The SL02 is a budget light that runs off a 18650 or 18350 battery, using the included body tubes and cells. Also includes auxillary RGB modes in the head and tailcap.
- Manufacturer Specifications
- Package Details
- User Interface
- Circuit Measures
- Emitter Measures
- Testing Results
- Pros and Cons
- Overall Rating
- Preliminary Conclusions
Mateminco is another new “budget” light maker that I’m become aware of since my return to reviewing. The SL02 is a new every-day-carry (EDC) model that they have recently released. It features a Lumileds HL2X as the main emitter, and auxillary Osram RGB emitters.
It also comes with both 18650 and 18350 Li-ion batteries, and body tubes to accommodate the two lengths. This is nice feature, as it adds flexibility in how you can carry. Plus it is comes with integrated charging, which is very convenient.
Let’s see how it performs in my testing.
Note: as always, these are simply what the manufacturer provides (although in this case, specific to my custom specs). Scroll down to see my actual runtimes.
|Emitter||Lumileds HL2X + Osram GWJTLMS1.EM|
|Tint||Cool + RGB|
|Max Output (Lumens)||1,287|
|Min Output (Lumens)||10|
|Max Beam Intensity (cd)||50,850 cd|
|Max Beam Distance (m)||451 m|
|Weight (w/o battery)||75 g|
|Weight (with battery)||-|
|Head Diameter||26.8 mm|
|Body Diameter||25.8 mm|
The packaging for the SL02 is pretty decent for a budget brand. The hard cardboard box has a fairly minimalist style (although I did find the “Adventure” pictogram amusing – I don’t know a lot of people who fence these days). Inside, the light and accessories are well packaged in cut-out foam. Included in the package:
- Mateminco SL02 EDC (in Green in this case)
- 18350 body tube
- 18650 and 18350 Li-ion batteries (unbranded)
- Pocket clip
- Wrist lanyard
- 2 Spare body tube o-rings
- USB charging cable
It’s a nice package – especially considering the low price.
From left to right: Vapcell F38 18650 (3800mAh), Skilhunt 18650 (3500mAh), Armytek C2 Wizard Pro Nichia, Acebeam E70 Mini, Skilhunt H300, Emisar D1, Mateminco Sl02, Armytek Doberman Pro.
The body design of the SL02 is pretty unique. It comes with both a 18650 and a 18350 body tube, but the tubes are completely enclosed at the head-end. The reason for this soon becomes apparent – there is a USB-C charging port on the screw threads on the head-end of the body tubes. This means that you need to take the head off to charge the light, and so need to have the battery fully enclosed inside the tube with the tailcap in place.
The light tailswitch functions as a reverse clicky switch (i.e., you need to click-and-release for the light to turn on, scroll down for a description of the user interface). Feel and traverse of the switch is pretty good for the clicky action, a bit firm but decent. It’s a little harder to reliably flash the switch to switch modes (i.e., partial press), as you need to press it firmly enough that it might accidentally click off. But you can also rapidly click off-on to advance modes, so that does work just as well. Again, scroll down to see the user interface.
Screw threads are bare aluminum, with no anodizing at either end of the body tube. This means that there is no way to physically lock out the light. This is a surprising design nowadays. My best guess is that they were concerned about the charging current having to flow through the switch, and so they left the threads bare as an alternate current path.
There is no knurling on the light per se, just a couple of cut-outs and some ridge details on the head. This could make the light a bit slippery, so I recommend you use the wrist lanyard or pocket clip. The clip has the added value of helping stop potential roll of the light too. Anodizing looks to be good quality on my sample, for presumed type II (given the green colour). I would describe the finish as satin.
The batteries that come with the light are not branded, and seem like typical budget cells. The rated capacities listed on the wrappers are rather low, at 2600mAh and 1200mAh respectively for the 18650 and 18350 cells.
The tailcap is perfectly flat, and the switch cover is recessed just enough so that the light is able to tailstand fairly stably. There is a cut-out on the side of the tailcap for the wrist lanyard.
