Ultratac K18

3 years ago written by

I received the UltraTac K18 from GearBest for the review.

Light source: CREE XP-G2 S2 LED, impervious to shock with a 50,000 hours lifetime, Max. output is 360 lumens;
Convenient one-handed operation;
Direct Thermal Path (DTP) Copper MCPCB;
Constructed of machined aerospace-grade aluminum with Type III hard-anodized finish, non-slip and comfort design with detachable wrist lanyard;
Support four variable lighting modes (high, medium and low) plus strobe via the side button switch;
All the joint with O-ring sealed, Shock and water resistant;
Reverse polarity protection;
Compact size and light weight;
AR coated lens, 99% light transmittance;
Compatible with 10440 Li-ion battery;
Two-way clip provides more carrying options.

Dimentions (L x d): 2.95″ x 0.55″ (75mm x 14mm)
Weight: 2.82oz. (80g) – with package
Construction: Machined Aerospace-grade Aluminum
Battery Type: 1 x 10440 Li-ion Battery / 1 x AAA Alkaline Battery / 1 x AAA Ni-MH Battery
Runtime: 1 hour for high
Bulb Type: Ultra Bright CREE XP-G2 S2 LED
Bulb life: 50,000 hours, an unbreakable
LED Brightness: 360 lumens
Lighting Modes: High / Medium / Low / Strobe
Operation: Side Button switch
Available Color: Black, Red, Blue (Type III hard anodized)
Market Applications: EDC, Tool, Emergency

Set includes:
1 X UltraTac K18 AAA Keychain LED Flashlight
1 X AAA Alkaline Battery
2 X Spare O-ring
1 X Keychain
1 X User documentation
1 X Warranty Card

There are different colorations available: black, red, gold, blue and stainless steel. I got the black one.

The outer box has the specs

Remove it and you have the black box

The UltraTac logo is shiny
The inside of the box

What’s inside: light with the clip and the splitring installed, alkaline AAA battery, manual, spare o-rings and lanyard.

Some pics of the light

XP-G2 emitter in a very small OP reflector

There is an eyelet at the end of the tailcap, big room for lanyard and splitring. However, no tailstand since the eylet is not squared but round shaped.

The electronic switch at the head (it protrudes around 1 mm). The clip and the switch (nice feedback, requires some pressure to work) also doubles as an anti rolling device.

The positive pole is flat, you will need button top cells to run the K18.

Anodized threads allow the physical lockout of the light.
If you buy the stainless steel version of the K18, physical lockout will not be possible since the threads are not anodized.

Size comparison: 14500 Battery, Thrunite TiS, UltraTac K18, JetBeam Jet-u, 10440 battery.

From off: a long click will turn the light on at the last used mode.
When the light is on: a short click will cycle the modes in low – mid – high loop, a double click will go into strobe mode.
A long click will turn the K18 off.
From off a double click will activate the electronic lockout of the light. To unlock it you have to do a double click.

If you fear the accidental activation of the switch, you can physically or electronically lockout the light; personally I find easier to untwist the head (physically lockout), it is quicker than going through the unlocking procedure and completely removes the parasitic drain.

Output and runtime
The testing has been done with GP Recyko+ AAA nimh and Efest IMR 10440 350 mAh battery.

I see that the max output on the nimh is lower (I have almost 90 lumens, other reviewers measured 100-110 lumens). I believe I get less result because they use newer Eneloop or Eneloop pro AAA batteries, and I use the old batteries I got. If you use more performing batteries, expect better results in term of output and runtime.
I measured 1620 Cd with a 10440 battery, 300 with my nimh batteries.

Sampling rate is 6” for high levels, 90” for the mid levels.

Beware that the k18 will drain the 10440 way above the minimum recommended voltage (during the medium teste it even brought the voltage below 1 volt, less than 2 volt for the high test).

My thoughts
Fit and finish are fine, but, the box goes the extra mile.
I am impressed with the quality of the packaging and the way the K18 is presented.
The K18 costs more than other AAA lights, but it has an electronic switch, officially supports 10440 batteries and has a great regulation on the levels I tested, both with nimh and li-ion.
Too bad about the over discharging of the 10440 batteries.
After I remembered to keep the switch pressed to turn the light on (I have many lights around and I often change the one I carry, so I have trouble remembering all the interfaces), I liked the interface. The long press needed to turn the light on, avoids most of the accidental activations. However, I usually let the head a bit unscrewed.
I always had only twisty AAA lights. This is the only one I own with an electronic switch at the head. I like it because it allows easier operation with one hand.

If you plan to use your K18 with 10440 batteries, my advice would be to charge them often and consider replacing the battery when you see the output fade.

Thanks to: AntoLed for the camera and the luxmeter.

Article Categories:
10440 · AAA · EDC · Flood · Keychain · Reviews