Zebralight SC600 (1x18650, XM-L) Review: RUNTIME, BEAMSHOTS, comparisons & more!

Originally posted: August 25, 2011
Last revised: August 25, 2011

Warning: pic heavy, as usual.

The SC600 is the long-anticipated 1x18650-only light from Zebralight. Let’s see how it performs …

Manufacturer Specifications:

Inside the standard eco-friendly Zebralight cardboard box, you fill find the light with clip attached, spare o-rings, and manual.

From left to right: AW Protected 18650, Zebralight SC600, Spark SL6, 4Sevens Quark 123-2, Lumintop ED20, Thrunite 2C

All weights with no batteries.

SC600: Weight 87.2g, Length: 107.8mm, Width (bezel) 29.7mm
Spark SL6: Weight 77.8g, Length: 125.5mm, Width (bezel): 30.9mm
Lumintop ED20: Weight 84.4g, Length 121.6mm, Width (bezel) 25.2mm
Klarus XT10: Weight 121.3g, Length: 144.8, Width (bezel) 34.9mm

The SC600 is quite compact, similar to other petite lights like the Spark SL6 and Lumintop ED20 – but even shorter!

The build of the SC600 is distinctive, with its relatively large head (for such a compact body). Natural anodizing is typical for Zebralight, and is in excellent shape here. There are some faint ridges or longitudinal lines in the anodizing, but this is commonly seen on natural finish lights. There is also some mismatch in the anodizing color at the tailcap (but this is again common).

Labels are fairly minimal and small, and clearly legible against the background.

Knurling is not very aggressive on the body, but does provide good grip to the tailcap. There are also finger wells and other body elements to help with grip. Screw threads are anodized for tailcap lock-out.

As always with Zebralight, the control switch is electronic in nature, and located on the head. Switch feel is slightly stiffer than most lights with this kind of switch, and the button is slightly recessed in the opening.

Light can tailstand.

Clip-on pocket clip looks and feels more substantial than typical in this class. It should hold the light securely. Note the clip is reversible (i.e. can attach near the head, point toward the tail), but you may scratch the anodizing if you try to remove and re-attach.

There is a slightly raised button on the positive contact board in the head, and all my flat-top high capacity cells fit and worked in the light.

Video Overview

NEW: Normally at this point in the review, I like to show the emitter/reflector and beamshots. But I’m trying something new out - video reviews showing both the basic build and user interface. Check it out below - beamshots will follow after the user interface and circuit discussion.

Video was recorded in 480p, 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 option.

User Interface

The SC600 uses a variant of the standard Zebralight interface. While it may sound a little complex when first described, it is actually quite easy to use.

On/off and mode switching is controlled by the electronic clicky switch. There are 9 possible output modes, arranged in 3 sets of pairs. The main level choices are Lo – Med – Hi. There are two possible outputs at each level, commonly referred to as 1 or 2 (e.g. Lo1/Lo2, Med1/Med2, Hi1/Hi2). The Hi level is where things get interesting – you have the option of 4 possible outputs for H2 (including the strobe mode – more about that in a moment).

Basic Operation

Note that the light has independent mode memory to recall your preference at each of the Lo, Med, Hi levels (i.e. always come back to the choice you last left that level in).

From Off, a quick click turns on the light to your memorized Hi. Click quickly again to cycle from Hi to Med, and Low. You need to perform these clicks rapidly if you want to switch modes this way (i.e. from Off, single-click is Hi, double-click is Med, triple-click is Lo). After about a second or so of being On, a quick click will simply turn the light off.

Alternatively, from Off, a slightly longer press and hold (i.e. >0.5 sec) turns on the light to your preferred Lo mode.

To advance from one mode to the next while the light is On, press and hold the switch to cycle through Lo, Med and Hi, repeatedly (you can do this directly from Off too). Release the switch to select the level. As before, a quick click turns off the light.

Change between output choices for a given level

Double click at any level to toggle between the two sub-levels for that level (i.e. 1 or 2). The light will memorize your choice and return to it next time you cycle or turn on at this level. The memory even lasts through battery changes.

For the Hi level, you can set the Hi2 to one of four outputs. To enter the programming feature from the current Hi2 level, double-click the light 6 times rapidly. Now, every additional double-click will advance you through the four programmable options (200Lm, 330Lm, 500Lm, or 4Hz Strobe). To select the mode you want as H2, simply turn off the light once you have made your choice. When you next turn it on, that last level will have been memorized and returned to automatically.

