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Nitecore UT27 Rechargeable Headlamp Review

Nitecore UT27 Rechargeable Headlamp Review

The Nitecore UT27 is a 520-lumen dual power headlamp with a rechargeable Lithium-ion battery that can also be powered by 3 AAA Alkaline or Ni-MH batteries. Designed for runners, it has a spotlight, floodlight, red, and turbo modes with an electronic lock to prevent accidental power drain. While you could use it for hiking and backpacking, I think you’d be much better off choosing a headlamp that lasts much longer between recharges and has the ability to use cold-resistant lithium batteries in freezing or winter weather. We recommend several alternative headlamp models that satisfy this criteria below.

Specs at a Glance

  • Weight: 2.6 oz (including headband)
  • Battery: 1300 mAh, Li-on w/ USB-C charging port on the battery (included), or AAA compatible (not included – Alkaline and Ni-MH only)
  • Max lumens: 520
  • Tilt: 90-degree angle adjustment
  • Modes: Turbo, spotlight, floodlight, red
  • Digital lock: Yes
  • Power Indicator: Yes
  • USB-C charging cable: included
  • Light-diffusing stuff sack: included
  • Charge time: 1 hour 50 minutes

Dual Powered

The Nitecore UT27 comes with a proprietary 1300 mAh Lithium-ion battery with a built-in USB C charging port (charging cable included) but can also be powered with 3 AAA Alkaline or Ni-MH batteries. The rechargeable battery has a built-in USB C port so it can be recharged outside the headlamp body. Additional rechargeable batteries are also available for purchase if you want to carry more than one.

The Nitecore HLB1300 Li-ion Rechargeable Battery included in the UT27 headlamp
The Nitecore HLB1300 Li-ion Rechargeable Battery is included in the UT27 headlamp.

Be aware that the runtime of AAA batteries is about 1/3 less than that of the included rechargeable Lithium-ion battery, so you’re better off powering the headlamp with it if you want to cut down on disposable battery use. For example, the runtime of the low Spotlight (100 lumens) is 10 hours with the rechargeable Lithium-ion battery compared to 6 hours 30 minutes with AAA batteries. The number of lumens and lighting range distance is otherwise identical between the two power sources. More on this below in “Battery Life”.

The Spotlight mode created a focused beam with a maximum throw distance of xxxmeters.
The Spotlight mode provides a focused beam with a maximum throw distance of 128 meters.

Lighting Modes

The UT27 has multiple lighting modes including turbo, spotlight (high & low), floodlight (high and low), red (constant and flashing).

  • The turbo mode shines at a full 520 lumens but shuts off after 30 seconds to prevent power drain. I’ve never found much of a use for it on any headlamp.
  • The spotlight function is designed for runners because it casts a narrow beam a long-distance forward, so you can anticipate the terrain rushing towards you. As a hiker, I think it’s a nice-to-have, although in winter a spotlight can help create deeper shadows that can help you discern a trail in the dark in the snow.
  • The floodlight is the function that most hikers are likely to use in camp for setting up a tent, cooking dinner, or reading at night.
  • The red light is also useful at night because it preserves your night vision and avoids blinding fellow campers who are sitting around the campfire at night. I’ve never found much use for the flashing red light though when hiking or camping.
The floodlight provides a much more diffuse light that’s better for camping
The floodlight provides a much more diffuse light that’s better for camping

Battery Life

The Nitecore UT27 burns an awful lot of power in a short time when it’s set on high in spotlight or floodlight mode, which is what you’d expect a runner to use at night. But its relatively short burn time at both high and low lumen levels indicates to me that the headlamp is intended for someone who needs it for short periods of time and can recharge it very frequently, like immediately after a nightly run. For night hiking or camp use, I’d want a headlamp that lasted a lot longer on a single charge, even if it provided a lower lumen level.

For example, if you compare a hiker favorite like the Nitecore NU32 with the UT27, it has a much different battery life profile that favors fewer lumens and longer runtimes, so you can use it for several hours each night and NOT have to recharge it every day.

For example, the NU32 can run in:

  • high white mode with 190 lumens for 17 hours
  • low white low mode with 33 lumens for 50 hours
  • red constant mode at 9 lumens for 38 hours

That’s more than enough battery life to last through a multi-day backpacking trip without having to recharge the battery.

Power Indicators

While the UT27 has multiple power indicator capabilities, I found it very hard to use or even remember what they all mean. First off, there are not one, but two power indicators. There is a light on the rechargeable battery pack which is either red when the battery requires charging or green when it is full. I get that although it provides limited information.

There is a second power indicator on the headlamp which indicates the power level using flashes: 3 flashes mean a greater than a 50% charge, 2 flashes mean less than 50%, and 1 flash means less than 10%.  (Note: do not look into the light because it is so bright it can blind you.)  However, there are also times when the headlamp flashes quickly, which occurs when the power gets low. I can’t tell the difference between the intentional flashes and the unintentional ones (when the power is dying), so I switch to a different power source or headlamp when the battery goes dead. I think this aspect of the headlamp could be simplified.

