Eagletac D25 AAA (XP-G2 S2, 1xAAA/10440) Review: BEAMSHOTS, RUNTIMES+


May 27, 2006


The D25 AAA is the latest 1xAAA keychain light from Eagletac. Although it uses the standard twisty interface, it does have a few surprises up its sleeve. ;) Let's see how it compares to the competition in this class.

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

  • LED: CREE XP-G2 Cool White S2 LED, or Nichia 219B SW45 D220 LED (CRI 92), or Edison Opto 395nm UV LED (Note: I had the XP-G2 S2 for this review)
  • ANSI FL-1 Output/Runtime: Hi 85 lumens / 0.7 hr – Mid 40 lumens / 1.3 hrs – Lo 8 lumens / 6 hr
  • XP-G2 S2 Beam Distance: 45m
  • XP-G2 S2 Beam Intensity: 500cd
  • Nichia 219B Beam Distance: 32m
  • Nichia 219B Beam Intensity: 250cd
  • 1xAAA or 1x10440
  • Operating voltage: 0.8V - 4.2V
  • Supports 1.2V NiMH, 1.5V alkaline, 1.5V(1.7V) lithium, 3.7V li-ion
  • Compatible battery (diameter/length) AAA: (10-10.5mm/44-45mm)
  • Battery with protruded bottom top required
  • High switching frequency (1MHz) controller for more compact circuitry design
  • Circuit: Low internal resistance design offers up to 90% efficiency
  • Non-dimming constant current regulation for all output levels
  • Zero standby current
  • Supports output dimming with li-ion battery
  • Allows LED direct drive with li-ion battery at high mode
  • Reflector: Optical grade acrylic TIR optics
  • Material: HAIII hard anodization aerospace aluminum
  • Strong rare earth magnet installed at the tailcap (grey color coated)
  • Battery reverse polarity protection
  • Ultra low internal resistance phosphor bronze springs (silver coated)
  • Warranty: Ten years performance guaranteed warranty, Read flashlight regular maintenance
  • Dimensions: Head Dia. 0.55 inches (14 mm), Body Dia. 0.5 inches (13 mm), Length:
    2.7 inches (70 mm)
  • Weight 0.4 ounces (13 grams)
  • Waterproof: IPX-8
  • Package Contents: D25AAA flashlight, Spare o-rings, User Manual, Stainless steel clip, Strong rare earth magnet (grey color coated)
  • MSRP: ~$29

Packaging is pretty basic, consistent with this class. Outside of the box has the usual detailed specs. Inside, you get the light and standard extras – extra o-rings, pocket clip (attached), manual, and product inserts.

You'll note the wide range of emitters available. This review of the XP-G2 S2, specifically.




From left to right: Panasonic Eneloop Pro NiMH AAA; Eagletac D25 AAA; Thrunite Ti; Fenix LD02; Olight i3S (2014); L3 Illumination L08.

All dimensions directly measured, and given with no batteries installed (and without keychain ring, where removable):

Eagletac D25 AAA (with clip): Weight: 13.4g, Length: 69.8mm, Width (bezel): 14.1mm
Fenix LD02 (with clip): Weight: 16.5g, Length: 76.9mm, Width (bezel): 14.4mm
Fenix E99Ti: Weight: 18.7g, Length: 66.1mm, Width (bezel): 14.1mm
Foursevens Preon P0: Weight 13.0g (with keychain clip), Length 55.0mm, Width 12.6mm (bezel)
Foursevens Preon P1: Weight 15.3g (with keychain clip), Length 75.6mm, Width 14.0mm (bezel)
Klarus Mi X6: Weight 16.2g, Length 72.9mm (battery installed), Width 12.8mm
L3 Illumination L08: Weight: 22.4g, Length: 77.8mm, Width (bezel): 17.0mm
Lumintop Worm Aluminum: Weight: 14.3g, Length 72.0mm (battery installed, off), Width 14.1mm (bezel)
Olight i3 (2013/14): Weight 12.3g, Length: 69.3mm, Width (bezel): 14.0mm
Thrunite Ti3: Weight: 11.5g, Length: 69.9mm, Width (bezel): 13.6mm
Titanium Innovations Illuminati Aluminum: Weight 13.9g (with keychain clip), Length 68.8mm, Width 14.0mm (bezel)








Anodizing is typical matte black, with no chips or blemishes on my sample. White lettering is clear and sharp. There is very little knurling – just a bit on the head. The body would be rather slippery to handle, if it weren't for the attached clip (which seems solid). The light is easy to use one-handed.

With the pocket clip in place, the light will not roll. Clip base holds on to the light extremely securely, and cannot be pulled off. You can however easily unscrew the tailcap portion of the light, and simply remove the clip (and re-assemble without). Of course, the clip not reversible.

