REVIEW: Nitecore Concept 2 Flashlight

Bdm82

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The Nitecore Concept 2 is Nitecore's newest and brightest flashlight. It hits 6500 lumens, has an internally rechargeable 12400mAh battery, and features a remarkably small and sleek design.
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Here are the key specifications as tested:
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Skip to the commentary section at bottom to read more subjective notes on the Concept 2.


Disclaimer: This light was provided at no cost by Nitecore Store, shipping from their location in Texas. Nitecore Store is an authorized Nitecore distributor for the U.S.A. Retail price at the time of this review was $199.95.



Unboxing

The Concept 2 arrived in a modern looking, premium-feeling box. A similar approach was used with the Concept 1; this really sets the Concept line apart from other Nitecore models that ship in black and yellow retail boxes packed with specifications.
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Both box sides simply say "Concept Series".
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The rear does list specifications.
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Inside the box, a piece of foam hides (and protects) the Concept 2. Nitecore Store also included a quick reference sheet to warn users that the light ships in lockout mode – and will get hot when used on high modes in normal use.
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Top foam removed, the Concept 2, charge adapter, holster, and accessories are presented. Note the Concept 2 is very well padded.
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The Concept 2 comes with a lanyard pre-installed, holster, charge adapter, spare switch boot, spare charge port cover, manual, and warranty card. As always, it's great to see spares included for the rubber items that may wear out some day.
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The manual is in 10 languages (English, Spanish, German, French, Russian, Japanese, Chinese, Italian, Romanian, and Korean); each language's section is complete as the text is quite small.

It is online here:

Nitecore backs the Concept 2 with a 2-year warranty. Note that this is shorter than the usual 5 year Nitecore flashlight warranty though longer than the 12-month warranty that covers other rechargeable products.



Design

Nitecore describes the Concept 2 as "futuristic" in the marketing materials and it does look more modern than traditional flashlights. Like the Concept 1 I reviewed here, the Concept 2 is clean and simple. The difference of course is that the Concept 2 has much higher outputs, 4 emitters instead of 1, and has a large capacity internal battery rather than using a single 18650. The square tube design also sets it apart.


Nitecore lists the length at 112.5 mm, width at 40 mm, and weight at 348 g. My measurements confirmed the specifications exactly.

For a size comparison, here is the Concept 2 with other flashlights (and the batteries they use).
L to R: Olight R50 Pro (26650), Nitecore TM03 (18650), Nitecore Concept 2 (internal), Nitecore EC4SW (18650*2), ThorFire VG-15S (18650), Efest 26650 battery.
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The 12400mAh capacity is achieved via four 3100mAh 18650 cells sealedinside. Here the Concept 2 is next to the BLF Q8 – a light that also uses four 18650 cells. The Q8 also has 4 emitters – yet notice how much smaller the Concept 2 is!
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The head has a flat bezel attached by 4 small allen head bolts.
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The glass is A/R coated, the emitters are centered, and the 4 overlapping reflectors are free of defects.
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Towards the head of the Concept 2, just above the switch, is a HOT warning. The switch is semitransparent black rubber and is quite easy to find in the dark. Behind the switch is the Nitecore logo and website URL.
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The switch is backlit with a blue LED; the switch will blink to indicate battery voltage, lockout, or when charging. It is solid when charging is complete and off in normal use.
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Another side has the model name and registration/disposal information.
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The charge port and pocket clip utilize the other two sides. Note that the Concept 2 lacks traditional knurling. Still, the size and rounded corners do provide sufficient grip.
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The tail is a flat square, also retained by small allen head bolts. One corner has a single cutout for a lanyard. It appears that the pocket clip can be removed independently, though this was not confirmed. Note that the hole is relatively small, so threading the lanyard is not easy.
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Nitecore advises against disassembling the flashlight. With the internally rechargeable battery, no regular maintenance (such as thread lubrication) should be necessary.




Accessories

Pocket Clip
The MT22C's pocket clip is designed for head-down carry only. Given the size of the Concept 2, it is unlikely to be carried inside a pocket like a smaller light might be, but it is effective for clipping to a belt.
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Holster
The holster is the same overall design that is found with many other Nitecore lights. The canvas is thick and strong, a hook-and-loop flap keeps the Concept 2 secure, and space is ample enough to accommodate the pocket clip. On the back of the holster, a d-ring, belt loop, and hook-and-loop flap on the back provide multiple carry options.
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Lanyard
The lanyard is of good quality with a tight knit and a comfortable neoprene wrist strap. The hole for the lanyard to thread is very small and difficult to thread.
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Performance


Beam
The quad XHP35 HD emitters with overlapping smooth reflectors produce a round hotspot surrounded by pedals of corona and spill as is the norm with multi-emitter lights.
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Tint & Temperature
The color and CCT are not advertised by Nitecore though results were similar to other XHP35 HD lights tested from Nitecore. I found the hotspot was neutral (about 5300K) and barely yellow/green. The spill was cool (about 6400K) and had a light blue tint. Overall tint would be described as cool.

