Lumintop E21C Flashlight Review

Lumintop E21C Flashlight Review

The Lumintop E21C flashlight is a 21700 version of a popular flashlight with a bunch of features. It uses USB-C charging, and a 21700!

Official Specs and Features of the Lumintop E21C Flashlight

Here’s a link to the Lumintop E21C flashlight product page.

Lumintop E21C Flashlight Versions

There is only one version.


The Lumintop E21C flashlight alone is priced at $89.95.  A package that includes a cell is also available at $10 more.

Short Review of the Lumintop E21C Flashlight

Quite a fun light here.  The side emitters are nice and warm, and floody but not just floody – they provide a very even flood.  The front emitter has quite high output.  USB-C charging at over 1.5A means this is a great 21700 flashlight.

Long Review

The Big Table

Lumintop E21C Flashlight
Emitter: Luminus SST-40
Price in USD at publication time:
Cell: 1×21700
High Runtime Graph Medium Runtime Graph
Switch Type: E-Switch
Quiescent Current (mA): 0.24
On-Board Charging? Yes
Charge Port Type: USB-C
Charge Graph
Power off Charge Port with cell: all modes
without cell: all modes
Claimed Lumens (lm) 1600
Measured Lumens (at 30s) 1400 (87.5% of claim)^
Candela per Lumen 11.3
Claimed Throw (m) 280
Candela (Calculated) in cd (at 30s) 612lux @ 5.182m = 16434cd
Throw (Calculated) (m) 256.4 (91.6% of claim)^
All my Lumintop reviews!
Lumintop E21C Flashlight
Emitter: Side
Price in USD at publication time:
Cell: 1×21700
High Runtime Graph
Switch Type: E-Switch
Quiescent Current (mA): 0.24
On-Board Charging? Yes
Charge Port Type: USB-C
Charge Graph
Power off Charge Port with cell: all modes
without cell: all modes
Claimed Lumens (lm) 240
Measured Lumens (at 30s) 235 (97.9% of claim)^
Candela per Lumen 0.7
Claimed Throw (m)
Candela (Calculated) in cd (at 30s) 38lux @ 2.444m = 227cd
Throw (Calculated) (m) 30.1
All my Lumintop 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

Lumintop E21C Flashlight what's included

  • Lumintop E21C Flashlight
  • Charge cable (USB to USB-C)
  • Glow in the dark diffuser
  • Lanyard
  • Manual
  • 21700 to 18650 adapter (pictured below)

Package and Manual

Lumintop E21C Flashlight manual Lumintop E21C Flashlight manual

Build Quality and Disassembly

Lumintop E21C Flashlight feature photo

I didn’t do … “much” … disassembly of the Lumintop E21C flashlight.  By that I mean I didn’t do any disassembly.  I took the tailcap off, which you’ll do too unless you just let the 21700 cell you’re using live in the light.  There’d be nothing wrong with that at all.

Lumintop E21C Flashlight tailcap

That spring in the tailcap is very long and allowed me to use all the way down to the shortest unprotected flat top 18650 cells.  When installing the tailcap, you have to be somewhat deliberate to get the threads to grab, since you have to compress the spring and twist all at the same time.

Lumintop E21C Flashlight tailcap

Still, this is an upgrade to “the original” which I reviewed a while back.  The EDC05C has only a coin slot to aid in unscrewing the tailcap.

The build quality is very good on the Lumintop E21C flashlight.  The bezel is screwed in and has the 6-point connection style.

Size and Comps

  • Size: 123.8mm x 27mm (length x diameter)
  • Weight: 106g without cell

If the flashlight will headstand, I’ll show it here (usually the third photo).  If the flashlight will tailstand, I’ll show that here, too (usually the fourth photo).

Lumintop E21C Flashlight in hand

Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

And here’s the light beside my custom engraved TorchLAB BOSS 35, an 18350 light.  I reviewed the aluminum version of that light in both 35 and 70 formats.

Lumintop E21C Flashlight beside torchlab boss 35

Retention and Carry

Point number one of the Lumintop E21C flashlight is that there’s no pocket clip.  I don’t consider 21700 cell flashlights to be too big for pocketing, and as sleek as this one is, I think it’d still work.  But no pocket clip.

But what is there?  A metal loop that flips out for use as a lantern.  That’s handy and convenient.  You’ll also need this for tightening the tailcap after cell swaps.

Lumintop E21C Flashlight tailcap loop

That tailcap also holds a magnet, but it’s not suitable for holding the light horizontally.

Next is the included lanyard.


Power and Runtime

As stated above, the Lumintop E21C flashlight runs on a single 21700 lithium-ion cell.

Lumintop E21C Flashlight 18650 adapter

An adapter is included which fits around a single 18650 cell and prevents rattle.  As I had a Lumintop 18650 from another light I’d recently reviewed, I tested this flashlight with that Lumintop 2600mAh 18650 (not the green cell seen below.)

Lumintop E21C Flashlight 18650 adapter

The cell is installed in the usual way – the positive end goes into the body.

Lumintop E21C Flashlight 18650 adapter

Here are a couple of runtimes for the “front” emitter.  These are the highest two modes.

Lumintop E21C Flashlight runtime graph Lumintop E21C Flashlight runtime graph

I also threw in a runtime of the side emitter highest option.  Unfortunately, at around 20 minutes, my thermal sensor came off…  You can see that the light heated up quite a bit though, with these side emitters.  That’s a little bit surprising.  They must be fairly inefficient, to produce only 240 lumens and that much heat, and run for such a fairly short time.

Lumintop E21C Flashlight runtime graph

The indicating switch does give notice when cell voltage is low.  It’ll turn red, then blink red, and finally, the light does turn off.