Screw threads actually seem somewhat trapezoidal (i.e., square cut). Threads are anodized to different colors – you can pick what you like (red shown here). Light uses a twisty control interface.

There is a physical reverse polarity feature in the head, so only standard button-top AAA cells can be used. This will likely be a problem is you plan to use 10440 – most ones I've seen have too large of a button top. I needed to solder a dab to the center of the head to be able to use my 10440s.

There is a spring in the tailcap, which should limit potential denting of batteries (always a concern on twisty lights)

There is a small cut-out on the tail for a split ring attachment point. Tailstanding is good. There is a fairly strong magnet in the tailcap, allowing you to stand the light horizontally on any metal surface.



Unlike many keychain lights (which use a small reflector), the D25 AAA uses a small optic for focusing. I'm starting to see this more and more though (e.g., my recent Fenix LD02 review).

Note there is no damage to the optic above – those are just reflections being picked up and distorted. Please see my detailed beamshots later in this review.

User Interface

Turn the light on by fully tightening the head against the body (loosen to turn off). Change modes by doing a rapid loosen/tighten of the head from on. This is the standard twisty interface.

Mode sequence is mainly: Lo > Med > Hi, in repeating sequence. However, after two continuous passes through this sequence, seven auxillary modes are activated (in sequence). Full sequence is thus:

Lo > Med > Hi > Lo > Med > Hi > Strobe 1 > Strobe 2 > Strobe 3 > SOS 1 > SOS 2 > Beacon 1 > Beacon 2.

There is no mode memory, and the light always defaults to Lo if it is off for more than a second or two.


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

For all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information or clarifications before publicly releasing the video.

As an aside, if you want to get an instant notification for every new review that I post, you can subscribe to my YouTube channel. The vids go public at the same time as the reviews here on CPF. :whistle:


There is no sign of pulse width modulation (PWM) at any output level on the D25 AAA. There is however a circuit pattern visible on the lower outputs on my oscilloscope (which is uncommon on many lights).


Again, there is no obvious circuit signal on Hi.



There is a high frequency re-occurring patter on Lo/Med. However, this is not PWM, and it is not visible to the eye. As usual, I simply report on anything that I can measure with my oscilloscope. This does not manifest as any visual effect that you can see.

Strobe 1:

The main strobe is a high frequency strobe, measured at 10 Hz on my D25 AAA.

Strobe 2:

The second strobe mode is an alternating or "oscillating" strobe, switching between 6.3Hz and 15.0Hz every 2 seconds.

Strobe 3:

The third strobe mode is really a slow flash signaling strobe, with a 1.7 Hz frequency.

SOS 1:

First SOS is relatively fast.

SOS 1:

Second SOS is relative slow.

Beacon 1:

First beacon mode is a 1.5 sec full power flash every 13 secs.

Beacon 2:

Second beacon mode is a reduced power flash of 0.5 secs, every 2.5 secs.


For white-wall beamshots below, all lights are on Max output on an Eneloop NiMH AAA. 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.







The optic on the D25 AAA focuses a lot more light into the hotspot (i.e., spill beam is relatively dim). As a result, these pics make it look like the D25 AAA is brighter than it actually is (scroll down for actual output measures).

Testing Method:

All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. 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.

My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, 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).


Max output is reasonable for the class, although not as high as some other recent lights I've tested. The low mode seems higher than most other multi-level lights, although likely still reasonable for most.

To explore output levels further on AAA vs 10440 Li-ion, here is an estimated lumen table on all modes:


It is really only the Hi mode that is significantly different on the D25 AAA.


For all my AA/AAA reviews, I've started including Panasonic Eneloop Pro NiMH cells. For AAA, these are basically the same as the second generation Sanyo Eneloop "XX-powered" Pro cells, now manufactured under the Panasonic name. They have a typical capacity of 950mAh (900mAh min), which is higher than the original Sanyo AAA Eneloops (typical 800mAh). For the time being, I will show both types of cells in my reviews.

Standard AAAs:









Ok, that's a lot of data up there. First thing I noticed is the relatively poor efficiency of the Med/Lo mode on the D25 AAA. :thinking: I am at a loss as to why this would be the case – although I note the Eagletac specs are at least consistent with my testing results.

On Hi mode, performance is pretty good – although there is a drop-off in max output on L92 for some reason.

It seems to be really on the Lo/Med modes where this light significantly under-performs the competition. :shrug:

10440 Li-ion:



I don't have a lot of data on recent lights on 10440, but the results above suggest a similar pattern (i.e., reasonable efficiency on Hi, poor efficiency on Med). Note that max output drops rapidly on Hi on 10440, soon approaching a slightly higher output than standard AAA NiMH Hi levels.

Potential Issues

Efficiency of the Med/Lo modes is much lower than you would have expected for this class (although is consistent with published Eagletac specs). Hi mode seems perfectly reasonable, in comparison.

