Nitecore P23i

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Nitecore doesn’t make “tactical” lights, they make tactical lights. Now, three years after Nitecore added i-Series battery support to their popular P20-series lights, they’ve released the new P23i, sporting a new emitter that provides over 50% increase in lumens and over 130 meters farther throw, and entirely new mode selection options.
All this is on top of Nitecore’s instant turbo and strobe access, which should make this light just as strong a product as its predecessor, the Nitecore P20i, which we also reviewed. Let’s see if it lives up to its name.

Packaging:

Because Nitecore lights are sometimes sold in physical stores, they’ve made their packaging very attractive. No basic boxes here; the P23i has a glossy self-portrait on the front and plenty of detailed information all over the box. For the physical store aspect, there’s a tab at the top which it can be hung from.

Inside is a molded plastic tray holding the P23i on top and accessories underneath. It’s easy to remove due to an additional pull tab on one end, and you won’t spill everything, because there’s a bottom to the tray! Nitecore has some of the nicest packagings I’ve seen in a light.

Inside the box, you’ll find

• Nitecore P23i with NL2150HPi 21700 battery inside
• Detachable clip
• Lanyard
• Spare o-ring
• Holster
• USB-C charging cable
• Instruction manual
• Warranty card

Being a tactical flashlight, the P23i is designed for ease of operation. It can be stored in the holster either bezel up or bezel down, so you can carry it the way that best suits your usage. Speaking of the holster, it’s made from tough webbing and closes with a generous amount of hook and loop, so the light won’t be falling out. You can attach it either through a plastic D-ring, or a fixed or hook and loop closing belt loops, though it’s about an inch and a half across, so it won’t fit in standard MOLLE webbing.

Most of the P23i feels smooth, as there’s not much knurling, but with all the channels and different shapes on the body, you’ll still be able to hold it well. One change from the previous model (an upgrade, in my opinion), is a pair of arms extending from the tail cap to shroud the dual buttons. This allows the light to tail stand, although it’s somewhat unstable because of how small they are, and protects from accidental activation, since there is no electronic lockout on the P23i.

Like many Nitecore lights, the P23i has two buttons; a forward-clicky mechanical switch for momentary and full on/off, and a second generation electronic Strobe Ready™ mode paddle. These are very different in design, so they can’t be mistaken for each other. While the light is on, you can click the mode paddle to cycle through the modes, or hold for momentary turbo. While it’s off, the mode paddle gives you instant access to Nitecore’s variable 16Hz-20Hz strobe for a high powered dazzling effect.

A new feature on the P23i is the inclusion of two sets of modes: Daily Mode and Tactical Mode. In Daily Mode, you have ultralow, low, mid, and high available to you, which you can cycle through using the mode paddle. Tactical Mode runs in the opposite order: Turbo, mid, low, and ultralow, though in this mode, turning the light on will always start in turbo, instead of memorizing the last level you used.

On its own, the P23i has a tendency to roll, but if you add the clip, that can help hold it in place. The clip slots onto one of two channels on the light’s body, and can be attached in either direction. Neither is deep carry, but it does a good job. Really, the biggest problem with the clip is that it makes it more difficult to put the P23i back in the holster. You may want to choose one or the other instead of using both at once.

There’s also a lanyard, if you’re interested in those. It can be attached to the tail cap arms, though with only one hole, it can interfere with tail standing, or to one of the holes in the clip. I always find having a lanyard attached to the middle of the light, for example, on the clip, gets in the way of usage, but it’s an option.

The P23i feels balanced and isn’t too front heavy when using it in the overhand hold, which is probably how one would be using it most, but it fits well in my hand for the standard hold, too. Both switches are easy to access with my thumb and easy to activate, and if stored bezel-down in the holster, makes it easy to draw and use fairly quickly without the need to make adjustments. Being that it’s a real tactical light, even though it has a Daily Mode set, I’d say this is better used for tactical-type situations, where you’d make more use of things like the Strobe Ready™ paddle, momentary, and instant access to turbo, but if you’ve got that need, having the Daily Mode set makes this light able to do double duty.

The P23i only comes in Nitecore’s standard, HA-III, black anodized, aircraft-grade aluminum, and that should be all you need in a tactical light. I haven’t encountered any scratches on mine during my test period, so it’s pretty tough.

Only the tail cap can be removed to expose the anodized threads, so mechanical lockout is possible if you wanted an extra layer of safety. The tail cap screws and unscrews smoothly, though it feels like the contacts may be catching partway on the battery and causing it to rotate, too. Either that or I’m feeling the contacts grind against the battery terminal.

