Ultratac K18 (XP-G2 S2, 1xAAA Ni-MH, Alkaline, Li-ion) Review

candle lamp

Flashlight Enthusiast
Joined
Jun 16, 2010
Messages
1,572
Location
South Korea
S-0.jpg


The K18 is a 1xAAA light from Ultratac features a side switch, and compatible with 10440 Li-ion, Ni-MH and Alkaline battery. The packaging is the nice cardboard box. You can see the features and specifications on the front, side, and back of the packaging.
.
.
S-1.jpg


S-2.jpg


The light come with removable pocket clip (attached), spare o-rings, key chain, user manual, and warranty card.
.
.
Manufacturer Specifications from user manual :

• Max. output of 360 lumen
• Convenient one-handed operation
• Direct thermal path (DPT) copper MCPCB
• 3 light levels plus strobe
• Reverse polarity protection
• Compact size and light weight
• AR coating lens, 99% light transmittance
• Compatible with 10440 Li-ion battery
• Two-way clip provide more carrying options
• Battery option : 1xAAA Alkaline, Ni-MH, 10440 Li-ion battery

S-3.jpg

.
.
S-4.jpg


S-5.jpg


S-6.jpg


S-7.jpg


S-8.jpg


The K18 looks small for the class. The anodizing is a light blue and no flaws on my sample. Labels are sharp and clear in bright white against the colored background. There are small patterned rectangles over the head and body tube.
The light has a built-in split-ring attachment point on the tail of the light, which prevents tailstanding. It also makes the light slightly taller. The light has no tail switch. Fit and finish look good.
.
.
S-9.jpg


The light has 2 parts. The pocket clip works as a good anti-roll device as well.
.
.
S-10.jpg


There is a patterned rectangles band on the head. The head has a clean looking cylindrical design with a electronic side switch. The side switch looks rubber, and it has a good feel to touch and has short travel, which produces a little clicking sound. The K18 switch is protruding and this may cause the risk of accidental activation. The light has reverse polarity protection to protect from incorrect battery installation (i.e., the K18 has a physical reverse polarity protection. You can see a very thin layer on the positive contact in the head).
.
.
S-11.jpg


S-12.jpg


The light comes with a lightly textured reflector (OP) and uses a XP-G2 S2 emitter. Centering of the emitters was pretty good on my sample.
.
.
S-13.jpg


The pocket clip looks sturdy and hold onto the light very securely. It is reversible, allowing both head-up or head-down.
.
.
S-14.jpg


The battery tube is mostly covered in raised patterned rectangles. With the pocket clip attached, overall grip is acceptable, but not as grippy as actual knurling. The wall thickness of the body is 1.3mm. The light feels reasonably solid.
.
.
S-15.jpg


The light uses a spring in the tailcap, like many lights in this class.
.
.
S-16.jpg


The screw threads are triangular-cut of good quality. Threads are well machined, and anodized which allows the light to be locked-out. As supplied, threads are lubricated. Screw threads action is smooth with no cross-threading or squeaking in my sample.
.
.
S-17.jpg


The K18 come with an included key chain. This large key chain can be quickly put or removed from the key-ring. While the key chain attachment point is quite useful, the attachment point prevents tailstanding.
.
.
.
User Interface

There are two modes (i.e., general mode & strobe mode).

1) General mode
On-Off and output switching is controlled by the electronic side switch. Pressing and holding (0.5sec) the side switch will turn the light on, and another pressing and holding turns it off.

When on, a quick press and release (i.e., click) of the side switch will proceed Low -> Med. -> High, in repeating sequence. The light has mode memory, and remembers the last output level used when you turn the light off and back on.