Lo mode (min output) is not as low as some in this class (i.e., no moonlight mode).

There is no memory mode, and the D25 AAA always starts on Lo.

The reverse polarity protection feature prevented any of my 10440s from working (i.e, you need to have a very small projecting button on the positive battery terminal). A dab of solder on the center of the contact disc in the head was required to get 10440s working on my sample.

The D25 AAA drops down from Hi rapidly on 10440, as you might expect. After a few mins runtime, output is only slightly higher than the standard AAA NiMH Hi mode

Preliminary Observations

In physical terms, the D25 AAA is a nice addition to the 1xAAA keychain line from Eagletac. I like the build and user interface, and found the light comfortable and easy to use. But the unusually low efficiency of the Lo/Med modes makes this light an under-performer compared to the competition.

I am unclear as to why lower mode efficiency is so impaired on this light, :thinking: but I note that Eagletac's specs are consistent with my testing (i.e., they accurately report low runtimes on Lo/Med). Hi mode performance is consistent with this AAA keychain class, with decent output and runtime on all batteries. And official support for 10440 Li-ion here is a definite bonus. :thumbsup:

Physically, I like the solid clip (although it is of course not reversible). The tail area magnet is a cute feature as well, allowing the light to stand on any metal surface. And the choice of thread anodizing color gives you the option for a bit of extra bling. ;)

The only physical feature I didn't like was the reverse polarity protection – this prevented all of my stock 10440s from functioning (due to their positive buttons being too wide and/or too short to make proper contact). Even my rare earth magnets were too big to work, as they made contact with the raised reverse-polarity detection ring. In the end, I had to add a large dab of solder to the center of the contact disc in the head, to circumvent the protection and allow 10440 contact. :shrug:

Beam pattern is more focused than most lights in this class, due to the use of an optic. I find the Eagletac optic produces more throw (at the expense of spill) than the Fenix optic in similarly sized lights (i.e., the LD02 or E99Ti). Beam profile is clean.

If Eagletac could get the Lo/Med mode efficiency up to the standards for this class, I would expect the D25 AAA to be a very competitive light. It still has a lot going for it, but in its current form, expect do to more frequent battery charging/changing than typical. :whistle:


D25 AAA supplied by Eagletac for review.
Last edited:


Newly Enlightened
Jun 21, 2013
Hmmm...I thought EagleTac was ditching this clip for one that is removable? Guess that's not going to happen anytime soon.

I'm waiting for the updated clip and I'd like to get the UV version. :)


Newly Enlightened
Apr 1, 2013
Thanks for the review. Seems a lot is compromised in AAA lights to keep them small, of course that's the purpose.


May 27, 2006
Hmmm...I thought EagleTac was ditching this clip for one that is removable? Guess that's not going to happen anytime soon.
Ah sorry, I should have shown how easy it is to remove:


The tailcap easily unscrews, and the clip comes right off. Advantage of this approach of course is that the clip cannot come off by accident. :)


Newly Enlightened
Jun 21, 2013
Ah sorry, I should have shown how easy it is to remove:

The tailcap easily unscrews, and the clip comes right off. Advantage of this approach of course is that the clip cannot come off by accident. :)

Ahhhh...much better. Thanks!


Feb 26, 2014
Selfbuilt, you rock! Thanks always for your incomparable reviews.

Did you use a pair of pliers to unscrew the tailcap so you could remove the clip? (I guess I have weak hands?)



Flashlight Enthusiast
Dec 30, 2011
The original version of these lights were sold with permanently attached clips and rear caps despite being advertised as removable.
So now I have 2 like that and I am sure this is why that question has come up?

Now that I am sort of soured to the ET lights from this they seem to have released a revision where they actually are as advertised in the beginning,go figure?

Great Review Selfbuilt as usual!

I have been carrying mine in my watch/coin pocket since they came out and despite the clip issue I am really loving the light.


Newly Enlightened
Jun 13, 2015
Can anyone confirm which sorts of 10440's will work in this flashlight?
Specifically, are there any button-top, protected 10440's that fit right out of the box?

Thanks! I'm looking at adding this light to the collection but would like to be able to use it with protected 10440's.


Newly Enlightened
Oct 5, 2016
Question re Recent Change from XP-G2 S2 to S3 LED

SelfBuilt - wonderful review! The technical information you supply is extremely useful to separate fact from fiction.

I'm interested in this particular light due to its size, magnetic base, ability to use 10440 batteries, and its usage in emergency situations with its beacon & SOS modes. Eagletac has very recently changed the emitter of this light to Cree's XP-G2 S3 LED.

I have a couple of questions for anyone who's an expert in such things. Do you anticipate that the relatively poor efficiency that SelfBuilt observed in Lo/Med modes will improve with the emitter upgrade? And do you anticipate that the new S3 emitter will be noticeably brighter? Thanks in advance for the assistance!