[Review] Nitecore Concept 2 (6500 Lumens, 39700 cd, 398m, 4xCREE XHP-35 HD, 4x18650 Built-in Rechargeable Battery Pack)

Hello to everyone
Thanking them for the trust, today we will review the Nitecore Concept 2 which was kindly provided by Nitecore itself.

CLICK HERE to go to the official product page on the Nitecore website.

I want to clarify that my reviews are made at an amateur level, so without the aid of science fiction tools or tests in secret laboratories and cutting edge. Therefore, among the lines that follow, there will be my humble observations and even my humble opinions.

Official features:

- futuristic ultra-bright palm-sized flashlight
- utilizes 4 CREE XHP-35 HD LEDs with a max output of up to 6500 lumens
- beam intensity up to 39700 cd and beam distance up to 398 meters
- CNC machined tube features lightweight, solidness and excellent heat dissipation
- built-in 12400 mAh Li-Ion battery with high rate discharge
- onboard intelligent charging circuit
- crystal coating technology combined with "Precision Digital Optics Technology" for unparalleled reflector performance
- high efficiency constant circuit provides unwavering output up to 2000 hours
- single switch controls 5 brightness levels and 3 special modes
- intelligent memory function
- integrated power indicator light displays remaining battery power (Patent, No. ZL201220057767.4)
- power indicator displays battery voltage (accurate to ± 0,1V)
- Advance Temperature Regulation module
- toughened ultra-clear mineral glass with anti-reflective coating
- constructed from aero grade aluminum alloy with HAIII military grade hard-anodized finish
- waterproof in accordance to IP68 (2m submersible)
- impact resistant to 1 meter

Where to buy it

Nitecore Concept 2 could be purchased from NitecoreStore.com

The package and the accessories

The Nitecore Concept 2 is sold inside an elegant (and at the same time minimal) black rectangular box made of very strong cardboard.
On the front, instead of a photo of the product, we find the design of the flashlight in slightly larger dimensions compared to the actual product. Immediately below the design, written in large, we find the maximum lumens generated by this new Nitecore flashlight: 6500 lumens!
Then there is the product name and the Nitecore logo.

On the back, in an orderly manner, we find the essential characteristics of the product, the company data, the summary drawings with the relevant data, the CE and RoHS certifications and a QR-code that directs the product page on the website of the Nitecore .

There is no information on the long sides, while the word "Concept Series" is found on the short sides. On one of these two sides there is also a sticker with the product name, the information on the LEDs used, a barcode and the product identification number.

Once the package is opened, we will find:

- the Concept 2
- 4 x 18650 (inserted inside the flashlight and not removable)
- the wrist strap (already attached to the flashlight)
- the wall charger with European/Country-type socket, power jack and cable a little less than 1 m and 20 cm long
- a small switch and a spare silicone cap
- Cordura sheath
- the warranty card
- the multi-language manual

The sheath supplied in the package is made in cordura. The opening is entrusted, as always, to the velcro.

On the back we find a plastic D-ring, a belt loop and a loop with Velcro to attach the sheath to a MOLLE system.

Due the shape of the flashlight, it can be inserted inside the sheath both with the head up or down and the presence of the lanyard does not create any problem.
It should be noted that, on the side, the scabbard has a continuation of the velcro. On one side there is also the flap with the company logo.

Here is the manual in the English and Italian languages. Alternatively, it can be viewed in full and / or downloaded from the Nitecore website by clicking HERE .

The flashlightes

Concept 2 is one of the latest flashlightes born in Nitecore house. It boasts a very compact body despite guests in its inside 4x18650 batteries. The flashlight stands out for its particular shape. In fact, it is a parallelepiped with rounded corners, it is impossible for it to roll away somewhere.
The aluminum alloy body, excluding the head and tail, is obtained from a solid block thanks to the CNC. The anodization present is perfect.
In the upper part there are small carvings that improve the dissipation and on the body the bevel is more evident. It is used to guarantee a more comfortable grip if the end user does not have large hands.
Since it has 4 sides, there is a different element on each one. On this side we find the switch that controls the UI and the Nitecore logo with its website,

on the other side there is the name of the product flanked by the certifications,

on the other side there is the clip

(it has a good grip on the "summer" clothes and excellent on the slightly thicker ones)

and, on the last one, there is the battery charging port,

obviously covered by a removable silicone stopper thanks to a practical tongue. Immediately above the cap is the product identification code.

And here is the door uncovered. With the plug inserted the flashlight has, according to the specifications, a protection against water and dust according to the IP68 standard.

