Nitecore EA4 (XM-L U2, 4xAA) Review: RUNTIMES, BEAMSHOTS, VIDEO and more!


May 27, 2006
Warning: pic heavy, as usual. :whistle:

Is this some new mystery light that I need to keep under wraps?


No, it is just the Nitecore EA4 – an incredibly small 4xAA light that actually fits inside a toilet paper roll. :laughing:




Let's see how it fares relative to the competition ... :whistle:

Manufacturer Reported Specifications:
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).

  • Utilizes a CREE XM-L U2 LED
  • Output: Turbo: 860 Lumens, High: 550 Lumens, Mid: 300 Lumens, Low: 135 lumens, Lower: 65 lumens
  • Runtime: Turbo: 1hr 45min, High: 2hr, Mid: 4hr 30min, Low: 11hr, Lower: 22hr (based on 4.x 1.2V 2400mAh AA)
  • Boasts a peak beam intensity of 20,000cd and a throw distance of up to 283 meters
  • Novel 'Unique Integrated Technology' offers a more sturdy and lightweight body.
  • Integrated “Precision Digital Optics Technology” provides extreme reflector performance
  • Innovative single button two-stage switch offers a user-friendly interface (patented)
  • Eight rapidly switchable brightness modes to select from
  • High efficiency circuit board provides up to 22 hours runtime
  • Integrated power indicator light displays remaining battery power (patented)
  • Power indicator’s secondary function displays battery voltage (accurate to 0.1V)
  • Reverse polarity protection prevents damage due to incorrectly inserted batteries
  • Stainless steel retaining ring protects the core components from damage
  • Toughened ultra-clear mineral glass with anti-reflective coating
  • Constructed from aero grade aluminum alloy
  • Sturdy HAIII military grade hard-anodized
  • Waterproof in accordance with IPX-8 (two meters submersible)
  • Impact resistant to 1.5 meters
  • Tail stand capability
  • Dimensions: Length: 117mm, Head diameter: 40 mm, Tube diameter: 41.8mm
  • Weight: 159g (without battery)
  • Accessories: Quality holster, lanyard, spare O-ring
  • MSRP: ~$70

The EA4 comes in similar packaging to the other Nitecore Explorer series lights. Inside the cardboard box, you will find the light, good quality holster, simple wrist lanyard, extra o-ring, manual, and warranty card. Note that unlike most of the Explorer lights, there is actually a cut-out for attaching the wrist strap on the EA4 tailcap. :rolleyes:




From left to right: Duracell AA NiMH; Nitecore EA4; Olight S35, S65; Jetbeam PA40; Sunwayman M40A.

All dimensions are given with no batteries installed:

Nitecore EA4: Weight: 161.6g , Length: 117.9mm, Width (bezel): 40.2mm
Lumintop PK30 6xAA: Weight: 454.0g, Length: 218mm, Width (bezel): 62.0mm
Fenix TK45 8xAA: Weight: 307.3g, Length: 202mm, Width (bezel) 50.6mm, Width (tailcap) 44.0
ITP A6 6xAA: Weight: 209.9g, Length: 174mm, Width (bezel) 48.0mm, Width (tailcap) 37.8mm
JetBeam PA40 4xAA: Weight: 184.0g, Length: 183mm, Width: 40.8mm (bezel), 42.1mm (max width)
Olight S65 6xAA: Weight 215.4g, Length: 180mm, Width (bezel): 38.7mm
Sunwayman M40A 4xAA: Weight: 247.0g , Length: 145mm, Width 57.0mm (bezel)

The EA4 is incredibly small for a 4xAA light. :eek:oo: As you will see below, it is also quite "throwy", thanks to its relatively deep reflector. In case you are wondering how they fit all this together, there is a cut-out image of the light on the side of the box:


And now the rest of the light:






In some ways, I suppose the EA4 looks like a miniature TM11/TM15. It is very cylindrical, but with ridges along the body to help with grip. There is no knurling, except on the tailcap (where it helps when performing battery changes). The power button is actually fairly "grippy" (more on this in a moment). Overall grip is ok, but the light does have a tendency to roll away from you. Anodizing is a flat black, and seems in excellent shape on my sample.