2) Strobe mode
The "hidden" Strobe is accessed by double-clicking the switch when on. A single quick press and release (i.e., click) of the switch will return to the previous output level in general mode. The strobe has no memory.
.
.
Standby Current Drain

Due to the electronic side switch interface, the K18 is drawing a small current when the light is fully connected. But I was not able to measure it, as I had blown the mA (including μA) current fuse in my DMM. So I was told by Ultratac that their test result is between 40~50μA when using 1.5V voltage power supply. For 1xNi-MH AAA (750mAh), that would translate into around 1.7~2 years before it would be fully drained. This is negligible, not much of a concern. But I would recommend you lock-out the light when not in use or to prevent accidential activation.
.
.
S-18.jpg


S-19.jpg


From left to right, Panasonic Eneloop AAA (750mAh), Fenix E99 Ti (XP-E2), Rayus C01 (XP-G2 R5), Ultratac K18 (XP-G2 S2), Skillhunt Ramble-I (XP-E R2).
.
.
.
Measured Dimensions
S-20.jpg

.
.
S-21.jpg


The K18 is not a very small light, but good size to hold and use. You can use it as an EDC light. Overall build quality seems high.
.
.
PWM
S-22.jpg

I can see PWM flicker on Low and Med. output when waving the light fast. But the flicker on both levels is not noticeable, you will not be annoyed in real life.
The K18 shows no sign of PWM on High. I hear a very small buzzing sound on Med. only when the light is very close to my ear.
.
.
Runtime
S-23.jpg


The runtime to fall to 10% of its initial output from 30 seconds after the point the light is first turned on (i.e., based on ANSI FL-1) for High is as follows :

I don't have other runtime data in this class for comparison, but the results above says that efficiency on Ni-MH seems better than other battery sources. Unfortunately I was not able to test on 10440, as I don't have 10440 Li-ion cell.

The K18 drops down rapidly on Alkaline.
.
.
Beamshot

1. White door beamshot (about 50cm from the white door) on max. output on 1xPanasonic Eneloop AAA (750mAh)
- ISO125, F/8.0, 1/25sec, Auto white balance
S-24.jpg
S-25.jpg

S-26.jpg
S-27.jpg

.
.
- ISO125, F/8.0, 1/100sec, Auto white balance
S-28.jpg
S-29.jpg

S-30.jpg
S-31.jpg

.
.
- ISO125, F/8.0, 1/800sec, Auto white balance
S-32.jpg
S-33.jpg

S-34.jpg
S-35.jpg

.
.
- ISO125, F/8.0, 1/2000sec, Auto white balance'
S-36.jpg
S-37.jpg

S-38.jpg
S-39.jpg


The beam profile is pretty comparable to the others. It shows a bit wider hot spot than other lights. The overall beam profile is good. The beam has a cool tint, but warmer than I expected.
.
.
2. 3.5m Indoor Beamshot on max. output on 1xPanasonic Eneloop AAA (750mAh)
- ISO125, F/2.8, 1/10sec, Auto white balance
S-40.jpg

.
.
S-41.gif


The above pictures make it look like all lights are not brighter than they actually are. So I took more pictures with 1/5sec condition which are much more close to real situation as below.
.
.
- ISO125, F/2.8, 1/5sec, Auto white balance
S-42.jpg

.
.
S-43.gif

.
.
3. 7.0m Indoor Beamshot on max. output on 1xPanasonic Eneloop AAA (750mAh)
- ISO125, F/2.8, 1/10sec, Auto white balance
S-44.jpg

.
.
S-45.gif


The above pictures make it look like all lights are not brighter than they actually are. So I took more pictures with 1/5sec condition which are much more close to real situation as below.
.
.
- ISO125, F/2.8, 1/5sec, Auto white balance
S-46.jpg

.
.
S-47.gif

.
.
Overall Impressions

• Build quality seems high
• The light can't tailstand
• Anti-roll indentations on the body
• Possibility of accidental activation from off, due to the slightly protruded electronic side switch
• Standby current drain (40~50uA) is inevitable, but not much of a concern
• Physical lockout function
• Physical reverse polarity protection function
• 10440 Li-ion is supported
• Mode memory for all output levels except Strobe
• True Moonlight mode is not available
• Use PWM for Lo, Med., but may not distract the user
• Overall beam tint is cool white, but warmer than expected

Ultratac K18 provided by Ultratac for review.
 
Last edited:

yizhiren

Newly Enlightened
Joined
Jun 17, 2010
Messages
10
Nice review. If you could test it with 10440 Li-ion battery that would be perfect.
 
