Warning: pic heavy, as usual.
This is a review of a pair of dedicated 1xAA (WK25B) and 1x14500 (WK26) lights from Xtar. As the external styling and construction is similar, I will compare them together. Unless specified otherwise, I will always start with the WK25B in the comparisons.
Manufacturer's Specifications: WK25B
- LED: CREE XP-E R3
- ANSI Illumination levels： High: 150Lm, 50min - Low: 15Lm, 15hr - Strobe
- Max Range： 85m (1800cd @1m)
- Impact Resistance： 1m
- Water Resistance： IP-X 6
- Materials： Anodized aircraft 6061 aluminum alloy
- Working Voltage： 0.8~1.5V
- Battery： AA 1.5V Battery
- Switch： Tail cap
- Size：22.5mm（Head dia）x 17.5mm（Body dia）x 102.5mm（length）
- Net Weight ：38g（Excluded battery））
- Package Contents： Flashlight, Lanyard, O-ring
- MSRP: ~$20
Manufacturer's Specifications: WK26
- CREE XP-E R3
- ANSI Illumination levels: Low : 5Lm, 200h – Mid: 135Lm, 2hr30min – High: 250Lm, 1hr - Strobe - SOS
- Max Range： 105m (2760cd @1m)
- Impact Resistance： 1m
- Water Resistance： IP-X 7 , underwater 0.5m
- Materials： Anodized aircraft 6061 aluminum alloy
- Working Voltage： 2.7~4.2V
- Battery： 1 x 14500 Battery
- Switch： Tail cap
- Size： 22.5mm（Head dia）x 17.5mm（Body dia）x 102.5mm（length）
- Net Weight ：38g（Excluded battery）
- Additional Functions： DIY Mode, Memory function
- Package Contents: Flashlight, Lanyard, O-ring
- MSRP: ~$20
Packaging is identical for the two models – both lights came in a hard cardboard box with built-in packaging foam. Inside you will find the light, basic finger/wrist lanyard, manual and warranty card. Oddly, there were no extra o-rings included on my samples, although the WK26 came with a Trustfire protected 14500 Li-ion battery.
From left to right: Duracell alkaline; Xtar WK25B, WK26; Sunwayman V10A; Thrunite Neutron 1A; Zebralight SC51; Fenix LD10-R4; 4Sevens QAA.
All dimensions are given with no battery installed:
Xtar WK25B: Weight 42.9g, Length: 102.3mm, Width (bezel): 22.5mm
Xtar WK26: Weight 42.4g, Length: 102.2mm, Width (bezel): 22.5mm
Lumintop Silver Fox: Weight: 98.1g, Length: 94.2mm, Width (bezel): 21.7mm, Width (grip-ring): 25.8mm
Sunwayman V10A: Weight: 58.1g, Length 100.6mm, Width (bezel): 23.1mm
Tiablo: Weight: 45.7g, Length: 101.2mm, Width (bezel): 19.9mm
Thrunite Neutron 1A: Weight: 60.4g, Length: 105.6mm, Width (bezel): 22.0mm
Xeno E03:: Weight: 48.1g, Length 96.7mm, Width (bezel): 21.5mm
Overall dimensions are in keeping with the 1xAA class, although they may be a bit longer than typical.
Overall build is fairly basic on both models. The walls feel fairly thin (i.e., not thick like the 1xRCR WK21 reviewed recently).
Anodizing is a shiny black on my WK25B, more of a matte finish on the WK26. There were no nicks or damage on either sample. There is no real knurling on the lights, but there are some fine fluted ridges on head, body and tailcap that perform the same function. Grip is ok, but I would prefer it a little more aggressive. Labels are bright white against the black background.
There are no clips included with the lights.
Lights have flat bezel openings (i.e., not scalloped like the WK21).
The lights can tailstand, but my WK25B was very wobbly (especially when off).
