Nitecore MH12 Pro Overview

The Nitecore MH12 Pro is a duty light for first responders and general-purpose flashlight with a high-capacity 21700 battery, USB-C charging and very slim diameter of 26.8mm for that battery size. It can briefly output nearly 3000 lumens and over 450m of throw, the latter being a particularly strong performance in this size class. It can be configured to start in high by default, or to always start in the last-used mode. The former option may be particularly valuable to first responders who need a powerful light under stress.

When the flashlight was invented, it was so named because the batteries of the day had such poor performance under load that they could only make a brief flash for a few seconds before they had to rest to recover their voltage. The MH12 Pro doesn't have that limitation, but its powerful turbo mode still lasts a mere 22 seconds to prevent overheating. While nearly all modern flashlights have some form of stepdown in their highest mode, that of the MH12 Pro is particularly short.

The performance characteristics of the MH12 Pro are largely the result of Nitecore's first own-brand LED, the UHi 40. Several flashlight manufacturers have recently introduced own-brand LEDs with a round shape like that of the UHi 40, though each has unique characteristics. Unfortunately, one of the characteristics of the UHi 40 is the greenest tint I've ever seen in a flashlight, combined with the worst color rendering index. While the target audience for the MH12 Pro is perhaps not as sensitive to color quality as I am, this is so severe I think everyone with normal color vision will notice that nothing looks right and it's hard to tell red from brown from orange.

The color is so bad I can't recommend the MH12 Pro as a general-purpose flashlight, but for people who need short bursts of long-distance lighting in a slim package, it is conditionally recommended.

Nitecore MH12 Pro Specifications

Spec	-
Battery	1x21700
LED	UHi 40
Color temperature	5765K
Color rendering index	63
Max output	1332 lm
Max throw	308 m
Max sustainable output	1332 lm (temperature-dependent)
Max output at 50% battery	1250 lm (2200 at power-on)
Best efficiency	125 lm/W @ 285 lm
Candela per lumen	22.6 (somewhat throwy)
Length	138.5 mm
Head diameter	26.8 mm
Weight	82 g
Weight with battery	162 g
Charging	USB-C
Low Voltage Protection (LVP)	Yes
Lockout	Mechanical
Approximate price	$90
Product link	Nitecore MH12 Pro
Item provided by	Nitecore
Rating	★★★☆☆ (conditionally recommended)

Highlights

• Throwy for its form factor
• Instant-turbo UI (configurable)
• Excellent thermal regulation maximizes continuous output while preventing overheating
• Very smooth beam shape
• Indicator lights clearly show mode and battery status

Lowlights

• Outrageously green tint (not ANSI white)
• Very bad color rendering
• Turbo output throttles to high in under 30 seconds
• Inefficient relative to competitors

Details and technical analysis

Nitecore MH12 Pro Versions

There's only one version of the MH12 Pro.

Nitecore MH12 Pro Accessories

The accessory bundle includes a 5300 mAh 21700 battery, USB A to C cable, pocket clip, and lanyard.

Nitecore MH12 Pro User Interface

There are two user interface modes for the MH12 Pro, called "daily" and "tactical". To switch between the two, hold the side button down, turn on the light, and wait about five seconds for it to blink.

Daily Mode

State	Action	Result
Off	Half-press tailswitch	Last-used (momentary)
Off	Full-press tailswitch	Last-used
Off	Hold sideswitch, press tailswitch	Ultralow
On	Press tailswitch	Off
On	Press sideswitch	Change brightness (Low -> High)
On	Hold sideswitch	Strobe
On	Hold sideswitch longer	Beacon
On	Hold sideswich even longer	SOS
Blinky modes	Press sideswitch	Last-used constant mode

Tactical mode

State	Action	Result
Off	Half-press tailswitch	Turbo or strobe (momentary)
Off	Full-press tailswitch	Turbo or strobe
Off	Hold sideswitch, press tailswitch	Ultralow
On	Press tailswitch	Off
On	Press sideswitch	Change brightness (High -> Low)
On	Hold sideswitch	Strobe
Blinky modes	Press sideswitch	Last-used constant mode

Only turbo and strobe are memorized in tactical mode.

Nitecore MH12 Pro Modes

Mode	Estimated lumens	Estimated throw (FL1 meters)
Low	38	50
Medium	285	139
High	1276	286
Turbo	1240	433

There's a hard stepdown from turbo to high at 22 seconds. The stepdown is not affected by immersion in water, which does keep all parts of the light cool to the touch suggesting that it's timer-based. While the numbers at power-on are close enough to advertised performance, the product page and user manual claim the performance testing is according to the FL1 standard, which measures at 30 seconds.