To demonstrate the overall color balance, here is the Concept 2 surrounded by lights with emitters of various tints and temperatures. Camera W/B set to daylight.
L to R: BLF348 (5000K 219B), Convoy S2+ (6500K XM-L2 U2 1B), Nitecore Concept 2 (XHP35 HD), Nitecore EC23 (XHP35 HD E2), Lumintop Tool Cu (4000K 219B)
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Output
Note: The internal 12400mAh battery was used for all tests. Ambient temperature was 79F +/- 3F. An 80mm PC fan was used to provide airflow mimicking real-world use.

Turbo is rated for 6500 lumens and 30 minutes, though the runtime is theoretical ased on performance without temperature regulation kicking in. The Concept 2 has Nitecore's Advanced Temperature Regulation (ATR); ATR adjusts the output based on temperature.

In normal Turbo testing, I measured 6422 lumens at turn-on and 5914 lumens at 30 seconds. At just over 30 seconds, the temperature regulation kicked in and output dropped to about 1200 lumens. It recovered slightly before dropping further to a bit over 800 lumens by the 1 minute mark. It recovered to nearly 2100 lumens at 5 minutes, then settled in at about 1785 lumens by minute 10. It declined ever-so-slightly from there until about 2:40 into the test. It powered off from 755 lumens at 2:48 – exceeding the 30 minute runtime dramatically.


Note that Turbo can be accessed one of two ways – either in the normal 5 mode rotation – or in momentary burst mode by holding the switch halfway from any other mode. In burst mode, turn-on output was 6584 lumens with 6122 lumens at 30 seconds. Burst mode is thus able to achieve slightly higher output than the regular mode.

Maximum external temperature was measured at 129F (54C) at about 30 seconds. The light stayed warm but not uncomfortable to hold because of the step-downs.


Turbo, first 15 minutes:
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Turbo, full runtime:
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High is rated at 2500 lumens for 1:30. I tested 2961 lumens at 30 seconds with runtime of 2:52. The High output curve was similar to Turbo after stepping down at minute 5.
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Medium is rated for 1000 lumens for 6:30. I tested 1141 lumens at 30 seconds and a runtime of 4:29, with the output level being very flat throughout the duration. Output exceeds but runtime falls short of specifications.
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Low is rated at 285 lumens for 16 hours. Output was measured at 306 lumens; runtime was not tested.


Ultralow is rated at 1 lumen for 200 hours. Output was measured at 1.6 lumens. Runtime was not tested.



All output levels:
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All runtimes tested:
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Amperage Draw
Not measured due to internal nature of battery.



Throw
I tested throw distance at 1.46 meters and candela measured 40991 at 30 seconds - equivalent to 404 meters of throw. Nitecore's specifications are 39700 Cd and 398 meters, in line with measured results.



PWM
Nitecore advertises the Concept 2 as constant current – and I found no signs of any PWM during testing.



Parasitic Drain
The dual-stage side switch is electronic, so some parasitic drain is to be expected. This wasn't measured due to the internal nature of the battery cell, but the manual states "Recharge the flashlight semi-annually if storing it for prolonged time." This indicates some parasitic drain is expected. Hopefully the cell or light has low-voltage protection that will prevent the battery from over-discharging when in storage.



Low Voltage Battery Protection
The power switch can be half-pressed when off to read out the battery voltage, but after powering off due to low battery, the Concept 2 would indicate any voltage. After a few seconds on the charger, the internal meter would indicate 2.8V. Thus, low voltage cutoff appears to be about 2.8V.


Impact Resistance
Nitecore rates the Concept 2's impact resistance at only 1 meter. This was not tested.


Water Resistance
Nitecore rates the water resistance at 2 meters, though there is a note in the manual that cautions "Do not submerge the light into liquid when it is hot or attempt to use any liquid to cool down the light. Doing so may cause irreparable damage to the light due to the difference of air pressure inside and outside of the tube." Water resistance was not tested.


Internal Recharging
The Concept 2 comes with an AC charging adapter with a round connector. While micro USB would be more common/interchangeable, the specific AC adapter ensures the Concept 2 can get the required amperage to charge. Nitecore says a fully charged battery should take 5 hours to charge. The side switch blinks when charging and remains solid once charging is complete.