On the opposite side of the port there is the only flashlight switch . This switch has a dual function: a bit like the shutter keys of the cameras, you can in fact perform both a half-pressure (TAP) and a complete pressure. In the appropriate section we will see how to take advantage of this feature.
The TAP will not emit any sound while, with full pressure, you will have an average noisy click.
A blue indicator light is also located under the switch .
Unfailing is the usual design that warns us about the danger of high temperature (and at the Turbo level it rises very quickly). The lettering of this and all other written information is perfect.

Looking at the switch from its side, you can see how it protrudes from the flashlight body. This makes its detection in the dark very easy.

Interacting with the switch will turn on the 4 x CREE XHP-35 HD LEDs with the CW tint (slightly brownish at low levels and pure in the highs). The LEDs are inserted in 4 small SMO parabolas, partially fused together.

The lens (made of tempered mineral glass) that overhangs the whole has anti-reflective treatment (although it is very difficult to see) and is held in place by a bezel that could be removed by unscrewing the 4 hexagonal screws, but it is an operation that I do not recommend to avoid invalidating the warranty.

On the opposite side of the head there is obviously the tail, also fixed to the body with 4 hexagonal screws that should not be touched. One of the 4 screws, among other things, has the task of keep fixed the clip.

The bottom of the flashlight is completely flat so facilitates us if we put the flashlight in the tail-stand and, thanks to the large surface available, in this position the flashlight is beautifully stable.
In one of the 4 corners of the tail there is the small hole that allows us to attach the wrist lanyard, lanyard that does not affect the tail stand.

The battery pack and the charging system

Concept 2 has integrated a 12400 mAh (and 3.7 v) built-in Li-Ion battery pack consisting of 4 x 18650 which has 3100 mAh each and that are arranged in parallel. As soon as I received the flashlight, the battery pack had a voltage of 4.1V (voltage measured with the built-in "multimeter").
Officially, in order not to invalidate the warranty, the flashlight can not be disassembled and therefore, to load the battery pack, we should take advantage of the charger in the package.
It is made up of a transformer with a European/country-type bipolar plug (because my product is destined for the European market), a cable a little less than 1 m and 20 cm long and a plug.

The transformer, model JKY0212-1201000EU, has an output of 12V and 1000 mA (1A).

The plug must obviously be inserted into the flashlight to start charging. The blue indicator under the switch will start to flash to let you know that the process has started

and it will remain lit permanently to alert you that the flashlight is charged. The whole process, starting with the completely discharged battery pack, will take about 5 hours to reach 100%.

How does it work

Concept 2 has eight selectable levels, three of which are special levels (Strobo, Beacon, SOS).

According to official Nitecore data, normal levels have the following characteristics:

- Turbo -> 6500 lumens for 30 minutes *
- High -> 2500 lumens for 1 hour and 30 minutes *
- Mid -> 1000 lumens for 3 hours and 30 minutes
- Low -> 285 lumens for 16 hours
- Ultralow -> 1 lumen for 2000 hours

Each special level (Strobo, Beacon, SOS) will use all 6500 lumens available to operate .

WN The declared durations have been recorded in the laboratory by Nitecore with the 12400 mAh built-in battery pack, obviously fully charged.
* this duration was reached by adding the duration of the level in question before the intervention of the ATR.

Before reading how operate the flashlight, remember that the switch on Concept 2 is a double stroke switch. It can be pressed in half (TAP) or it can be pressed completely (up to the end of stroke).

Power On / Off

With a single full click of the switch (with the flashlight unlocked, of course), we will turn the flashlight on or off. Due the presence of memory, the last level previously used will always be repeated.
WN Special levels are not remembered from memory.

Change levels

With the flashlight turned on, a single switch TAP will be enough to cycle all the available normal levels in ascending order. Obviously 1 TAP = 1 change level.

Quick access to the turbo

With the flashlight turned on, and at any level, you can quickly recall the Turbo keeping the switch tapped. If you stop the pressure, it will return to the previous level.
With the flashlight turned off, you must press and hold the switch until end of stroke. Interrupting the pressure, in this case, will turn off the flashlight.

Special levels

As written at the beginning of the paragraph, the flashlight includes 3 special levels: the Strobo, the Beacon and the SOS.
These levels can be selected only when the flashlight is turned on by performing a complete and prolonged pressure on the switch .
In this way we will immediately access the Strobo level and, as for normal levels, with 1 TAP of the switch, the special levels will also cycle (will follow the order written above).
In case of an emergency, it is possible to switch from the Beacon and / or SOS level to the Strobo level by performing a prolonged TAP of the switch .
WN To exit the special levels, the flashlight must be switched off by performing a single full pressure on the switch .

