NEXTORCH K40

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NEXTORCH K40specifications

Brand & Model	NEXTORCH K40
Flashlight category	keychain flashlight
LED	N/A
Max. output	300 lumens
Max. beam distance	78 meters
Max. beam intensity	1520 cd
Battery config.	Built-in
Onboard charging	USB-C
Modes	3
Blinkies	Strobe
Waterproof	IPX4
Review publication date	February 2023

I was first introduced to NEXTORCH a little over a year ago when I had the opportunity to review one of their LEPs, the L10 Max. I went into that review unsure of what I would find. I’m pleased to say that NEXTORCH made a good first impression. Their new flashlight that’s up for review is an entirely different specimen, a keychain model named K40. The K40 features a main white LED plus 3 auxiliary LEDs in UV, red, and blue. As you’d expect from a keychain light, the NEXTORCH K40 is small and light, but it’s also feature-packed. Let’s unpack it!

Package quality.

The NEXTORCH K40 came in a fairly nice looking presentation carton that would be at home on a store shelf or display. The outside of the box has a nice picture of the light, along with just enough information to pique one’s interest. Opening the box, you’ll find a clear plastic tray with the goodies packed in:

• NEXTORCH K40
• Charging cable
• Keychain clasp
• Manual

The K40 is a slim, sleek little thing, if perhaps a bit slippery due to the glossy polycarbonate construction. The body includes a largish ring that protrudes from the tail that serves as an attachment point. In general, the design of this NEXTORCH reminds me of several keychain lights that you’ll find on the market – a design that seems to have been pioneered by Rovyvon. Unlike those lights, though, the clip on the K40 seems more integrated into the body of the light. In fact, I think the clip is non-removable – at least it seems to be firmly stuck to the light. The stout clip is oriented for a head-up carry, which is also the position you’d want it in if you’re going to put it on the brim of a hat for a makeshift headlamp.

As far as using the NEXTORCH K40 goes, this is a keychain light – so keep your expectations in check. It boasts 300 lumens in a small package, so it’s good for either short bursts of bright light (like navigating to your car or door) or longer running low-light tasks (like reading a book).

Like some of those other keychain lights, the K40 features a few side-firing auxiliary LEDs. There are red, blue, and 405nm UV LEDs. The red LED can be used on its own and is good for illuminating things at night without killing your night vision or potentially disturbing nearby wildlife. The blue LED can only be used in conjunction with the red LED in a flashing pattern which is not too dissimilar from the lights of a cop car. I’d urge caution when using that mode – at least in my state (Illinois), using flashing red & blue lights is a good way to land yourself with a felony charge.

Lastly, the UV light could potentially be useful for the identification of certain minerals, stains, or anti-counterfeit measures. A bit unfortunate is the wavelength that was used: 405nm. That wavelength was probably necessary to be able to shine through the polycarbonate body since PC blocks most UV light. Generally speaking, 365-385nm does in several applications, especially when inspecting US currency for anti-counterfeit markings. Using the K40, I was able to pick up the UV strip on $5, $10, and $20 bills – but it was very faint.

The body of the NEXTORCH K40 is constructed of clear, glossy polycarbonate – like what you’d see in safety glasses and such. The clear body lets you see all of the inner workings of the light and it looks pretty slick. The bezel of the light is made from aluminum with a black coating. The aluminum is a bit tougher of a material and helps with some heat dissipation. Overall, the build quality seems nice and well put together. No complaints here.

Warranty:

• NEXTORCH offers a 5-year warranty
• NEXTORCH warrants our products to be free from any defects in workmanship and / or material, we will replace or return faulty item. NEXTORCH reserves the right to replace similar products if original one is discontinued.
• The warranty excludes other accessories, but rechargeable batteries are warranted for 1 year from the date of purchase.
• Any accessories or products are not covered in the warranty, NEXTORCH can repair for users with reasonable fee.

What LED is within the K40 is a mystery. NEXTORCH hasn’t divulged that information, and it’s a bit tough to tell through the optic. I do see that the “mouse bites” from the bond wires are actually in the middle of opposing sides of the LED, which is a bit distinctive, but unlike any LED that I’m familiar with. The main LED sits below a clear TIR optic. The optic provides a relatively smooth, broad beam which my eyes interpret as definitely in the cool-white arena and a touch bluish.

Opple Light Master readings from High at 3m:

• CCT: 6556K
• CRI: 73.3 Ra
• DUV: +0.0004

Dimensions: 

NEXTORCH K40	Millimeters	Inches
Length	73 mm	2.9 in
Head diameter	17 mm	0.7 in
Body diameter	17 mm	0.7 in

Dimensions are rounded to the nearest millimeter, and to the nearest tenth of an Inch.

Weight: 

NEXTORCH K40	Weight in grams	Weight in oz
With battery	17 g	0.6 oz

Weight is rounded to the nearest gram, and to the nearest tenth of an Oz.