What is very distinctive are the RGB emitters in the clear surround of the tail switch cover, which slowly cycle through the output colours. These are actually on at all times when a battery is connected (although it turns off if you click the switch for the main emitter). The output is low – it is clearly meant as a “find me” feature for the light in the dark.
I was surprised to see these RGB emitters were actually on when I opened the box – the light doesn’t ship with a lock-out paper or plastic disc. This strikes me as a safety concern, as the light could in theory activate inside the box. It also means the battery could drain while stored in the unopened box. Scroll down to see a discussion in the circuit measures section of my review.
Here is a video of the slow cycling pattern of RGB tail cap:
Here are some stills, showing the various colours. Again, the emitters aren’t very bright, and so the current draw is fairly low. I’ve also found that the emitters to shut-off when the battery charge is low. Again, scroll down to circuit measures section.
The head of the light is also interesting. There is a distinctive looking optic that actually focuses the hotspot fairly clearly while diffusing the spill. There is a stainless steel bezel ring holding it in place, which is fully flat (i.e., no crenelations).
I have to say, that is a pretty distinctive optic. The main beam pattern is thus a combination of centre-beam throw and wide diffuse flood. Scroll down for actual outdoor beamshots.
But there is also a series of RGB emitters in the head as well. These are activated by clicking the switch (i.e., they are on the main sequence of output modes). Like the tailcap, these can only be activate in a continuous cycling mode (i.e., can’t select specific colours). But unlike the tailcap, these run in a far faster cycle, more of a “disco” mode, as shown in the video below.
Again, here are a bunch of stills showing some of the individual colours, as best I could capture given the rapid speed.
The SL02 uses a very straightforward interface, as described below.
- Soft-press: Nothing.
- Press-and-hold: Nothing (light functions as a reverse-clicky switch, have to release to turn On)
- Single-click: Turns On in last memorized mode used
- Double-click: Turns On and then Off (i.e., individual clicks simply turn the light on and off).
- Single Soft-press: Advances to the next mode in the following sequence: RGB – Lo – Med – Hi
- Double Soft-press: Jumps to Strobe mode
- Press-and-hold: Turns Off (as it functions a reverse-clicky)
- Single-click: Turns Off
- Double-click: Turns Off and back On, and advances to the next mode (i.e., a rapid series of clicks works the same as repeated soft-presses).
Yes, the circuit memorizes the last constant On output level as long as you leave it on for >2 secs. Any faster, and repeated off-on clicking simply advances modes.
Yes, a single typical strobe mode (scroll down for measures).
Low voltage warning:
Not that I have noticed.
Not that I can find. Note that the light lacks anodized screw threads, so this means it is always drawing a standby current (scroll down for measures). Furthermore, the tail RGB emitters are always active, slowly changing colours when a battery is present inside the light. There is no way to physically or electronically lock-out the light.
This is a fairly basic but serviceable interface. I’m not happy about the front RGB “disco” mode being in the main sequence, and there is little to differentiate Med and Hi visually (scroll down for testing measures). But at least Strobe is hidden behind a rapid double-press of the switch.
My main concern is the lack of the lock-out, and the constant slow-cycling RGB in the tailcap. However, this current is minuscule (see below), and the tail RGB emmitters do shut-off once the battery runs down to a low voltage.
Pulse-Width Modulation (PWM):
There is no sign of PWM, but there is high-frequency circuit noise on the Med and Hi levels at ~5.1-5.2 kHz respectively. This is high enough to not be visually detectable.
Strobe is basically ~11 Hz by default.
I measured the initial charging current when the cell was <3.0V as 1.1A, but it quick drops down to ~1.0A by the time the cell reaches ~3.0V. This differs from a number of recent lights that start at an initially low level and jump up to a high current – the SL02 starts at a decent current and drops slowly as the battery charges. Note that a 1A initial rate is quite reasonable for a 18650 cell, but I find it a bit high for the 18350 cell.