Unfortunately, you can only use the UT27 with Alkaline or Ni-MH batteries and not cold-resistant lithium batteries.
Unfortunately, you can only use the UT27 with Alkaline or Ni-MH batteries and not cold-resistant lithium batteries.

Cold Weather Power Leakage

I prefer using the rechargeable Lithium-ion battery out of convenience, but I have noticed that the UT27 battery drains completely over the period of a few days in freezing winter weather. I haven’t been able to benchmark the rate or degree of discharge (I don’t have the instrumentation for that). Unfortunately, the UT27 is NOT compatible with cold-resistant Lithium AAA batteries and is only compatible with Alkaline or Ni-MH batteries, which have very poor cold temperature performance (below freezing) if they work at all.

Nitecore does not publish any temperature limits or advice for the UT27’s rechargeable battery in its product documentation, which is fairly common on other devices that have built-in rechargeable batteries. They also don’t document whether you can recharge the included lithium battery in cold weather (which can harm some batteries) or whether the battery can be used and recharged at the same time, for example, while reading in your tent, which you can do with some of their other models.

The cold-weather limitations and operating parameters of the UT27 rechargeable battery are a concern for me since I frequently hike in winter when the days are very short. I carry a second Nitecore rechargeable headlamp (a Nitecore NU20) on my winter hikes and I have never experienced the same power leakage with it in identical temperatures.

Electronic Lock

The Nitecore UT27 has a digital lock to prevent accidental activation. I consider digital or analog headlamps locks to be a must-have feature. The last thing you want is a dead headlamp because it turned on accidentally in your backpack.

The control logic is difficult to remember unless you use the headlamp all the time.
The control logic is difficult to remember unless you use the headlamp all the time.

Control Logic

The UT27 has two buttons on the top that control its functions. Some of the functions are easy to remember and others, not so much. Unless you use this headlamp all the time, you’re likely to forget how to use it. I prefer very simple headlamps over more complex ones for this very reason.

Comparable Dual-Power Headlamps

These headlamps can be powered by two different battery types, one rechargeable, and one external. They also all have spotlight and floodlight modes. All of them are also compatible with cold-resistant lithium batteries.

Make / ModelSpotFloodRedLockRechargeable
Petzl Actik CoreYYYYY
Fenix HM50R V2YYYY
Petzl Tactikka CoreYYYY
Black Diamond IconYYYYY


The Nitecore UT27 is a 520-lumen dual power rechargeable headlamp that is designed for runners with a spotlight and floodlight capability. While it can put out a powerful beam of light, it has a short burn time that requires frequent recharging. While this may be a good match for a runner who’s out for a short period of intense activity, it’s less suitable for hikers and backpackers who need headlamp batteries either for walking or camp use that last longer between recharges. While the Nitecore UT 27 has the ability to run on Alkaline or Ni-MH AAA batteries, it is not compatible with Lithium batteries which pretty much negates any value that the UT27 might have for cold weather and winter hiking.

There are plenty of dual power headlamps available today that are compatible with lithium batteries, have spotlight and floodlight capabilities, and have much longer runtimes on a single charge. If you’re a hiker or backpacker or need a headlamp for winter use, I recommend you pick one of the ones in the table above and give the Nitecore UT27 a pass.

Disclosure: Nitecore donated a headlamp for this review.

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  1. Many thanks for another excellent review.

    As you indicated, for hiking the NU32 hit the sweetpot in terms of output levels and runtimes (built in1800mAh battery); subsequent Nitcore headlamps are quite inferior in the output/run time stakes.

    Few smaller headlamps are adapted for lithium batteries (why not?).

    For deep winter my preference is for 18650 headlamps which gives the option to use cold weather Li-on batteries therein in (Nitecore & Fenix both manufacture them).

    • Thank you for this information. I have a Fenix HM50R which has a 16340, 700mAh, 3.6V, 5.52Wh battery.

      Prior to taking it out on a winter trip, I thought all lithiums were good in the cold. MAJOR oops.

      Performed worse then my BD Spot w/ 3 AAA lithiums. Also, I never knew it was possible for a headlamp to turn OFF due to low battery..! Maybe I’ve just been really lucky?

      I’ve used Petzl Tikka? BD Spot, two versions of Petzl E-Lite with a lithium coin battery… all of these lights just get really dim on low battery, but have never had one simply turn off (catastrophic as far as I’m concerned… even the dimmest of lights is still useful).

      Anyhow, it’s great to hear of other batteries that do perform in winter. So thank you Sherpa :)

  2. You can lock off the HM50R, and most if not all similar 16340 / 18650 Fenix flashlights, although Fenix does not include this in its instructions. Just unscrew the battery compartment cover 1/2 turn. A few years ago I gave myself a 2nd degree burn when I somehow turned a Fenix light on while it was in my pocket. That motivated me to figure out how to protect myself.

  3. Awesome review. I was considering this instead of nu25 so I don’t have to carry extra micro USB cable, but sounds like I should stick with nu25 ?

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