Xtar TZ58 pre-production
Xtar has made flashlights, batteries and chargers for some time. In this review I am looking at the pre-production model of a tactical 18650 light. The light uses a ring to select between high-low-strobe and has a forward tail switch for on/off. The light is made of aluminum with hard-anodized (Type 3) finish.
I got the light without any box or accessories.
The light uses a smooth reflector with a XM-L led.
The head has some groves that can be used for grip. The ring only has 3 positions, each 120 degrees apart, there is an unmarked off between each position. I would have preferred the positions placed closer together and requiring less turning off the ring.
A look at the head from the backside shows the spring used for battery connection.
The battery tube has square threads and uses o-rings for sealing. There is no anodized on the threads, i.e. it is not possible to lockout the light.
The battery tube has knurling with some groves in.
On the tube is a removable clip.
The clip is locked by the tactical ring, here I have removed the ring and the clip can also be removed. The ring has a hole for a lanyard
The forward switch on the tailcap is easy accessible. Inside the tailcap is the classic construction with a spring.
Here is all the part the light can be disassembled in without tools.
This light has a very easy to use user interface and a minimum of settings (I would have prefered at least one more brightness setting and less turning on the ring). The shape with knurling and tactical ring gives a very solid grip on the light, it will not slide out of your hand.
Technical specification and measurements
The light is rated for use with one 18650 or two 16340 LiIon battery, it can also be used with an extender and two 18650 batteries (This extender will be included with the production model).
Measured size and weight:
Length: 161 mm
Diameter: 25.4 mm to 40.2 mm
Weight: 219 gram with AW18650-26
The light uses a Cree XM-L led.
In the above table I have collected all modes with both 1 and 2 batteries. All the estimated runtimes are with a 2600mAh LiIon battery. The estimated lumen is scale from the specified maximum of 850 lumens.
Note: Xtars runtime specification is with a 3100 mAh battery.
The first voltage sweep is done in high mode. The light has good stabilization down to about 4 volt, then the brightness starts dropping.
Low need slightly more volts to keep stable output.
It is easy to see on the runtime that a single 18650 is not stabilized and 2x16340 has a very short runtime. CR123 does not really have enough power for the light, but because the current consumption drops with lower voltage, they can keep the light running for a long time at reduced brightness.
The thick curves near zero brightness is the light flashing, it is probably because the battery recovers when the light goes out and then the light can turn on again.
To see how this light handles the heat, I did a run on my test bench with a temperature sensor on the light. The light has a nearly stable current, independent of temperature. The drop in brightness is due to heating of the leds, this is normal and the leds are rated for it.
Note: My test does not simulate actual usage conditions, but are done on a test bench with only the head of the light and no cooling airflow, i.e. the light will get hotter than during normal use.
The strobe is 9.8 Hz and has a 50% duty cycle. It runs at full brightness.
The light uses pwm at 980 Hz for low brightness. This is high enough to be invisible in normal usage.
When running at high the pwm is not completely disabled, there is a small trace of it left.
Comparison to other Flashlights
Xtar TZ58, Fenix TK21, ThruNite Scorpion:
ThruNite TN11, Olight M21-X, Klarus XT10:
For the full comparison to other lights with graphs and beamshots see here:
The light was supplied by Xtar for review.
Xtar has not finalized the driver yet, this means that the final light may have better performance than my measurements shows.