Lock / Unlock

Due the impossibility of performing a physical lock-out on the flashlight and due the ease with which the flashlight could be accidentally lit, the Concept 2 is equipped with an electronic Lock-out. Nitecore herself recommends using this block whenever we have to carry the flashlight.
The block can be switched on when the flashlight is turned off by tapping the power switch for 2 seconds. The LEDs will perform 1 rapid flash to let us know if the block has occurred.
The unlock is made by keeping the switch pressed completely for 2 seconds. The LEDs will light up when we have unlocked the flashlight.

Charge indicator

With Concept 2 it is possible to know, in a precise way (with a margin of error of ± 0.1 V), the remaining charge of the battery.
When the flashlight is turned off, it will be sufficient to perform a TAP on the switch, in this way the indicator below it will start blinking followed by a pause followed by other flashes.
For example, if we have a voltage of 4.2 V, we will have 4 flashes, pause and then another 2 flashes; with 3.8 V, we will have 3 flashes, pause and then another 8 flashes.
As you can see from the examples, the system is as simple as it is ingenious. It's like having a multimeter inside the flashlight.

ATR system

This is the Nitecore system to adjust the light output of the highest level of the flashlight depending on the outside temperature. The more the conditions are favorable to the flashlight (low temperatures / fresh wind) and more, the higher levels, will emit light.

Dimensions: weights and dimensions

The Nitecore Concept 2 measures 11.22 x 4 x 4 cm. It weighs 348 gr.

Next here is the dimensional comparison with a big BIC lighter and a 18650,

with the Concept 1 (1x18650)

and with the Rofis MR70 (1x26650). It is amazing to see how the two flashlightes, although they have 2 completely different powers, are very similar in size.

Lumens, runtimes, candles and beamshot

NB The tests below were made with the battery pack built-in into the flashlight. Everything was done in a home environment at 26 ° with and without forced ventilation.

The following values have been taken with the charged battery pack and are considered to be peak .

The following values have been taken with the charged battery pack and are considered to be peak .

NB The discharge curves are obviously indicative, the result could vary in positive or negative depending on the batteries used by the end user or the conditions of use that may vary from mine during my tests.

Any slight discrepancies related to the tests carried out on the same level can be attributed to a different positioning of the measuring equipment in my tests.

The following values have been taken with the charged battery pack and are considered to be peak .

All the following photos were taken with the white balance set to 5200K.

This photo was taken at a distance of 40 cm from the wall.

Beam width

Beamshot at the Turbo, High, Mid and Low levels. The tree line is 25 meters away. The spill, with the spot facing the infinity on the horizontal plane, starts from about 80/90 cm from my feet.

The house is 70 meters away and I used the same levels as before.

The trees at the bottom are about 150 meters away. I have always used the same 4 levels used before.

I also take this opportunity to attach a short video that makes the idea of the potential of the flashlight better.


Personal considerations

"Futuristic ultra-bright palm-sized flashlight!", these are the words used by Nitecore to describe its product. The name of the model itself, Concept, makes us understand that we will be faced with a model that deviates from the canonical models that we are used to seeing.
In fact we will find ourselves in front of a product with a square body, compact size (if you think that hosts a built-in 4 x 18650 batteries' pack, and the great power, released by the 4 LEDs capable of delivering 6500 lumens.

To be honest, seeing the first online photos of this flashlight, I was afraid that it would not be easy to hold because of its particular shape. But, after handling it for a while, I can say that due to its rounded corners it is comfortable to grip even for those who, like me, do not have particularly large hands.

The switch is easily localisable, the UI is intuitive and easy to learn. The levels are correct, but an intermediate level could be inserted between the 1000 lumens and the 285 lumens level.

With the High and Turbo levels you have 2,500 and 6500 lumens respectively, lots of light ... and heat. In fact, the low dissipating mass is the limit of this flashlight that must quickly dispose of the high heat produced by the Turbo. In the discharge curves it is easy to see that, with this level, the flashlight performs a step down and then adjusts itself in the best possible way thanks to the ATR.
In my opinion, however, we must frame this level in the right perspective: it must be used in situations of real necessity, perhaps taking advantage of the "Momentary-ON" by holding (or keep tapped) the switch.

After all I have not found any faults. But, to split hairs, I would say that the indicator under the button could be slightly brighter (in the dark is perfect but in the day, if there is a lot of light, you see it only a little) and the tongue of the plug that protects the charging port could be a little longer (I, which have the bad habit of eating my nails, sometimes I found difficult to open it. My friend instead had no problems to open it).

What do you think of this Concept 2? Would you buy it?

Thanks for the review! :smiley: