Nitecore UT27

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Nitecore UT27 Review: Headlamp for jogging

Nitecore UT27 specifications

Brand/modelNitecore UT27
LEDCREE XP-G S3 3000K + 5700K
Lumens200+400+520 lm
Beam intensity4,120 cd
Battery config.1*HLB1300 battery / 3*AAA
BlinkiesFlashing red
Review dateDecember 2021


If you’re a lumen addict and looking for a headlamp, the UT27 is probably not for you. But if you’re into jogging for several hours, you better pay attention. Because t first sight, the UT27 looks a little boring, but I soon realized that the UT27 is built with a specific application in mind, namely trail running/jogging. Tailor-made for Train Runner is what Nitecore’s website says.

They build an extremely lightweight headlamp to reduce the annoyance of something bumping up and down on your forehead. And that’s one reason why I was so interested in this one. Because having a headlamp is one, having a headlamp that is plenty bright, has long runtimes, is lightweight, is yet another.

If you’re more into T-shaped headlamps, don’t forget to check out the Nitecore HC65 v2 we just reviewed.

Package quality.

The packaging is retail-friendly with a hung tag and a transparent window so you can see the headlamp on the inside. Inside the package, you can find the following:

  • The headlamp: Nitecore UT27
  • USB-A to USB-C cable
  • 2* HLB1300 batteries (1300mAh)
  • Pouch
  • Warranty card, operation diagram, and manual

Keep in mind that this headlamp was designed for jogging and trail running. Nitecore included 2 batteries to ensure you won’t be out of light (and luck) on the trails. The shortest runtime, according to the specifications, is 6 hours. So you’re looking at a total of 12 hours in the highest setting and many more hours in lower outputs.

Headlamp in use

First of all, this thing is very lightweight. And not the type of lightweight you find in cheap dollar store headlamps, but a high-quality headlamp built to last.

The strap is adjustable, and I found some interesting details that you usually wouldn’t think of. First of all, the buckle that you can use to adjust the strap has some protrusions on top. This gives you more grip to pull the band tighter. A nice little detail!

There is another interesting detail, and I’m not sure if Nitecore did that on purpose. But the reflective letters (NITECORE) feel rubbery and are stuck on top of the band, so to speak. So if you adjust the band, these rubber letters will help keep the buckle in place! This way, the size won’t change during the race.

And last but not least, the headband has many tiny holes, to make it ‘breathable’.

Nitecore used 2 kinds of letters on the headband. The typical yellow letters and the reflective silver letters.

The inside of the band has a silicone (or rubber) strip about 5mm wide and about 20 cm long, covering your entire forehead. This is another way to keep the headlamp in the correct position.

The battery compartment and light are 1 piece. Sometimes the headlamp battery is located on the rear, but with the UT27, the battery is placed right behind the light source. While running, this is probably the most accessible position to replace the battery. Also, just for the extra usefulness, the battery compartment has a (GITD) glow in the dark finish, so you can still see how to insert your spare battery (or 3*AAA batteries in case of an emergency).

And if you think this is the last great feature, you’re wrong. Did you see the white pouch? Well, besides using this to store your headlamp or spare battery, it can be used as a diffuser! Lol.. yes.. I love the fact that Nitecore paid so much attention to designing and building this.

To operate, you have 2 buttons on top of the light. One is labeled with the letter W, and the other with a T. W is probably standing for Wide, and I don’t know what the T stands for, but I imagine it be be Throw?

A single press on either of the switches will only show a red light blinking. This is a battery level indicator. I will talk more about that in the UI section of this review.

Build Quality, and Warranty

Yes, it is made of plastic, and yes, that does look a bit weak. But no, it’s not that weak, and no, it’s not cheap plastic.

I already explained about the headband and the battery compartment above, but the flashlight is lightweight, and seems to be made of good quality materials.

As far as warranty goes, Nitecore has your back with three levels of guarantee:

  • Exchange and DOA/defective products locally within 15 days of purchase
  • Defective / malfunctioning products will be repaired free of charge for 60 months
  • Beyond 60 months, Nitecore will cover the cost of the labor and the end user is responsible for the cost of the parts

LED, Lens, Bezel, Beam, and Reflector

The UT27 uses 2 different main LEDs. Both of them are CREE XPG S3 LEDs, but they aren’t the same color temperature. The one used for throw is warm white (3000K) and the one for flood is cold white (5700K)

Spot and flood are 2 different switches, so you don’t have to do X number of clicks to switch between flood and throw (cold and warm). If you wear the headlamp, the left switch is for the wide (cold) beam, and the right switch for throw (warm) beam.

I’m not sure why they choose the warmer CCT LED for throw. Maybe because cold white hurts your eyes more on the trail?

Here are the measurements I got with the Opple Lightmaster III

Spot (throw, cool white)

  • CCT: 5950K
  • CRI (Ra): 71.1

Wide (flood, warm white)

  • CCT: 3080
  • CRI (Ra): 66.4

This means that both LEDs are low CRI, but for most people, that’s not an issue.

The wide beam is very pleasant to use because it doesn’t have a clear hotspot, so the surroundings look great. You don’t get blinded by the middle (hotspot) of the beam. Throw mode is a warm white LED that has a more distinct centered beam. And in Turbo it’s a mix of Wide/flood and Throw, but not max of both. It’s a combination of both, but somehow not the highest setting of each mode. It’s less bright than High and doesn’t throw as far as High.

Dimensions and size comparison

  • Side to side diameter: 55.4 mm / 2.18 ”
  • Thickness: 22.46mm / 0.88 “


  • Headstrap only: 20.9 g / 0.74 oz
  • Empty headlamp only: 26.7 g / 0.94 oz
  • Empty headlamp with headstrap: 47.7 g / 1.68 oz
  • Everything with HLB1300 battery: 73.3 g / 2.59 oz
  • Everything with 3*Eneloops: 83.4 g / 2.94 oz

The HLB1300 battery pack makes the headlamp 10 grams lighter than 3*Eneloop batteries, and also increases battery life. So it’s much better to use the HLB1300 battery pack than 3 AAA batteries.

Nitecore Headlamp comparison

Size compared to the Nitecore HC65v2 headlamp. The UT27 is lying upside down.

Driver & User Interface:

When you are running on a trail at night, you don’t want to make mistakes and accidentally hit a hidden mode. Nitecore incorporated therefore 2 separate switches. If you are wearing the headlamp: the left is for Wide (flood) and the right is for Throw. And although most people don’t like a long-press for ON (and especially for OFF), I can totally understand the reason they chose for this. Again, if you’re jogging at night, you don’t want to accidentally turn your light off, and you only need to press briefly to change modes. You don’t want to run and keep pressing that stupid switch for 3 seconds while ramping up from Low to High etc..

Available modes:

  • Throw: high, low
  • Flood: high, low
  • Red: on, blinking
  • Turbo momentary: accessible from all modes, including RED: Turbo works for only 30 seconds

From OFF:

  • Single-click either switch: battery level indicator
  • Double click: red-constant (and a single click to switch between red-constant and red-blinking) and another double click Turbo mode both white LEDs for 30 seconds.
  • Triple-click: nothing
  • Press and hold: On (either switch)

From ON:

  • Single-click: change between output modes, you can change from throw to flood, and visa versa.
  • Double click: Turbo
  • Triple-click: nothing
  • Press and hold: Off


  • To Turbo: double click when on

Mode memory:

  • No

Blinky modes menu:

  • Only red blinking

Low battery warning:

  • There is no real warning, except that the output will greatly be reduced. At that point it’s better to replace the battery/batteries.

Lock-out mode:

  • Press both switches for 2 seconds simultaneously


  • Not visible!

Batteries & Charging

The headlamp itself doesn’t have onboard charging. And that’s done on purpose of course. This light is designed for long trail tracks, so it’s useless to have onboard charging.

Instead of onboard charging, the battery packs Nicecore included are rechargeable. They are Li-ion batteries with a total capacity of 1300mAh and are labeled Nitecore HLB1300. Nitecore also included a USB-A to USB-C cord for charging. It also works with USB-C to USB-C charging, in case you’d prefer that. But it doesn’t have any benefits in terms of charging speed, because they are the same.

It takes 1.5 hours to charge, and there’s a red indicator that is visible during charging. The light will turn green when the battery is finished charging. Max current is 1A, at 5 Volts. After the runtime test, the battery Voltage is 3V, which is pretty safe.

For backup, you can also replace these battery packs with 3*AAA batteries. Keep in mind that this will have a reduced runtime, and output, especially if you are using low-quality Alkaline batteries. I’d recommend using the included battery packs as much as you can and staying away from Alkaline batteries. If you want to use AAA batteries, make sure you get the best rechargeable batteries available, and those are Panasonic Eneloops.

It wasn’t until I was about to publish the review that I noticed that the hinges of the battery door were broken! That’s not really good, and I have no idea how that happened. Maybe I was a little too rough on opening it? I probably opened it about 20-30 times, replacing batteries for testing.


Lumen measurements:

All output numbers are relative to my homemade Integrating Sphere. It is set up with an Extech SDL400 Lux Meter for measurements including a Kenko PRO1D ND-16 filter. The base measurement is done with a Convoy S2+ that has been tested at 255 lumens.

For Amp readings, I use a Fluke 77III DMM. For higher amps I now use a Fluke 325 True RMS clamp meter. For microamps, I use a cheap DMM with an easy-to-use micro amp setting.

All of my readings were taken from a fully-charged Nitecore HLB1300 battery with 1300mAh

ModeSpecs@ turn on@ 30sec@ 10 min
Spot Low100112111110
Spot High400 lm468442 lm247
Wide Low55565555
Wide High200 lm245241 lm222
Turbo520 lm585 lm564 lm

My measurements were a bit higher than specs. But it’s clearly not one of the brightest headlamps out there.

Here are the measurements with 3AAA Eneloop batteries

ModeSpecs@turn on@30sec@10min
Spot low100 lm112112111
Spot High400 lm 475445 lm252
Wide Low55 lm565554
Wide High200 lm251246 lm228
Turbo520 lm608580 lm

I don’t know how come, but Turbo, and the highest modes are brighter on Eneloops than the included lithium-ion batteries.

Parasitic drain:

  • I couldn’t measure because of the setup.


The runtime test was done with the 50cm integrating sphere, including the Kenko Pro1D ND-16 filter and Extech SDL400 data logging Lux Meter.

Runtimes with Nitecore HLB1300 Lithium Ion

First runtime tests were done with the HLB1300 batteries

It’s interesting to see that all 4 modes have similar-looking endings.

Wide High: (blue line) starts at around 241 lumens and slowly drops till it reaches about 74 lumens at 53min. It continues till 9h0min when it drops down to 10 lumens. From 9h37min it slowly drops till it finally reads 0 lumens at 10h33min. (specs: 8h)

Wide Low: (red line) is very stable at 55 lumens for the first 5h26min. It then slowly decreases output 40 lumens at 5h32min. It then runs very stably till 16h33min when it slowly decreases output till it reaches 36 lumens at 16h43min when it drops down to 9 lumens. It slowly drops till it reads 0 lumens at 18h04min. (specs:13h)

Spot High: (yellow line) starts at 442 lumens and starts dropping in output right away. At 11minutes it’s down to 226lumens. It then continues dropping, but at a much slower rate till it reaches 90 lumens at 1h09min. It then runs stable at that output till 6h33min when it decreases again till 6h37min when it quickly drops to 10 lumens. It then slowly decreases till it reads 0 lumens at 7h49min. (specs: 6h)

Spot low: (green line) starts at 110 lumens and sustains that output to 40min. At this point, it starts to ramp down till it reaches 56 lumens at 0h56min. It maintains running at this output till 12h53min when the output drops to 10 lumens. At 13h38min the output starts to drop from 10 lumens down to 0 lumens at 14h13min. (specs:10h)

Runtimes with 3*AAA Eneloop batteries

I used the same time stamps, so you can compare it better to the runtime graph of the HLB1300 battery.

The runtime graph for the first hour looks identical, which is kind of interesting.

The full runtime graphs are pretty different though. I’ll not the total runtime (10% of initial output)

Wide High: (blue line) 4h42min (at this point it’s 10 lumens)

Wide Low: (red line) 9h18min (at this point it’s about 4 lumens)

Spot High: (yellow line) 2h47min (at this point it’s dropped from 86 lumens to 10 lumens)

Spot low: (green line) 7h18min (at this point it dropped from 51 to 10 lumens)

The total runtimes don’t mean that the light turned off, it only means they dropped to an output lower than 10% of the initial output.

Throw Measurement

Measurements were taken indoors at 5 meters with a professional Hagner E4-X Lux Meter. These were done 30 seconds after turn on.

ModeSpecsmeasure candelain metersin yards
Flood low66 cd (16m)75 cd1719
Flood high250 cd (31m)300 cd3538
Spot low1,060 cd (65m)850 cd5864
Spot high4120 cd (128m)3,250 cd114m125

My measurements were quite a bit lower than the specs.


For the following beamshots, I used a Canon EOS 5D Mk2 and a 50mm lens. manual settings: ISO1600, 1/4sec , F4, 5000K

The shed is about 65 meters / 71 yards away, and the reflective fence 200 meters.

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

Final Verdict


  1. Lightweight
  2. Great for intended purpose (jogging)
  3. No PWM
  4. Lightweight HLB1300 battery included
  5. Easy to replace batteries on the go
  6. Batteries have USB-C ports


  1. Output is relatively low compared to high power lights
  2. The hinges of the battery cover broke

Explanation on star ratings:

1: Avoid: my phone flashlight would be a better choice – 2: Poor: significant defect or issues; almost unusable – 3: Average: some defects or issues; but still usable 4: Good: recommended (minor issues) – 5: Great: highly recommended

Reviewer Marco
Author: Marco

3 stars: ★★★

I was about to rate it with 4.5-5 stars, until I noticed that the 2 hinges of the battery compartment cover were broken. I can’t remember I stressed them too much, so they might be a little too fragile. I’m not 100% sure how this happened, and I hope it’s just an incident. But for Nitecore this is something to look into.

Therefore I had to lower the overall score. If you are careful with those hinges, or if they upgrade them, this could be an excellent headlamp.

Nitecore UT27 For Sale

1lumen selects and reviews products personally. We may earn affiliate commissions through our links, which help support our testing.