Body labels are rather extensive, as with the TM-series lights. But they are very legible and clear.

Battery handle is quite compact, but easily houses 4xAA (alkaline, NiMH or L91). The battery compartments are molded right into the aluminum, with the cells in a series arrangement (as opposed to the TM11/TM15, where they are in parallel).

Screw threads are anodized, but it doesn't matter – there is no physical lock-out, because the connection is carried by the contacts in the tailcap and not the body (i.e., it is fully dependent on the tension on the springs). In my handling, you will need to loosen the tailcap more than half-way off to even begin to break this contact (i.e., it's not very effective as a lock-out).

The light can both tailstand and headstand. There is a cut-out on the base to allow you thread a wrist-lanyard through.


Switch design

The switch design is particularly distinctive. In is a two-stage electronic switch, and in many ways functions similarly to the TM11 or TM15. But it also has a lot of differences – first off, the switch is smaller, with a rubberized "grippy" texture. This actually makes it relatively easy to access with bare hands (i.e., you will feel the difference easily).

Secondly, the switch feel is different from either the TM11 or TM15 – you don't need to press it as hard to activate the first or second levels. It's hard to describe in words, but I would describe the pressure needed as more subtle than those TM-series lights.

There is also a faint blue LED located underneath the switch cover. This is used to signal the state of the light (i.e., battery status, voltage, etc). Scroll down for an explanation of the interface.



The light has a flat stainless steel bezel ring, with a rather deep, smooth reflector. This should provide very good throw for this size light. The cool white XM-L emitter was well centered on my sample.

UPDATE May 14, 2013: I have done some additional beamshot comparisons with two different diffuser covers that fit the 40mm opening of the EA4 - the Nitecore NFD40 and Olight M22-X diffuser. The NFD40 diffuses the beam to a greater extent than the M22-X diffuser. Scroll down the review for actual beamshot comparisons.







I find the Olight M22-X filter to be a better fit, as it is very snug on the light and has a lower profile than the NFD40. The diffuser lens can also pop out of NFD40 more easily, given the design of the rubber holder.

UPDATE May 28, 2013:
Based on a good tip from SCEMan, the Butler Creek Blizzard flip-open scope cover (size 5 - 1.6-1.69 inch, 40.64-42.92mm) fits perfectly. All you have to do is add your own diffuser film to the clear plastic lens, and you have a proper flip-style diffuser cover. I used some adhesive D-C-Fix diffuser material that I tested for jzmtl a few years back, for the pics below.




And next to the Olight M22-X diffuser:


Note the hinge is spring-loaded, so it flips up with ease. It also seems to stay closed petty well, as long as you fully seat it (by pressing down on the two protruding flanges to close). Nice construction with the metal retaining ring holding the plastic window in place. You just need to get the metal retaining ring unhooked from the first plastic restrainer, and then can easily proceed in sequence (start from the end that is jagged, as you can slip a fine jeweler's screwdriver or tweezer in there). Once you get it out, the clear plastic lens falls out - which you can cover with your choice of material, and then reassemble. You could even sandpaper the clear lens, etc.

User Interface

The EA4 uses a very similar interface to the TM15's innovative two-stage electronic switch.

Like the TM15, for Turbo output, press the switch all the way and release (for constant on), or press firmly and hold for momentary on. Also like the TM15, this "Search/Turbo" set also has a slightly lower Hi mode, which you can switch to and from (when locked on in Turbo) by half-pressing the switch and releasing. There is no mode memory on this mode set – the light always comes on in Turbo. Turn off by a full press and release.

For the lower "Daily" modes, only partially press the switch from Off (again, hold for momentary, release quickly for locked-on, like the TM15). Light will come on in the memorized lower output mode. As described above, to switch modes when on, simply half-press and quickly release the switch again. The light will advance to the next output, in repeating sequence of Lower > Lo > Med > Hi. The light has memory on this mode set, and will retain the last lower output used. Turn off by a full press and release.

