light with USB-C charging and an indicating e-switch.  Read on!

---

Official Specs and Features

Here’s a link to the Fenix E03R Keychain Flashlight product page.

Versions

There’s only one version of the E03R.

Price

These list for $37.00, has been marked down to $26.95, and the street price is more like $24.95 at nealsgadgets! (referral link)

---

Short Review

I like this light a lot.  The red could use levels (other than on and strobe).  Switch is good, charging is good… It’s a very sleek light too, which makes it fun to use.

Long Review

The Big Table

Fenix E03R Keychain Flashlight
Emitter:	Match CA18 (white) (Everlight 2835 (red))
Price in USD at publication time:	$24.95 at NealsGadgets.com (referral link)
Cell:	Internal
High Runtime	Medium Runtime
LVP?	Warning
Switch Type:	E-Switch
Quiescent Current (A):	?
On-Board Charging?	Yes
Charge Port Type:	USB-C
Chargetime
Power off Charge Port with no Cell?	Two low white and both red
Claimed Lumens (lm)	260
Measured Lumens (at 30s)	231 (88.8% of claim)^
Candela per Lumen	3.2
Claimed Throw (m)	42
Candela (Calculated) in cd (at 30s)	62lux @ 3.643m = 823cd
Throw (Calculated) (m)	57.4 (136.7% of claim)^
All my Fenix reviews!

^ Measurement disclaimer:  Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.

What’s Included

• Fenix E03R Keychain Flashlight
• Split ring
• Manual and other papers

Package and Manual

Build Quality and Disassembly

This is a bit of an unusual built light – it seems to be a “unibody” design with all the guts stuffed in from the front.  The build quality is very good, but I’d say the ability to disassemble this light is very low.

I’m not sure if this is a permanent installation dual optic but if you wish to remove it do so carefully, since finding a replacement will probably be difficult.

There are no seams anywhere on the body.

The switch and charge port are the only two holes in the body.

Size and Comps

Length: 1.85” (47mm)
Width: 0.94” (24mm)
Height: 0.47” (12mm)

Weight: 0.78 oz. (22g) including battery

This Nitecore TINI is the closest in size that I could think of.  The Fenix is (again) a single piece of metal, which I’d say is a nice feature over the TINI.

Retention and Carry

All that’s really included for carrying the E03R is a tiny split ring that attaches to the tail loop.  Through that split ring, you could attach keys or a lanyard or whatever.  There is no pocket clip and no magnet.

Power and Runtime

The E03R is powered by an internal 200mAh LiPO cell, which is not serviceable.  I do not know (but doubt) that Fenix offers a replacement service for these batteries.

There’s an indicating switch that can be activated without turning on the light.  Just click the switch (when off) and the switch will indicate in this way:
Green: >70% power
Green flashing: 40%-70% power
Red: 10%-40% power
Red flashing: <10% power

Power is also indicated every time the light is turned on.

Here are a few runtimes.  “High” is the highest output, claimed at 260 lumens.  I measured 231, and a stepdown beginning around 1m15s.

The light didn’t really turn off during these runtimes.  The switch does indicate remaining power, and there’s a stepdown to very low output, however.

With the built-in battery comes built-in charging as well.  This is by way of a USB-C port.  A charging cable is not included.  I have plenty of the right cables (USB to USB-C or USB-C to USB-C.  Connecting USB-C to USB-C only charges at 5V, however.  If you don’t have any USB-C cables, you should factor this into your price.  (Note: The Fenix website does say cables are now included as of 8/20/20.  But if you buy elsewhere you may or may not get one.)

The charge port cover is a secure press-in silicone cover, and the port is very well fit into the opening.

Charging is a very consistent 0.2A and requires around 84 minutes to complete.

Modes and Currents

Mode	Mode Claimed Output (lm)	Claimed Runtime	Measured Lumens	Tailcap Amps
High	260	45m	231	–
Med	80	1h15m	82	–
Low	30	3h	30	–
Eco	5	18h	–	–
Red	4	5h30m	–	–

Pulse Width Modulation

There is non-visible (very fast) PWM on the lower three white modes.  The red does not use PWM.

Red: (no PWM).

Here you can see a “baseline” – a chart with almost no light hitting the sensor.

Then there’s the Ultrafire WF-602C flashlight, which has some of the worst PWM I’ve seen. It’s so bad that I used a post about it to explain PWM! Here are multiple timescales (10ms, 5ms, 2ms, 1ms, 0.5ms, 0.2ms) to make comparing this “worst” PWM light to the test light easier. That post also explains why I didn’t test the WF-602C at the usual 50us scale.

User Interface and Operation

There’s an indicating e-switch on one side of the E03R.  The switch has a metal cover and is very pleasantly clicky.  There’s just enough texture so you’ll know which side of the light it’s on without extra effort, and it’s flush with the body.

The switch has some battery indicator functions which have been covered above.

Here’s a user interface table!

State	Action	Result
Off	Click	Battery Indicator
Off	Hold (0.5s)	On – White
Off	Hold (1.2s)	On – Red
Off	Double Click	Lockout (indicated by a double flash of white)
Lockout	Click	Indicator for lockout (two white flashes)
Lockout	Double Click	Unlock to Low
On	Hold	Off
On	Click	Mode advance (ELMH for white) (Red > Red Flash for red)

The UI is quite simple, but the Hold for on (of either emitter) did take some getting used to.

LED and Beam

There are two emitters in the E03R.  The white is a Match CA18, and the red is an Everlight 2835.  I haven’t experienced the Match CA18 before.  Both are behind a lightly frosted TIR.

With the switch on top, the white is on the right-hand side.  In the photo below, the switch is “up” and at left (facing you) is the white, with red being the more clear of the two.

These beamshots are always with the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure. These photos are taken at floor level and the beam hits the ceiling around 9 feet away.

Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)

I keep the test flashlight on the left, and the BLF-348 reference flashlight on the right.

I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!

Conclusion

What I like

• Good build quality – no seams
• Dual output
• Good use of indicating switch
• Very nice switch overall (the cover, the action, the size, the placement – everything about this switch is right)

What I don’t like

• Built-in (probably not replaceable) battery
• Could use lower output on red (even if the higher was removed).

---

Notes

• This light was provided by NealsGadgets.com for review. I was not paid to write this review.
• This content originally appeared at zeroair.org.  Please visit there for the best experience!
• For flashlight-related patches, stickers, and gear, head over to PhotonPhreaks.com!
• Use my amazon.com referral link if you’re willing to help support making more reviews like this one!
• Please support me on Patreon! I deeply appreciate your support!