As I mentioned before, there’s very little knurling on the P23i, but where it lacks in that, it makes up for in other ridges and shapes, which help with grip.

They also advertise that it’s compatible with a number of weapon mounts and other separate accessories, but those are not covered here.
Nitecore’s warranty covers the light for 60 months (that’s 5 years!) against manufacturing defects, and the NL-series battery for 12 months. As you can see, Nitecore is confident in their products.

On the business end of the P23i is a Luminus SFT70 with a smooth reflector. THe SFT70 is a quad-die emitter, meaning it’s essentially four emitters in one, in a 5mm x 5mm package. Pretty compact, but also powerful, due to using 6 or 12V instead of a standard single emitter’s 3V. The smooth emitter helps focus the beam downrange for plenty of throw, while leaving a generous amount of spill for viewing the surrounding area.

The SFT70 only comes in low CRI, high CCT (this light uses 6500K), but the P23i isn’t about enthusiast-quality light. Those are entirely different categories of light. The P23i is about quantity, and getting it downrange, which the SFT70 does quite well. You can see that in the measurements below. The beam is very white without any green and even has negative DUV on turbo. 

Those components are covered by a glass lens with purple anti-reflective coating on both sides, and topped off by a crenulated strike bezel. The three larger crenulations are topped with silicone nitride ceramic balls for striking, but they’re so small, you’ll have to hit the object (presumably a glass window) dead-on, or you’ll just be hitting the aluminum edges of the bezel. While the crenulations aren’t high, they do actually extend far enough to block some light from the beam, making cutouts in the otherwise perfect circle of spill, which is very large. 

For any enthusiasts that are still around and want details, here’s what my Opple Light Master Pro showed. 

Mode	CCT	CRI Ra	DUV	Flicker
Ultralow	5951	66.7	0.0063	37118 Hz
Low	6116	67.5	0.0049	40537 Hz
Mid	6179	67.8	0.0039	19943 Hz
High	6423	68.9	0.0019	19943 Hz
Turbo	7020	70.9	-0.0015	19862 Hz

Dimensions: 

Nitecore P23i	Millimeters	Inches
Length	143 mm	5.6 in
Head diameter	32 mm	1.25 in
Body diameter	24 mm	0.9 in

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

Weight: 

Nitecore P23i	Weight in grams	Weight in oz
Without battery:	115 g	4.1 oz
With battery	191 g	6.7 oz

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

Flashlight size comparison with its competition:

As you can see, the P23i is competitively sized for a 21700 light, so it packs quite a punch!

Group 1: Acebeam E70, Nitecore SRT6i, Nitecore P23i, Mateminco FW3S, ThruNite TN12 Pro

Group 2: Emisar D4V2, Nitecore SRT6i, Convoy S2+

Since the SFT70 is either a 6V or 12V emitter, the P23i uses a boost driver to provide the necessary voltage.

As I mentioned before, the P23i has two buttons: A circular on/off switch, and a flat Strobe Ready™ mode paddle. I’ll refer to them here as the circular and mode buttons.

Available modes: 

• Ultralow, low, mid, high, turbo

Available blinky modes:

• Strobe Ready™ variable strobe

From OFF:

• Daily Mode
  • Half-press circular: Momentary selected mode 
  • Single click circular: Engage selected mode 
  • Hold mode: Momentary strobe
• Tactical Mode
  • Half-press circular: Momentary turbo 
  • Full press circular: Engage turbo 
  • Hold mode: Momentary strobe

From ON:

• Daily Mode
  • Single click circular: Off 
  • Click mode: Change level (ultralow-low-mid-turbo)
  • Three fast clicks mode: Engage strobe
  • Hold mode: Momentary turbo
• Tactical Mode
  • Single click circular: Engage turbo 
  • Click mode: Change level (turbo-mid-low-ultralow)
  • Three fast clicks mode: Engage strobe
  • Hold mode: Momentary turbo

Mode memory:

• In Daily mode, the P23i will remember the last used level
• In Tactical mode, the P23i will always start in Turbo 

Shortcuts:

• To Turbo: Hold mode pedal from on
• To Strobe: Hold mode pedal from off; triple-click from on

Low voltage warning:

• The battery indicator light on the side of the head will blink rapidly when the voltage gets low and the light will step down until it turns off at 2.9V.

Strobe/blinkies

• Nitecore’s Srobe Ready™ lights use a variable strobe mode. When holding the mode button all the way down, it starts at 16 Hz and speeds up to 20 Hz over the course of about 5 seconds, then repeats. This is done to further disorient whoever’s on the receiving end.