Along with the "grippy" rubberized button cover, the pressure required to activate the various modes has changed slightly from the TM15 (i.e. it is less now, with less of a traverse).

Like the TM15, the light will read-out the voltage of the cells when you first connect the head, by a series of blue flashes under the switch cover. After the initial voltage read-out, the light will then flash once every three seconds (when off), to let you know you are in standby mode. The indicator stays constantly illuminated when the light is on. It will start to flash as the batteries begin to drain, at increasing frequency.

A "hidden" strobe mode can be accessed by two rapid full presses of the switch from On. Turn off or double-click again to return to constant output modes. There is also a SOS and Locator Beacon mode that can be accessed by pressing and holding the switch all the way down when in Strobe mode. Simply release the switch to select SOS/Beacon as the light rotates through the options.

There is a switch lock-out mode that prevents accidental activation (and lowers the standby current, see below). From On, press the switch all the way down and hold for more than one second. There will be a brief flash - when you subsequently release the switch, the light will turn off and enter the lockout mode (and briefly flash out the voltage of the cells).

Note that to exit the lockout mode, you have to do like the TM15 and fully press and hold the switch firmly for more than one second. The EA4 manual erroneously states to that you need to press the switch 3 times quickly, which is not the case.

Video Overview:

For information on the light, including the build and user interface, please see my new video overview:

Video was recorded in 720p, but YouTube typically defaults to 360p. Once the video is running, you can click on the configuration settings icon and select the higher 480p to 720p options. You can also run full-screen.


There is no sign of PWM that I can see, at any output level – the EA4 is fully current-controlled, as claimed. :)


The "hidden" strobe is a true variable strobe, with a variable overall frequency and pulse duration. The average strobe rate is ~14 Hz, which combined with its variable nature, makes it quite disorienting. :green:


Beacon is a brief full power flash, once every 2.2 secs.

Standby Drain

A standby current drain is inevitable on the EA4, due to the electronic switch in the head. Unfortunately, I'm not able to easily measure it, as the batteries are arranged in series (i.e., I would have to connect everything under tension, without the tailcap in place, to get a reading).

For the other single-cell members of the Nitecore Explorer series, I found this current to be in the in the low uA range, with occasional spikes up to the low mA range when the indicator would flash. For the parallel multi-cell Li-ion TM-series lights, I typically found these to be in the high uA range, with low mA spikes for the indicator flash. The end result was that most of those related lights would give you several months of runtime before the batteries would be exhausted, under normal Standby usage.

Note the EA4 includes an electronic lock-out mode. To lock-out the switch and reduce the standby current. I don't know how much this lowers the current, but it is likely to be significant. I recommend you make use of it. :)

Note that although you can also break this current by unscrewing the tailcap, but it needs to be nearly completely unscrewed off to be reliable. It is the tension on the springs that maintains the connection (i.e., it has nothing to do with the anodized threads).


And now the white-wall beamshots. ;) All lights are on Sanyo Eneloop NiMH, at the maximum supported number for the given models (4x, 6x or 8x). Lights are about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.









Overall beam pattern is similar to the Olight S65 or Jetbeam PA40, although the E4A is slightly throwier, with a slightly more defined hotspot. There were no artifacts or irregularities in the beam of my sample.

UPDATE May 14, 2013: Here is a comparison of the EA4 beam with the two different diffuser covers shown earlier in this review. The light is on Hi (not Turbo), about 3/4 of a meter back from a white wall.










As you can see, the Nitecore NFD40 diffuses the light to a greater extent than the Olight M22-X diffuser (i.e., the hotspot is further reduced with the NFD40 filter). I also find this filter "warms" up the beam tint slightly (compared to the M22-X filter, which didn't seem to have much effect on tint).

I have measure output by ceiling bounce, and the Olight M22-X filter reduces overall output by ~16%, compared to ~18% for the Nitecore NFD40. So while it looks in the beamshots like the NFD40 cuts the light output to a much greater extent, this is mainly a subjective effect of the greater diffusion. I would suggest you choose between the filers based on your preference for degree of diffusion and fit.