Last edited:

holygeez03

Enlightened
Joined
Sep 30, 2010
Messages
778
What's funny is that I was searching for a review like this last week when I was considering a K18... I went ahead and ordered one from Going Gear. I had long considered getting some 10440's to use in one of my iTP A3's, but always decided against it. Since the K18 officially supports the 10440 and has a side switch, I couldn't resist.

I agree with everything in the review above... light feels solid and looks great... clicky switch could be a weak point on a keychain light, but we will see in time... the UI is a little weird for me since I don't have another UI like it, but it should do a good job of preventing accidental activation. And it can be locked out easily with a slight loosening of the head, which stays plenty tight for carrying.

The light output is FANTASTIC with a 10440... I wouldn't mind if the lowest mode had a sub-level for an even lower mode, but based on the cost of the light and the output on high, it is well worth it. I will usually have a Zebralight with me for most needs, but when I find myself without, the K18 is a great keychain backup.

If it holds up on my keychain... I will probably order a few more for myself and xmas gifts!

If only it had a neutral option... maybe someone will start modding them???
 

magellan

Honorary Aussie
Joined
Feb 3, 2014
Messages
5,003
Location
USA
Great review. Sounds like a nice little light. Will order one and try it with a 10440 also.
 

candle lamp

Flashlight Enthusiast
Joined
Jun 16, 2010
Messages
1,572
Location
South Korea
Thanks a lot for your runtime graphs on 10440 Li-ion cell. Bela16! :thumbsup:

1. High - 1xEfest 10440 (350mAh)
S-48.jpg

.
.
2. Med. - 1xEfest 10440 (350mAh)
S-49.jpg
 

Mstevens113

Newly Enlightened
Joined
Jan 24, 2016
Messages
19
Guys can I ask exactly which 10440 battery this you tested with?

I have a Efest IMR10440 3.7v Li-Mn 350mah here and when I tried it in the light it wouldn't work at all.

And yes it was fully charged lol
 

Capolini

Banned
Joined
Aug 4, 2013
Messages
5,945
Location
Valley Forge, Pa.
Guys can I ask exactly which 10440 battery this you tested with?

I have a Efest IMR10440 3.7v Li-Mn 350mah here and when I tried it in the light it wouldn't work at all.

And yes it was fully charged lol


I used the same battery as you! One worked while the other did not until I improvised[not recommended] by removing about 2mm of wrapper at the positive end. When I charged it as I was putting it in there were a few sparks! So I put some scotch tape on it and it works! Like I said I do not recommend this.

I guess this proves that no Two[2] BATTERIES ARE EXACTLY THE SAME.AS ONE WORKED WHILE THE OTHER DID NOT! On my Olight i3E both batteries worked. That light has a RAISED contact at the positive end unlike the flat contact on the Ultratac.

I got my batteries at liionwholesale.com.

Jon said in a few weeks he will have these Efest 10440 customized w/ a button tops. As soon as the customized BT come in I will be using them.:thumbsup:


http://liionwholesale.com/
 
Last edited:

Mstevens113

Newly Enlightened
Joined
Jan 24, 2016
Messages
19
Sounds like my battery maybe isn't contacting properly then.

It's hard finding 10440's in the UK for some reason!
 

Mstevens113

Newly Enlightened
Joined
Jan 24, 2016
Messages
19
Managed to get mine working, turns out it was the plastic wrapping that comes over the positive end stopping the connection being made.

Small trim and all sorted, no sparks like you had, only the smallest of trims needed.

Good to have the 10440 option, it's like 2 lights in 1 really this thing. AAA is the practical option I tend to think I'll use mostly but for short lived giggles the nuclear option is nice to have
:laughing:
 

kreisl

Flashlight Enthusiast
Joined
Jul 5, 2012
Messages
2,241
maybe it is not real gold!! ^^^^

but it surely smells and looks like gold :paypal:
 

Sphinxxx

Newly Enlightened
Joined
Mar 11, 2016
Messages
63
Does anybody have a Trustfire 10440 battery to see if it fits in this light? They are 46.25mm long and 10.25mm wide. I just ordered the light and want to know if i can get away with the bigger cell. I will probably play it safe but if somebody can confirm that would be awesome.
 
Top