Mode	Advertised Lumens	Estimated Lumens	Percent	Advertised throw	Estimated throw (FL1 meters)	Percent
Turbo (initial)	3300	2958	90%	505	457	90%
Turbo (FL1)	3300	1332	40%	505	308	61%

Nitecore MH12 Pro Output, runtime, and efficiency

Mode	Estimated lumens	Time to 80%	Time to 50%	Time to 10%	Efficiency (lm/W)	Current (mA)
Ultralow	1				-	7
Low	38				-	70
Medium	285	8.2 hours	8.2 hours	11.0 hours	125	492
High	1276	4.3 minutes	23 minutes	4.2 hours	120	2860
Turbo	1240	3.9 minutes	26 minutes	3.9 hours	110	None

Fan cooling shows that there is additional throttling based on a temperature sensor, so sustained output and runtime can be affected by wind and ambient temperature in the two highest modes. Cooling the light after it throttles its output results in output smoothly increasing back to the full high level.

Nitecore MH12 Pro Light quality

The color quality of the MH12 Pro is the worst I have ever measured in any flashlight. All modes have such strong green tint that they do not qualify as white light according to ANSI standards. Three modes are more than three times the limit, which is more green than I have seen from any flashlight before. The usual measurements of color temperature and color rendering index are technically not valid for non-white light, but are still useful approximation. The CRI, roughly 63 in most modes is the lowest I have seen in any flashlight.

Measurements are taken from the center spot diffused with DC Fix diffusion film using an X-Rite i1Pro spectrophotometer.

Mode	Color Temperature	Tint Duv	CRI	CRI R9 (deep red)	CRI R12 (deep blue)
Ultralow	5823K	0.0219 (3x extremely green)	62.9	-87.4	30.3
Low	5703K	0.0221 (3x extremely green)	63.0	-85.2	20.5
Medium	5765K	0.0197 (3x extremely green)	62.9	-81.7	32.0
High	5944K	0.0173 (2x extremely green)	63.5	-79.5	33.3
Turbo	7036K	0.0095 (extremely green)	64.3	-63.1	39.7

I could detect no flickering (pulse-width modulation) in any mode by photographing the LED with an electronic shutter. PWM would result in scanlines.

Nitecore MH12 Pro Beamshots

Outdoor

MH12 Pro vs Zebralight SC64c LE (max levels)

MH12 Pro vs Zebralight SC64c LE (sustainable levels)

Indoor

MH12 Pro vs BLF 348

MH12 Pro vs Zebralight SC64c LE

Note that the comparison lights used here are not direct competitors, but reference lights I use in every review.

Nitecore MH12 Pro Batteries and charging

Any protected button-top 21700 battery of good quality capable of over 10A current will work in the MH12 Pro. The included 5300 mAh cell has a little more capacity the usual 5000 mAh seen in this form factor. Flat-top cells don't make contact, probably to protect against inserting a battery backwards without the need for active electronics.

Charging via the USB-C port works from both USB-A and USB-C power supplies, and takes about 4.5 hours. Fully charged, I measured only 4.05V rather than the expected 4.20. Undercharging gives up a little of that 5300 mAh capacity but should extend the battery's service life considerably.

The MH12 Pro will not produce light while the USB cable is plugged in.

Nitecore MH12 Pro Construction and Build Quality

Build quality is very good, with smooth machining and thick anodizing. The square-cut threads turn very smoothly.

The USB port cover is notable for being hard plastic over a rubber seal. It never catches on clothing, and I've never had it come open accidentally for any reason.

Nitecore MH12 Pro Size and ergonomics

I consider the 21700 battery too thick and heavy for casual pocket carry, however the 26.8mm (1.06") head diameter of the MH12 Pro is one of the slimmest on the market. That's not quite enough to put it in my pocket when I'm not expecting to need performance and runtime requiring such a large battery, but could easily be a good fit for an on-call, non-uniformed first responder to carry in a pants pocket.

I found reaching both the tailswitch and sideswitch with one hand to be awkward, making some UI-actions two-handed for those of us who don't wear extra-large gloves. Nitecore claims the MH12 Pro can tailstand; I've only found that to be true on smooth, flat surfaces without vibration or wind.

Acebeam E75, Olight Warrior Mini 2, Nitecore MH12 Pro, Acebeam EC35 II, Skilhunt EC300

The MH12 Pro is notable for being barely larger than the EC35 II despite that light's use of a smaller 18650 battery. The other two 21700-powered lights are noticeably thicker than the MH12 Pro.

Acebeam EC35 II, XinTD C8, Nitecore MH12 Pro, Nextorch TA30C

Over 450m FL1 throw used to require a flashlight shaped like the C8 with a large reflector.

Nitecore MH12 Pro Disassembly and Modification potential

I tried removing the bezel with a pair of strap wrenches. It's glued tight.