Testing Method:

All my output numbers are relative for my home-made light box setup, a la Quickbeam's method. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lightbox values to Lumens thread for more info.

Throw/Output Summary Chart:

My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see ANSI/NEMA FL-1 Standard page for an explanation and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).


My centre-beam throw measure for the EA4 was 21,500 cd (lux @1m equivalent), which is very consistent with the Nitecore specs. Certainly very throwy for this size light.

The EA4 is quite bright for the class, as you can see above. Note that I make no claim as to the absolute value accuracy of my lumen estimates – they are just a useful guide for relative comparisons between lights of a given class that I have tested.

Here are my lumen estimates for all levels of the EA4:


One interesting thing I noticed – at the higher levels, my EA4 was consistently brighter on alkaline than it was on NiMH Eneloop. Not sure why - it's not something I've noticed on other lights of this class. :thinking:

Typically, I find pretty good concordance of my lumen estimates with Nitecore – in this case, my values seem to be slighty lower at most levels. Note that if anything, my lumen estimate values are typically higher than the specs of most other lights.

Output/Runtime Comparison:

Note: as always, the the NiMH runtimes are based on standard 2000mAh Sanyo Eneloops.





Note that the EA4 has a pronounced drop-off on Turbo after 3 mins runtime – to a level pretty close to the Hi mode.

Overall output/runtime efficiency is what you'd expect for a good current-controlled light at these levels. :) Moreover, initial output on Turbo is much higher than other lights I've tested in this class. For example, the output and runtime of the EA4 Hi is similar to the Jetbeam PA40 on Turbo, and the EA4 on Med is similar to the PA40 on Hi. Of course, Lo is where the very good efficiency of this setup really come into play, with extended runtimes.

Note that like many lights in this class, alkalines are really not well suited for the high drain rates on Turbo/Hi.

Potential Issues

Due to the electronic switch in the head, the light has a stand-by current when waiting to receive a button press. I have not measured it in this case, but on most Nitecore lights it tends to be in a range that will drain fully-charged batteries over a course of months.

The electronic switch is fairly small, and it may take you a few seconds to find it when you want to activate the light. That said, I actually found it easier to locate by touch than I expected (thanks to the grippy switch feel). It may also take you some time to get used to the relative pressure required for the two-stage switch, although I personally got used to it very quickly.

The LED indicator under the switch is very dim, and it can be hard to see under typical illumination conditions (good in the dark, though).

You cannot easily lock out the light physically, so I recommend you use the electronic "soft lock-out" in regular use – both to lower the standby current, and to help prevent accidental activations. Note that it only takes a sustained press of >1 sec to unlock the light, so accidental activation is still possible (although far less likely).

The light doesn't have as low a minimum output level as most other lights in this class.

Preliminary Observations

I'm impressed by the output and beam pattern of the EA4, for its diminutive size. Frankly, I am amazed that Nitecore could make a relatively throwy light with 4xAA, and still be smaller than a number of floody 3xAAA lights I've seen. :eek:oo:

Hand feel for the light is good, although I would personally prefer a few more grip elements and a bigger switch. It is not very heavy, even with batteries installed. The user interface is good for me, as it is virtually the same as the TM15 that I reviewed recently. The switch does have a different feel than the TM- or P-series lights from Nitecore, but it took me no time at all to get used to it and consistently get exactly the mode I wanted. It was also surprisingly easy to isolate by touch alone, given the very grippy, rubberized switch cover (although this could still be improved further).

No surprises with overall output/runtime efficiency or regulation – they remain very good, consistent with a good current-controlled circuit. :) Note however than the EA4 uses a timed step-down (at 3 mins), as opposed to the more sophisticated thermal sensor-driven step-down on the TM-series lights.

Output levels are well spaced, and easily accessible. The light is impressively bright on max, although it does step down to a more typical high after 3 mins. You can always cycle back to Turbo after the light steps-down, but its hard to know how well the heatsinking would perform if you were to try it repeatedly. Also, I wouldn't mind an even lower low, but I always carry a dedicated light that purpose.