Both lights use a forward clicky switch, with a fairly short traverse (especially so on my WK25B sample). Although switch height inside the tailcap is somewhat adjustable, I found it difficult to access the button on my WK26 no matter how tightly I screwed it in. The light remained hard to access with a thumb press (i.e., button too recessed into the tailcap). This seems to be the flip-side to wobbly tailstanding (i.e., the WK25B sample was much easier to press).
Tailcap threads are not anodized, so no tailcap lock out is possible.
Basic use is similar between the lights: lightly press the forward clicky tailcap switch for momentary on, click for locked on. Soft-press or click to advance modes.
The difference is in mode sequence, options and memory.
For the WK25B, sequence is Hi > Lo > Strobe, in repeating sequence. There is no mode memory – the light always comes on in Hi.
The WK26 is a fully customizable light, just like the WK21 I reviewed previously. You can set from one to up to five possible modes. The standard five output modes are Lo > Med > Hi > Strobe > SO, in repeating sequence (note that should be SOS, but the light actually does SO morse code repeatedly instead ). But there are 16 possible mode combinations available to choose from.
Just like the WK21, you set the WK26 mode combination through the four pairs of contacts on the inside of the head (note that 2^4 = 16 combinations). By default, all four contacts pairs are disconnected. This gives you the five output modes listed above. You can connect individual paired contacts to give you access to other mode combinations. Normally, you would do this by soldering the contact points between the pairs (but sometimes the old graphite trick with a pencil works to give you temporary connectivity).
There is a table in the manual that explains what each of the mode options are. For example, if you connect the fourth contact only, you get Lo > Hi > Strobe > SOS. If you connect the last three pairs of contacts, you get Hi > Strobe only, and so on and so forth. Please refer to the manual for all the specific pairings.
There is mode memory on the WK26, and the light remembers the last setting you left it (if you leave it off for at least several seconds).
For a more detailed examination of the builds and user interfaces, please see my video overview:
Video was recorded in 720p, but YouTube defaults to 360p. Once the video is running, you can click on the 360p icon in the lower right-hand corner, and select the higher 480p to 720p options, or even run full-screen.
Both lights use PWM to control their Lo/Med modes, but at different frequencies:
My WK25B used 900 Hz PWM for its Lo mode, and my WK26 used 500 Hz for its Lo and Med modes. While certainly acceptable, higher frequencies are always preferable for those are sensitive to PWM flicker.
Strobe modes were comparable, at 9.7Hz and 9.9Hz, respectively.
The heads of the lights look identical – both use a Cool White XP-E emitter (R3 output bin reported). Both were well centered on my samples. Reflectors are both smooth finish and reasonably deep. As a result, I expect better than average throw with a well-defined hotspot.
Which brings me to the white-wall beamshots. All lights are on Hi on 1xAA Sanyo Eneloop or 1x14500 AW protected Li-ion, 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.
WK25B (1xEneloop-based lights):
WK26 (1x14500-based lights):
As expected, both lights have well-defined hotspots for their respective battery classes. However, both lights also had more beam rings than typical (it is worse in real life than you can tell in these pics, with lots of very fine rings). Honestly, it's been awhile since I've seen this many beam rings on 1xAA lights (i.e., reminds me of the old XR-E days ).
All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com 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 recently devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox 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 http://www.sliderule.ca/FL1.htm for a description of the terms used in these tables.
Throw is indeed top-of-class for the WK25B among the 1xAA lights. Overall max/min output specs are otherwise extremely similar to the XP-G-based version of Xeno E03.
Throw is again top-of-class for the WK26 among 1x14500 lights. However, max output is typically lower than the XP-G and XM-L lights compared here.
Note that the reported ANSI FL-1 throw/beam distance values for these lights seem to be understated by a considerable amount.
Oh, and don't bother with primary 3V 14505 batteries in the WK26. They aren't able to supply enough voltage to keep the output running stably. For example, I measured ~70 estimated lumens at activation, but less than ~40 estimated lumens at 3 mins in this light.