Flashlight size comparison with its competition:

Group 1: Rovyvon A8 G3, NEXTORCH K40, RovyVon E7

Group 2: Wuben G2, NEXTORCH K40

Group 3: Skilhunt E3A, Olight i3E EOS, NEXTORCH K40, ThruNite Ti3 V2, Jetbeam Jet-U, Sofirn C01

Available modes: 

• Low, Medium, High, Red, UV

Available blinky modes:

• Strobe, Red & Blue Flash
  

The NEXTORCH K40 has a dual-switch setup. There are 2 e-switches near the head. NEXTORCH hasn’t given them names, so I’ll just refer to them as the front switch and rear switch.

From OFF:

• Front switch, Single click: High mode
• Rear switch, Single click: Strobe mode
• Rear switch, Press and Hold 1 sec: UV mode

From White Light ON:

• Front switch, Single click within 3 seconds of last press: next mode (High > Med > Low) 
• Front switch, Single click after 3+ seconds of last press: turn Off
• Rear switch, Single click: Strobe mode 

From Aux Light ON:

• Rear switch, Single click: change aux modes (UV > Red > Red & Blue Flash)
• Rear switch, Press and Hold: turn aux Off

Mode memory:

• There is no mode memory

Shortcuts:

• To High: single click from switch (from Off)
• To Strobe: single click rear switch (from Off or On)

Low voltage warning:

• There is an indicator LED between the switches that indicates the battery level:
  • Blue light: 70% – 100%
  • Blue flash: 50% – 75%
  • Red light: 25% – 50%
  • Red flash: 0% – 25%

Strobe/blinkies

• Single click the rear switch (from either Off or On) to activate Strobe

Lock-out mode: 

• None

PWM

• There is 15.7 kHz PWM

Additional/summary info on the UI: 

• The main LED and Aux LEDs can be operated independently of each other and simultaneously. That is, with the White LED on, you can press & hold the rear switch to activate the Aux LEDs. Or with the Aux LEDs on, you can click the front switch to activate the White LED.

The NEXTORCH K40 utilizes a built-in 180 mAh LiPo battery. It is not user-serviceable, but that’s pretty typical for little keychain lights like this. The battery is charged via USB-C, with the port residing under a little rubber plug towards the tail of the light. NEXTORCH says that charging should take around 1.5 hours. That’s pretty accurate. In my testing, I observed a 0.92 watt charge rate (0.18 amps @ 5.3 volts). The charge cycle was done in 1 hour and 20 minutes, transferring 1.1 Wh of power.

Lux was measured by a UNI-T UT383 BT at 5 meters. Lumens were measured in a homemade lumen tube using a VEML7700 sensor, calibrated with a Maukka calibration light.

Lumen measurements (for each mode)

Mode	Specified	turn on	30 sec	10 minutes
Low	10 lm	7.9 lm	7.9 lm	7.9 lm
Med	50 lm	29 lm	29 lm	27 lm
High	300 lm	340 lm	310 lm	76 lm

Parasitic drain:

• Not measurable due to internal battery design 

For the most part, my output measurements meet the specs. Medium mode seemed a bit under-spec, but I’m mostly concerned with the highest mode attaining its claim.

Battery Life: Runtime graphs

Mode	Specified	Measured runtime ANSI	Time till shut off
Low	9h 15min	9h 20min+	9h 20min+
Med	1h 30min	1h 55min	1h 57min+
High	1h	1h 3min	1h 13min+

NEXTORCH’s runtime claims seem pretty spot-on. I cut the tests short because the light continued to chug along for hours, slowly decreasing as it went.

About ANSI FL1 standards: The runtime is measured until the light drops to 10% of its initial output (30 seconds after turning on). This does not mean that the flashlight is not usable anymore. The last column shows how long the light actually works till it shuts off. If there is a + symbol, it means that the test was stopped at that particular point, but the light was actually still running. This happens on certain occasions, with certain drivers, firmware, or batteries.

Peak beam intensity and beam distance measurements

Intensity was measured at 5 meters after being turned on for 30 seconds. A UNI-T UT383 BT lux meter was used.

Mode	Specified	Candela measured	Meters	Yards
Low	40 cd	–	–	–
Medium	232 cd	300	35 m	38 yd
High	1520 cd	1700	82 m	90 yd

Just like in the lumen and longevity tests, the intensity seems right inline with specs. It’s nice to see some accurate numbers.

About peak beam intensity: Peak beam distance according to ANSI FL1 standards: The calculated value of distance in meters at which the flashlight produces a light intensity of 0.25 lux. (0.25 lux is about the brightness of a full moon shining on an object). The columns ‘Meters’ and ‘Yards’ use rounded numbers.

Camera settings and distance: 

Beam shots of the building are taken at 5 m (33 yd) using a Pixel 7 set to ISO 800 with 1/30 second exposure time

Beamshots of the following flashlights compared:

• NEXTORCH K40
• Rovyvon A8 G3
• Wuben G2

Disclaimer: This flashlight was sent to me for review at no cost by NEXTORCH. I have not been paid to review, nor have I been holding back on problems or defects.