The beam pattern is very clean – and relatively throwy for a light this size (which was the design intent). You have a couple of options for diffuser/filter covers for this light - Nitecore makes available a flat diffuser cover and filter set (NFD40 and R/G/B filters) and a diffuser cone (NDF40). I have also tested the Olight M22-X diffuser/filter covers, which are a perfect fit. See the beamshots and discussion earlier in this review to see how these two main options compare.

All told, the EA4 is very endearing light – its compactness and high output impress anyone I show it to. It has also has a fairly advanced interface (i.e., equivalent to TM15), with a low of nice features. If you are looking for an easily pocketable, high-output thrower that runs on standard batteries, the EA4 is definitely worth a look. :wave:


EA4 was supplied by Nitecore for review.
Last edited:


Flashlight Enthusiast
Dec 8, 2007
Any runtime of High mode on alkaline?
I think that it should provide 45 minutes of flat regulation, and then another 45 minutes of declining output, before the long goodnight.


Dec 1, 2012
hi, if you look at the Throw/Output Summary Chart it states 4x eneloop (2000mah,1.5v) was used :)


Newly Enlightened
Nov 8, 2012
Salzburg, Austria
I have tried to measure the standby and lockout drain on my EA4W and the results are:
standby: 0.55 mA when the blue LED is off and 7 mA when it is on that means on average about 3.8 mA or 22 days time with a 2000 mAh Battery
lock-out: 0.133 mA or 1.7 years of battery life.
It seems worth to lock-out because the standby drain is due to the blue light pretty high.


May 27, 2006
I have tried to measure the standby and lockout drain on my EA4W and the results are:
standby: 0.55 mA when the blue LED is off and 7 mA when it is on that means on average about 3.8 mA or 22 days time with a 2000 mAh Battery
lock-out: 0.133 mA or 1.7 years of battery life.
It seems worth to lock-out because the standby drain is due to the blue light pretty high.
Thanks for the measurements. The "average" current drain under regular usage probably isn't quite that bad, given that the higher current flash is only a fraction of a second once every three seconds. But based on your current draws, I would still expect that 2000mAh batteries would be depleted in well under two months.

Good to know the lock-out mode is such a low current, in contrast.


Jul 16, 2012
I have tried to measure the standby and lockout drain on my EA4W and the results are: standby: 0.55 mA when the blue LED is off and 7 mA when it is on that means on average about 3.8 mA or 22 days time with a 2000 mAh Batterylock-out: 0.133 mA or 1.7 years of battery life.It seems worth to lock-out because the standby drain is due to the blue light pretty high.
Ouch!! I've made a habit of locking out most of the time becasue of this.


May 27, 2006
Just updated the review with the Hi mode alkaline graph (and fixed the figure legend for the Turbo run):


Basically, not much of a difference between Turbo and Hi. You get an extra ~5 mins or so of regulated output on Hi, but lack the extra 3 mins of initial Turbo. :shrug:

That's with Duracell alaklines, but performance should be similar on other brands.

I'm afraid that's it for runtimes for this review, at least for now. I don't plan to do L91 at this time, as this isn't part of my regular testbed (i.e., I haven't tested any of other multi-AA lights with them either). Depending on donations, I may try to start doing these in the future, we'll see.


Jul 16, 2012
i like this flashlight,but this flashlight is not good for anti roll design.:D
I would normally complain to no end about lights without an anti roll (Fenix E11), but since the EA4 is so stable on its tail I'm fine with how it is.


May 27, 2006
I would normally complain to no end about lights without an anti roll (Fenix E11), but since the EA4 is so stable on its tail I'm fine with how it is.
Yes, this is my reasoning as well. I comment about the lack of anti-roll in the video, and generally like a clip on thinner lights to prevent roll. But the much wider base on the EA4 (compared to a 2xAA light) makes the light a lot more stable for tail-standing, which helps (i.e., you don't have to lay it down on its side, unless trying to look at something horizontally).


Newly Enlightened
Sep 19, 2010
Great review!
The EA4 definitely has a lot going for it, but a 65 lumen micro mode seems somewhat of a paradox. :)
Last edited:

Latest posts