This is #4 in Nitecore’s NU-Series lightweight plastic headlamps and it packs a lot of light(s) in a small package. Say hello to the NU25!
This is a very versatile, almost swiss army, type of headlamp, featuring 3 qualities of light with both lockout and special modes in a very lightweight package; oh and not to mention USB charging and a battery indicator. Phew; if that wasn’t enough, I’m actually most excited about the “sweat-blocker” silicon bead on the inside of the headband, which helps keep this very stable on the forehead; I really hope this design feature finds it way onto every Nitecore headband. A couple of things that could be improved is how small and stiff the switches are (much more stiff than the NU10); secondly, the tilting mechanism is super ratchety which means noise and vibrations.
Pretty standard packaging for the NU-series, which come in blister type box which contains:
- Micro USB cable
- Manual (PDF)
At the time of writing this, there is only one LED available, but there are three color options: black light with black band, white light with white band, yellow light with black band. There quite possible may be more colors released in the future.
Current price at time of writing is about $35 USD (see buy links at the very end of the review)
Look & Feel
As typical for NU-series, it is a hard, poly-carbonate type plastic but what is a bit new for this one is a bit of an attractive wood grain texturing to the front; quite classy. The main reflector seems a bit too inset and I wish it was more flush with the body. There is a beaded plastic lens over the secondary lights for a nice even beam pattern. The light is nice and secure in the head mount but can also be taken out.
It’s worth noting that the light cannot regularly tilt 90 degrees down due to the charging port at the bottom, but you can take the whole light out of the head mount and put it back in at a 90 degree angle. The headmount feels pretty sturdy but could use more structure on the sides to make sure it doesn’t bend in half. Tilting the light causes a bit of a ratcheting noise and vibrates on the head a bit too much.
The inside is not accessible or your warranty will be voided.
Only the USB cable is included, as typical for the NU series.
Uses single domed CREE XP-G2 S3 LED. I don’t know what the secondary LEDs are.
*NEW* I purchased a new sensor that can measure beam angle and I have combined it with my light sensor to be able to help show flood vs throw (or I sometimes call spotty).
Nitecore advertises the main LED of the NU25 to have a total beam angle of 100 degree and I’m happy to say that is pretty much what my data shows (feel free to click the pictures for enlargements). The first rectangular graph helps a bit better to see what angle the spill starts at as usually it is quite a bit dimmer then the center. It’s quite possible that a very low lumen outer spill might not register using these methods.
The secondary white and red are much more wider and diffused. The secondary lights have a very wide and smooth transition between the edge and the center.
The NU25 has a much cooler spill tint compared to to the Nichia 219B (in NItecore MT06MD penlight) but has a bit warmer spot in the middle. Nitecore advertiese high CRI but that is probably only for the secondary white.
Overall, I’ve been happy with the output mode spacing but I’m pretty easy to please in this area. Below are some pics from Low to Turbo. I’ve also included my beamshots youtube video which goes through each of the levels.
Here’s some real-world beam shots. All the pictures below are taken with the light in TURBO.
The light has a built-in, non-replaceable, 610mAh rechargeable Li-ion
You can check the status of the batter by pressing and holding the red light switch and the red switch indicator will blink three times for more than 50% battery, twice for less than 50% battery, and once for less than 10% battery.
The light took about 1h 45m to charge which charging current initially at about 0.6A. The below graph shows the current supply to the light through the USB cable. My sensor measured at 1 sample per second for this test. The light can also be turned on while charging! The cover pulls away enough that it isn’t too much in the way. However, the USB port is in the way a bit if you decide to operate the light from a battery bank while wearing the light.
Notes on Methods
I measured the light output in relative LUX and I have not spent time yet to calibrated for lumens or factored % of max output. The charts I’ve provided, while are literally quantitative, I suggest using as a qualitative reference for how the output may behave over time; typically lights aren’t left on this long and the max output can be reset. It’s worth to note that the runtime table provided by Nitecore states, “Runtime for TURBO [and] HIGH is calculated based on theoretical arithmetic.” so there isn’t physically reproducible in my tests.
Temperature measurement condition is at room temp and currently no fan cooling.
I am still very new at doing these types of measurements so I am no authority on on this subject, but please let me know if things don’t look right or you see anything that I could do to improve for next time.
TURBO last only 30 seconds and then steps down to HIGH but is definitely resetable as I attempted to drain the battery as quickly as possible but I was mainly trying to see how hot I could get the light, around 130 degrees F when I stopped. The high mode lasted about 6h 40m and got to temp of 85 dF. The warm white had a very stable output and lasted about 6 hours.
The light is advertised as constant current, non-PWM (pulse width modulation). I didn’t have time to test this but having used the light for the past few weeks, I’m very confident that there is no PWM.
The NU series UI is a bit weird at first because if you wait 3 seconds, no matter what, the next time you click any button, the light will turn off! It’s weird at first but I’d rather have this then having to cycle up the light to turn it off. Also, the modes don’t recycle so off comes up again that way, oh yeah, and if you hold down the red switch within the 3 seconds you can force the light off. It just seems a bit much to turn off the light. Oh yeah and no mode memory for the NU series.
If you own an NU10 or NU30, then the other weird thing is that the power and red buttons are flip-flopped.
If I could be granted one wish for the UI, I wish it was easier to switch from the primary white to the secondary white. You could be out on the trail and need to consult a trail map, but you’d actually have to turn off the light before you can get there. Once you do have the reading light on, the only way to get back to the primary (besides off) is by entering turbo and I’d prefer to start in low, but a double click get you there fast enough I suppose.
The NU20 would be a better comparison for size and the NU30 would be more comparable for features but all I’ve got is the NU10.
- Sweat blocker silicon bead in headband makes for very stable wear and great for active use
- Love the warm secondary white
- USB rechargeable in under 2 hrs and can operate while charging
- Stays very cool, less than 90 degrees F
- Very lightweight
- Constant current output
- USB charging
- Buttons are a bit stiff
- Ratcheting noise and vibrations when tilting the light
- Would like more structure on the head mount bracket
- 30 sec turbo feels too short, would have liked 3 min maybe
- Can’t wear comfortably while powered by battery bank
- UI really wants you to turn off the light
- Would have liked UI to switch between primary and secondary white a bit easier
The current price for the light is about $35 USD and if you appreciated my review and would like to support me, feel free to check out this product on amazon using my affiliate link (does not cost you more, amazon gives me very small % of their profit):
Amazon Link: NITECORE NU25 360 Lumen Triple Output Headlamp
Thanks for Reading!
- CivilGear Reviews received this product for testing and providing an honest review.
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