For the WK25B, runtime pattern is very similar to the XP-G-version of the Xeno E03 (although with a bit less runtime on primary cells). This seems to be a decent showing for a XP-E R3.
Reported ANSI FL-1 output and runtime numbers seem reasonably accurate for the WK25B.
Max output runtimes on 14500 seem very good for the XP-E R3 emitter, generally matching or exceeding most XP-G E4/R5 lights. Runtimes on Med mode are certainly acceptable, but not quite as impressive. Regulation is very flat at all levels tested, in keeping with the restricted voltage range of the light.
For the Max output 14500 run, I've included the bundled Trustfire protected 14500 cell as a dotted-line. As you can see, runtime is similar to my AW1 4500 protected, except the Trustfire cell drops out of a regulation a bit earlier, for slightly extended overall runtime.
Like with the WK21, reported ANSI FL-1 output numbers seem a little inflated for the WK25B, but runtime values seem accurate.
UPDATE FEBRUARY 21, 2012: I have done a Lo mode runtime on the WK26 with the supplied Trustfire 14500, and got somewhere between 74-78 hours to when it dropped down to below 10% initial output (i.e. ANSI FL-1 standard). While short of the 200 hr specification, this is better than I expected. Note however that Lo mode runtimes are highly variable between samples, and are greatly affected by small differences in Vf and other characteristics of the emitter.
Build is budget-class on both models, with simple screw threads (no anodizing), no bezel ring, limited extras, etc. Grip could also be better.
Tailstanding and ease of access to the switch are somewhat mutually-exclusive. Switch height is partially adjustable, but I still found it very hard to access on the WK26.
Both lights have excellent throw for their respective battery classes, but with very ringy beams.
Lights use visible PWM for the low/med modes, but at generally acceptable frequencies (900Hz for the WK25B, 500Hz for the WK26).
Mode sequence is very basic on the WK25B (i.e., no mode memory, strobe on main sequence, etc.). The WK26 is a more sophisticated product with customizable modes (but this requires soldering contacts in the head).
Each model has a narrow voltage range (i.e. 1x14500 will damage the circuit of WK25B, and 1xstandard AA will not light up in the WK26).
The WK25B and WK26 share a similar overall budget build and budget price. Each light has its own restricted voltage range (and concomitant limited battery support). Where they differ is in the circuit design – the 1xAA WK25B again has a budget feature set, whereas the 1x14500 WK26 has a more advanced and customizable control set.
Overall build is certainly acceptable for the budget price. But I would personally like to see a few upgrades to improve usability (i.e., better threads with anodizing for lock-out, easier to access tailcap switches, etc.). The swtich on my WK26 was particularly difficult to access (i.e. forget using your thumb). Note that the lights do not seem as solid the WK21 that I reviewed recently.
Thanks to the XP-E emitter choice – with relatively deep and smooth reflectors - beam pattern is quite throwy for the class (and throwier than Xtar's own numbers suggest). But this comes at the expense of beam profile, which is very ringy on both lights.
Circuit performance is quite acceptable on both models, although the limited voltage range restricts your battery choice. The 1xAA WK25B performs remarkably similar to the Xeno E03 XP-G on Lo and Hi on standard batteries (but the E03 is a more sophisticated product with 14500 support, significantly improved build, and better user interface). The 1x14500 WK26 is very similar to the 1xRCR WK21 that I reviewed recently (in fact, I wouldn't be surprised if it were the same circuit). Output/runtime efficiency is certainly reasonable on the WK26, given the full regulation pattern.
Of the two AA-sized lights reviewed here, I personally prefer the customizable interface and memory mode of the 1x14500 WK26. The flexibility of altering the number of output modes is appreciated (especially by those of us who don't like blinking modes in the main sequence ).
WK25B and WK26 were provided by Xtar for review.