Lock-out mode: 

• Unscrew the tail cap at least a quarter turn. There is no electronic lockout. 

PWM

• PWM is not visible

Additional/summary info on the UI: 

• Having two mode sets makes the P23i very versatile! Speaking of changing the modes…
• In order to change the mode set between Daily and Tactical,
  • Hold the mode paddle (yes, this activates strobe)
  • Unscrew the tail cap; the light will toggle modes and quickly blink out the new mode:
    • 1 blink = Daily mode
    • 2 blinks = Tactical mode
  • Release the mode paddle and tighten the tail cap again.

The P23i uses Nitecore’s i-Series battery, specifically, the NL2150HPi. This is a 5000mAh 21700 battery, but it’s customized to have a positive pole and negative ring on both sides so that some of their tail cap features and accessories can use battery power without the need for an inner sleeve to carry the signal between the head and tail. It makes for some very useful features like the Strobe Ready™ e-switch, and their tail cap accessories such as the TSL10i, a replacement tail cap with RGBW indicator LEDs in it, and the RSW2i, another tail cap with a USB-C connected remote pressure switch.

While that customization is helpful, that does make the battery proprietary. You must use the NL2150HPi with the P23i; it will not work with a standard 21700. Thankfully, the P23i has onboard USB-C charging, so you don’t necessarily need to buy a new charger to recharge it. If you are a heavy user of your lights and you go through multiple batteries in one session, you would need to buy more batteries and likely a charger, as it takes over four hours to charge via the on-board charging. That’s a long charge.

While charging, the blue battery indicator light will blink slowly until it’s finished, at which point it will stay on. One neat feature is that when you unplug the USB-C cable from the light or insert the battery, the battery indicator light will blink out the charge (ex. 4 blinks, pause, 1 blink = 4.1V). My test model blinks out 4.3V when fully charged, but when I tested the battery with my multimeter, it showed 4.2V, so the light’s voltage readout was slightly off, but not bad. This blue indicator light will also remain on while the light is on, too.

To obtain these numbers, I used a very rudimentary integrated shoebox and ceilingbounce on my Samsung Galaxy S10. Measurements have been calibrated using a standardized calibration light provided by 1Lumen.

Lumen measurements (for each mode)

Pretty good output here! Solid regulation, too. While the P23i doesn’t quite hit high and turbo, it’s still very close, especially on turn on.

Mode	Specs	Lumens @turn on	Lumens @30 sec	Lumens @10 minutes
Ultralow	50	58	58	58
Low	250	351	351	353
Mid	800	825	816	798
High	1500	1431	1408	781
Turbo	3000	2795	2345	907
Turbo at 3.6V	–	2691	2271	1521

Due to the nature of the battery and switches, it’s not possible to accurately measure amperage.

Battery Life: Runtime graphs

Look at those regulated graphs! Low is a straight line, right across the board. Ultralow would be like that, too, but I didn’t test that 45 hour runtime. Mid and high hang out around 600-700 for most of their runtime, and you can see Nitecore’s patented Advanced Temperature Regulation raising and lowering the output a little throughout the life of the battery.

Mode	Specified runtime	Measured runtime ANSI	Time till shut off
Ultralow	45h	–	–
Low	10h	10h 28min	10h 28min
Mid	4h	3h 12min	3h 53min
High	2h 30min	2h 49min	3h 30min
Turbo	30min*	2h 50min	3h 27min

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

The numbers for candela were obtained with a UNI-T UT383S luxmeter at 5 and 15 meters, then averaged.

Mode	Specs	Candela measured	Meters	Yards
Ultralow	1130 cd	846 cd	58 m	63 yd
Low	4700 cd	5076 cd	142 m	155 yd
Mid	14,900 cd	17,132 cd	262 m	287 yd
High	27,960 cd	31,514 cd	355 m	288 yd
Turbo	55,300 cd	50,760 cd	451 m	493 yd
Turbo @ on	–	57,740 cd	481 m	526 yd

I measured the P23i over specifications for almost every mode; turbo at 30 seconds didn’t quite hit its mark, but it does when it’s first turned on. 480 meters, or even 450 meters is a long way to throw!

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.

These were taken with a Samsung Galaxy S22+ using pro mode and the following settings: 

• WB 5000K
• ISO 200
• Speed 0.5

Distance to the other end of the playing field is 100 meters, and the distance to the bridge is 400 meters. 

Beamshots of the following flashlights compared:

• Nitecore SRT6i
• Mateminco FW3S
• ThruNite TN12 Pro

Disclaimer: This flashlight 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.