Built-in charging is a great feature of the Lumintop E21C flashlight.  The charge port is USB-C.

Included with the package is a USB to USB-C cable.

As I’ve tried to start doing, I tested this charging two ways.  First “as intended” – USB to USB-C. Then with C to C.  As you can see the charts are nearly identical, and so C to C charging works too. Charging is quite quick too.  At nearly 2A, I’d say the light is more ideal for a bigger capacity 21700 cell.

Lumintop E21C Flashlight charge graph

Modes and Currents

Mode 1:

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Front High 1600 4m30s+4h 1400 3.85
Front Med 865 4h10m 902 2.23
Front Low 300 12h 210 0.47
Side High 240 4h30m 235 1.59
Side Med 175 6h15m 173 0.98
Side Low 85 14h 74 0.45

Mode 2:

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Front High 560 5h36m 433 0.96
Front Med 110 26h 96 0.22
Front Low 20 80h 25 0.05
Side High 150 8h 115 0.75
Side Med 40 24h 37 0.26
Side Low 10 80h 10 0.06

Pulse Width Modulation

PWM is observed with an oscilloscope on all modes but this PWM is fast enough to not really be noticeable in person.

Take note of the mode order here, because it’s the same I’ll use below.  And actually it’s the same as the two tables above.

Mode 1: Front L, Front M, Front H
Mode 1: Side L, Side M, Side H
Mode 2: Front L, Front M, Front H
Mode 2: Side L, Side M, Side H

For reference, here’s a baseline shot, with all the room lights off and almost nothing hitting the sensor.  Also, here’s the light with the worst PWM I could find.  I’m adding multiple timescales, so it’ll be easier to compare to the test light.  Unfortunately, the PWM on this light is so bad that it doesn’t even work with my normal scale, which is 50 microseconds (50us). 10ms5ms2ms1ms0.5ms0.2ms.  In a display faster than 0.2ms or so, the on/off cycle is more than one screen, so it’d just (very incorrectly) look like a flat line.  I wrote more about this Ultrafire WF-602C flashlight and explained a little about PWM too.

User Interface and Operation

Lumintop uses a single e-switch on the E21C flashlight.  As seen below it’s indicating in blue, but it also can be red and blink red.

Lumintop E21C Flashlight e-switch

It’s a fairly standard side e-switch, and has a nice responsive action.

Lumintop E21C Flashlight e-switch

Lumintop E21C Flashlight e-switch

There are five (5) mode groups on the E21C.  Lumintop (maybe a little confusingly) calls them “Modes.”  Mode 1 and 2 are the same exactly, but with different output levels.  Modes 3, 4, and 5 offer other things.  Here’s a UI table!

State Action Result
Off Click On (Mode memory for front emitter)
On Click Mode advance (LMH)
On Double click Switch between front and side emitters
On Hold Off
Off Click 10x or more Enter Mode (Group) selection.
In Mode selection Click after the desired mode Mode is selected˚
Off Hold 4s Lockout (Front emitter blinks very low to confirm)
Lockout Click Front emitter blinks to indicate lockout
Lockout Hold Momentary very front emitter output
Lockout Hold 4s Unlock

˚ When clicking 10x (or more) the light will be on (and probably bright.)  When you stop clicking, the light will go off (or “be” off).  At this point, you’ll need to pay attention closely because the blinks for mode selection are dim.  Mode selection covers both front and side emitters in one pass, but (interestingly), you can enter the mode selection while in either emitter output (and that’s the emitter(s) you’ll look to for the blinks.)

LED and Beam

The front emitter here is a Luminus SST-40.  This emitter is known for great output, and surprisingly doesn’t pull all that much current to do so.

Lumintop E21C Flashlight front emitter

The side of the Lumintop E21C is covered with Nichia emitters, but Lumintop does not say which.  Over those emitters is a glow diffuser.  This is not a soft diffuser like we’ve seen in the past from Lumintop.  The downside of that is it doesn’t come right out for me to identify these Nichias.

Lumintop E21C Flashlight front emitter

Lumintop includes a glow in the dark Pope hat for the E21C.

Lumintop E21C Flashlight pope hat

The smooth reflector for the front emitter provides a nice tight beam.

Lumintop E21C Flashlight front emitter

The photo shows how many emitters are used in the side light better than I expected – there are 8 Nichias.

Lumintop E21C Flashlight side emitter

Lumintop E21C Flashlight front emitter

I said it above, but you can see it very clearly here – the side light floods in an extremely even way!

Lumintop E21C Flashlight side emitter Lumintop E21C Flashlight pope hat Lumintop E21C Flashlight pope hat

LED Color Report (CRI and CCT)


These beamshots are always with the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure.

Tint vs BLF-348 ( 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 219b BLF-348 because it’s inexpensive and has the best tint!

Conclusion on the Lumintop E21C Flashlight

What I like

  • Nice build quality
  • Very evenly floody side emitters
  • Good output
  • USB-C charging at around 2A
  • Useful switch indication

What I don’t like

  • Inefficient choice for side emitters
  • No pocket clip
  • Price at $100 with cell


  • This light was provided by Lumintop for review. I was not paid to write this review.
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1 thought on “Lumintop E21C Flashlight Review”

  1. Hey there, thank you for the review. I have one question but i can’t find an answer anywhere so i hoped you could perhaps help me.

    I was about to purchase this light but then i noticed the SST-40 Emitter. Looking at your graphs (and beamshots) i see a CRI of abou 66 which is something i realy don’t like. I have a bunch of SST-20 4000K 95CRI emitters from Hank laying around.

    My question it: is it possible to swap the emitter or is the head or bezel glued on or something like that? Would i need any special tools to open the light “on the other end” (not the tailcap). Also can you roughly tell me the reflector diameter?

    Thank you!

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