And that’s it – it is really very simple in practice, once you get used to the timings.


There is no sign of PWM on any of the 9 possible levels. I conclude the light must be current-controlled.

The SC600 “hidden” Hi2 strobe was measured at a fairly low 3.2 Hz frequency in my testing (i.e. more a signalling strobe than a tactical one).

Standby Current Drain

Due to the electronic switch, all Zebralights have a constant parasitic stand-by current drain when the tailcap is connected.

In this case, I am happy to report the standby current is a fairly neglible 69.6uA. For a typical 2600mAh 18650, that would translate into 4.26 years before a battery would be completely discharged.

And as always, this current can be cut by simply unscrewing the tailcap a quarter turn when the light is not in use (which I recommend for all lights with a standby drain).


And now the part you’ve all been waiting for.

The SC600 reflector has fairly typical dimensions (perhaps a little shallower than some), with a medium OP coating. This suggests the light will not be a great thrower. XM-L emitter was well centered on my sample.

For white-wall beamshots, all lights are on AW protected 18650, about ~0.75 meter from the wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences. All beamshots taken immediately upon activation.

As expected, the beam profile is fairly floody on the SC600.

Here is a 100-yard outdoor beamshot comparison to the Spark SL6, in the style of my earlier 100-yard round-up reviews:

See that thread above for more info on the terrain, on how best to interpret these images.

Testing Method:

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:

Effective November 2010, I have revised my summary tables to match with the current 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.

Well, this is impressive – the SC600 is the highest output 1x18650 in my collection at the moment. Output closely rivals the 1x26650 4Sevens X10.

As you can also see, throw is relatively low for the class and output, but still reasonable.

As an aside, Zebralight’s lumen estimate seems bang-on for the Hi1 mode.

Output/Runtime Comparison:

As with many high-output lights, the SC600 steps down in output at 5 mins into the Max Hi1 run. This can be overcome by simply clicking the light off-on again at this point (i.e. it is a simple timer mechanism). Note that like other highly-driven lights, the quality of cells is critical here – cheaper/heavily-used 18650 cells may not be able to provide a sustained current at these levels for 5mins.

The SC600 is fully regulated and remarkably efficient at all levels tested. Both of these aspects are likely due to the restricted voltage range (i.e. only 1x18650 accepted), allowing for a better optimized circuit. According to Zebralight, the larger head also allows them more room on the circuit for a larger and more efficient inductor.

End of the day, if you don’t mind the 1x18650 limitation, you get the most efficient circuit that I’ve seen to date on 18650.

Potential Issues

The SC600 doesn't take 2xCR123A or 3.7V Li-ion sources, only 1x18650.

As with other heavily-driven lights, some 18650s may not be able to handle the sustained discharge rate. I recommend you stick with high-quality cells (my AW and Redilast cells all worked fine).

Switch timing takes a little getting used, if you aren’t already familiar with Zebralight.

Preliminary Observations

The SC600 packs a lot of punch – more than any other 1x18650 I’ve tested to date, including both the Thrunite Scorpion V2 and Spark SL6. It also has the most efficient and well-regulated circuit I’ve seen in this class. Oh, and have I mentioned it’s incredibly tiny too?

That’s an awful lot to distinguish this light. Of course, as with all things, there are some trade-offs here. The high efficiency and full regulation comes at the expense of a wider voltage range, preventing you from running 2xCR123A or 2xRCR. And the compact size means you can’t get a greatly focused beam – the SC600 is more of a floody light.

The overall build, switch feel, UI and circuit functioning will seem very familiar to Zebralight owners. But as always, there are a few innovations here – like the extra selectable levels for the Hi2, additional grip elements (knurling and finger wells), and a newly designed clip. All of these are welcomed in my books, and I like that Zebralight constantly updates and expands the build/UI of their lights with each new release/model.

With all the levels and options, I find there’s something here for everyone. Well, except maybe you tactical strobe folks – but for once, I’m glad to see a maker provide a more generally useful slow signaling strobe. And no, it isn’t a great thrower, but there are other (larger) lights in this class to consider, if that is what you are looking for.

End of the day, if you want an incredibly bright, relatively floody, efficient and tiny 1x18650 light, then I think you should give the SC600 a close, hard look.


SC600 provided by Zebralight for review.

To follow the online discussions for this review, please see the full review thread at CPF.

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Page last updated on September 7, 2011 - selfbuilt (at) sliderule (dot) ca (replace the "at" and "dot" labels with the appropriate symbol for e-mail)
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