You can notice a red LED on the head of the body tube, indicating charging has started. Of note, the manual says you need to click the tailcap into the On position for charging to work – but this isn’t required on my sample. And I’m not surprised by that, given the non-annodized threads (i.e., switch status should be irrelevant).
One quirk that I noticed – the LED shows green by the time the charging drops to ~0.2A.
At this point, I stopped the charge and measured the resting battery voltage as only ~3.85V. So I reconnected and let it run until it seemed to stabilize at ~0.02A.
As this level, the battery was reading only ~3.95V.
At this rate, I’m hard pressed to imagine the cell ever reaching or exceeding ~4.0V with the built-in charger. While a nice feature to include (especially for the price), you are better off investing in a proper charger if you want to fully charge the cells to ~4.2V.
Standby / Parasitic Drain:
With the tail RGB LEDs on and cycling, I measured the standby drain for the tail switch as a low ~150uA. For the included 2600mAh 18650 that would translate into just under 2 years for the battery to be fully drained. And for the 1200mAh 18350, just under 11 months (assuming fully charged to start). This is surprisingly good for continuously emitting and cycling coloured LEDs.
As previously mentioned, there is no way to lock out the light at the tailcap, due to the non-anodized threads.
In this section, I directly measure key emitter characteristics in terms of colour temperature, tint, and colour rendition. Please see my Emitter Measures page to learn more about what these terms mean, and how I am measuring them. As tint in particular can shift across levels, I typically stick with the highest stably regulated level for all my reported measures.
As explained on that page, since I am using an inexpensive uncalibrated device, you can only make relative comparisons across my reviews (i.e., don’t take these numbers as absolutely accurate values, but as relatively consistent across lights in my testing).
SL02 on Med:
The key measures above are the colour temperature of ~5590K, and a noticeable positive tint shift (+0.0140 Duv) to greenish-yellow at this temperature. For CRI (Ra), I measured a combined score of 61.
These results are consistent with the specs, and other emitters in this class.
All long-distance outdoor beamshots are taken on my Canon PowerShot S5 IS at f/2.7, 1 sec exposure, ISO 400, daylight white balance. The tree at the centre of the hotspot is approximately 90 meters (~100 yards) from the camera. Note the road dips down and turns away in the distance, out of the camera’s sight line. Learn more about my outdoor beamshot locations here.
Click on any thumbnail image below to open a full size image in a new window. You can then easily compare the overall beams by switching between tabs.
As you can see above, the SL02 produces a relatively focused hotspot, with wide (but dim) spill. Overall output is of course lower than the higher output emitters above.
My summary tables are generally reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. In addition to the links above, please see my output measures page for more background.
All my output numbers are based on my home-made lightbox setup. As explained on that methodology page, I have devised a method for converting my lightbox relative output values to estimated lumens. Note that my lightbox calibration seems to run higher than most hobbyists today, but I’ve kept it to remain consistent with my earlier reviews (when the base calibration standard was first established).
My Peak Intensity/Beam Distance are directly measured with a NIST-certified Extech EA31 lightmeter.
SL02 Testing Results
|Mode||Spec Lumens||Estimated Lumens @0sec||Estimated Lumens @30 secs||Beam Intensity @0sec||Beam Intensity @30secs||Beam Distance @30secs||PWM/Strobe Freq||Noise Freq||Charging Current <3V||Charging Current >3V||Parasitic Drain||Weight w/o Battery||Weight with Battery||CCT (K)||Duv||CRI|
|Low||10||0.20||0.20||-||-||-||No||-||-||-||~150 uA||74 g||119 g||-||-||-|
|Mid||550||470||460||-||-||-||No||5.1 kHz||-||-||~150 uA||74 g||119 g||-||-||-|
|High||1,287||1,400||1,200||10,900 cd||7,600 cd||174 m||No||5.2 kHz||-||-||~150 uA||74 g||119 g||5,585||0.0138||61|
|RGB||10||0.90||0.90||-||-||-||No||No||-||-||~150 uA||74 g||119 g||-||-||-|
|Strobe||1,200||-||-||-||-||-||11.2 Hz||No||-||-||~150 uA||74 g||119 g||-||-||-|
Beam pattern is relatively throwy, but nowhere near the beam specs (which are completely unrealistic for a light this size).