Outdoor Beamshots

All photos taken with a Canon SD4000IS camera. 1/4" exposure, ISO800, Daylight white balance, F2.0. Approximate distances: White deck railing @ 15 ft., white fence in distance @ 75 ft, back of dock @110 ft. Partial moonlight.


Control:
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Ultralow:
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Low:
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Medium:
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High:
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Turbo:
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Note: Turbo seems over-exposed but is just very bright. A person's eyes would adjust to eliminate this effect, but identical camera settings were left in place to show the progression from Ultralow to Turbo.



Interface


The Concept 2 has a complicated but feature-rich interface via its single dual-stage side switch.

From off:
  • Half press to perform battery voltage check
  • Half press and hold to perform lockout
    • Full press and hold to exit lockout
  • Full press to turn on
  • Full press and hold for momentary Turbo

From on:
  • Half press to cycle upward through output levels
  • Half press and hold for momentary Turbo
  • Full press to turn off
  • Full press and hold to access special modes
    • Half press to cycle through Beacon, SOS, and Strobe
    • Full press and hold to return to normal modes




Problems

No problems were experienced with the Nitecore Concept 1 while testing.



Commentary

The Concept 2 is incredibly bright given its small size. The output is at or near the top of the Nitecore hierarchy, and compared gram for gram, I can't think of any other stock light on the market that hits 6000+ lumens at this weight. Temperature regulation reduces output to protect the light but this also results in strong runtimes for Turbo and High – though Medium does fall a little short on runtime.

As far as modes spacing is concerned, the jump from Ultralow to Low is significant (1.6 to 306 lumens as tested) but the other modes have a good linear feel. Direct access to Turbo (whether on or off) is useful for times when a short but bright burst is needed.

The square body is comfortable to hold and while it gets hot on Turbo and High, it never got uncomfortable for me. The lanyard helps keep the light from getting away and the included holster can be used when carrying the Concept 2 in storage. The built-in battery indicator is accurate to 0.1V, helping the user know just how much battery is remaining. Many Nitecore lights display 1, 2, or 3 flashes based on charge level; the more precise readout found in the Concept 2 is appreciated.

The cool tint will not be to everyone's liking – though I found the hotspot was more neutral than cool. The shorter-than-typical 2 year warranty should be noted, as should the 1m impact resistance rating.

Overall I'm impressed with what Nitecore has achieved with the Concept 2: 6000+ lumens, 400 meters of throw, and many advanced features in such a small package.



Lux Meter: Dr. Meter LX1330B
Integrating "sphere": Homebuilt tube-style device calibrated on other known lights and test results. Numbers should be considered relative to each other and my other review figures but accuracy is in no way certified or guaranteed.

Camera: Canon SD4000IS
Micrometer: Mitutoyo CD-6ASX
Multimeter: Craftsman 82170


 
Last edited:

mcfarlie6996

Newly Enlightened
Joined
Jul 30, 2014
Messages
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Location
Phoenix, AZ
You mention:

Given the 12400mAh battery capacity, I would theorize that the Concept 2 actually has four 3100mAh 18650 cells inside.

But then talk about using Nitecore 3400mAh:

Note: The internal 12400mAh battery was used for all tests. I tested with a Nitecore 3400mAh NL1834 18650.

And then go on to say you tested with 30Q:

Tests were repeated with a custom Samsung 30Q button-top battery to see if the lower resistance battery would produce improved results. Turbo was indeed higher at 1060 lumens; Moonlight was unchanged.

Are these typos or did you take the light apart and use these other batteries.

"Turbo was indeed higher at 1060 lumens" also seems like it wasn't meant to be there. Possibly from a previous review?
 

Bdm82

Flashlight Enthusiast
Joined
May 27, 2016
Messages
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Location
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You mention:



But then talk about using Nitecore 3400mAh:



And then go on to say you tested with 30Q:



Are these typos or did you take the light apart and use these other batteries.

"Turbo was indeed higher at 1060 lumens" also seems like it wasn't meant to be there. Possibly from a previous review?

First of all, thank you for catching these. Definitely an error on my part, now corrected.
 

lumen aeternum

Enlightened
Joined
Sep 29, 2012
Messages
890
Now if they would just make the max output an honest 1000 Lm, with several lesser modes, it would be pretty good.

In real use, people will turn the light onto its highest output. Or they will miscount and goto high when they mean to use the hours-long setting. Since the eyes cannot tell the difference. The result is draining the battery when they really need the long runtime.
 
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