Output levels seem reasonably consistent to my lightbox measures for Med/Hi (noting that my lightbox calibration is generous), but the Lo/RGB are clearly much lower than the specs. Indeed, the Lo mode is actually a <1 lumen Moonlight in my testing.
These level spacings don’t really make a lot of sense to me – jumping from 0.2 lumens to 460 (Lo to Med) is too big a step. And there is little visual difference between 460 and 1200 lumens (Med to Hi) in practice. They would have been better off with a fourth true Lo level (in ~30-40 lumen range), and/or a reduced Med mode.
To view and download full testing results for all modern lights in my testing, check out my Database page.
The SL02 is presumably using a linear driver, given the apparent direct-drive pattern above (i.e., the circuit is not flat voltage-regulated). Overall efficiency seem reasonable, especially given the lower rated capacity of the bundled 18650 cell. Runtime performance is similar on the bundled 18350 cell, as shown below.
There is a step-down on Hi, as shown below for the 18350 run:
This performance is reasonable for the actual output levels, but see my comments above for recommended output level spacing.
|In-light charging included, but it requires you to remove the head due to the screw thread placement.||Mode spacing is unusual, with no real Lo (Moonlight instead), and a Med mode that is not visually that different from Hi.|
|Circuit is not flat-regulated, and seems to be direct drive. Overall efficiency is reasonable for the class though.||RGB "disco" mode on the front emitter is part of the main sequence, and cannot be hidden.|
|Beam pattern is relatively focused for throw, with wider and dimmer spill than typical thanks to the custom TIR optic (although the specs are completely unrealistic).||No ability to lock out the light, or disable the rear tail RGB emitters (which slowly rotate through output colours).|
|Tailcap RGB emitters provide a low-output "find me" feature for the light||In-light charger terminated early at ~4.0V in my testing.|
|18650 and 18350 batteries are included (but are no-name cells).||Reverse clicky switch is a bit stiff for mode changing.|
The SL02 has a lot of distinctive features. Overall, it’s a pretty good package (especially so for the price), with a lot of versatility. That said, it belies its budget nature through many of the specific design choices, and their consequences.
Starting with the build, the tailcap design has a unique “find me” feature with slowly changing low-output RGB emitters. However, the lack of anodized tailcap threads (likely required by the in-light charging design) means there is no way to deactivate this feature without removing the cell.
I find the enclosed body tube chambers to be a distinctive build feature. Again, this is presumably required by the unique in-light charging design (i.e., the charger port is on the screw threads, so you need a way to close the chamber). However the charger terminates early in my testing (at ~4.0V). So it seems like these two unusual design choices were driven by a feature that is, ultimately, of somewhat limited usefulness.
For all that, the build seems solid enough, and well put together. It is also nice that they included both a 18350 and 18650 battery (especially at this price). But I’ve had a lot of bad experiences with cheap cells, and so I recommend you replace them with a quality brand name.
The beam pattern is distinctive, with its unique optic and uncommon emitter. Throw is good (but nowhere near the published specs). Output level spacing is not particularly well thought out in my view, and the user interface is very basic (with the front-facing RGB’s rapid-shifting mode as part of the main sequence). But actual output/runtime performance of the light is pretty good, thanks to the linear driver and efficient direct-drive pattern (fans of flat-stabilized output will need to look elsewhere though).
So, a mix of decent features and build, but with limitations. If you like the RGB features, that might make this more compelling for you. It’s certainly a pretty cool and distinctive optic. But personally, I’d prefer if more attention were paid to the user interface and main beam output levels.
The SL02 was provided by Mateminco for review. As always, all opinions are my own and the light received the same rigourous and objective testing as all other lights that I have reviewed. At the time of review, this light retails for ~$30 USD (~$40 CDN) shipped. You can purchase it directly here or with free shipping here.