Review: Astrolux S42S 1600 Lumen Nichia 219 Flashlight

This is a review of the Astrolux S42S flashlight. It is a high-powered light that takes a single 18650 or 18350 battery. Four LED emitters, either XP-G3 (cool white) or Nichia 219C (high CRI neutral white), produce up to 2000 lumens in turbo mode. This review covers the Nichia 219C version.

The S42S has a copper head, and stainless steel body. You can get it in either funky colors, or plain. The regular S42 is an aluminum body version.

The light has 7 different mode levels, from moonlight through turbo. It also has 3 hidden flashing modes. It can be programmed with or without mode memory. A single electronic switch controls all functions.

The light was provided by Banggood for review purposes. You can find the S42S light on their site here, along with further details:

Astrolux S42S

There is a discount code which brings the above light down to $38.95. Use code 859e1c.

There is also a video review of the light I put up on youtube, here:

Overview:

What is better than a flashlight that uses a Nichia 219 LED? A flashlight that uses 4 of them, of course!

The Astrolux S42S is well constructed with copper and steel, and feels good in the hand. It comes configured as an 18350 light for compact size, though I recommended getting the 18650 extension tube for better run times. As an 18650 light, it isn’t that much larger, and you get almost 4x the capacity of an 18350 battery. If you do decide to use it as an 18350 light, get a good battery, such as the new high-drain/high-capacity Aspire 18350 cells.

The Astrolux S42S has built-in micro USB charging. You can charge your cells externally if you wish, but I find the internal charging works very well and is convenient, especially for topping-up. Termination voltage is 4.18v.

The light uses 4 LED emitters to achieve the high brightness. The cool white (6500K) version (2000 lumens) uses 4 x XP-G3. The neutral white (5000K) version (1600 lumens) uses 4 x Nicha 219C. This is a very floody light. More floody than traditional single-LED lights. So, while output is impressive, it will not throw long distance. It’s great for intermediate distances, out to around 100 meters.

As a self-confessed tint snob, what can I say about the Nichia version? Perfect tint, even color across the entire beam, absolutely no green hue, and high color rendition. You can’t do better in LED lighting. If you get this light, get the Nichia 219 version. You do lose 20% in brightness, but you gain so much more in accurate color rendition. And at 1600 lumens (yes it really is that bright on a fresh battery), it’s still plenty bright!

I believe this light uses a FET driver, so getting maximum output depends on a good battery. A high-drain 18650 cell will give you the best performance. I actually measured 1800 lumens on a freshly charged cell, seconds after it was put on turbo. However, as the battery drains, so does output on the higher levels. On a half-depleted battery, output is closer to 1000 lumens.

Be aware that the light gets hot fast at full output. However, it also gradually reduces brightness rather quickly (down to the High 2 mode after 1 minute), so it doesn’t get burning hot. The turbo shold be thought of more as a boost mode, not to be run continously for very long. And since it can suck up almost 10 amps from a fresh high-drain cell, you wouldn’t get much run-time on turbo anyway.

Copper and steel make this light heavier than aluminum lights. It feels good in the hand, has good grip, and carries fine in a pocket with the included clip. I would not EDC this light without the clip, due to it being somewhat large and heavy. Fully loaded, with 18650 extension tube and pocket clip, and a battery installed, it tops out at 246g. It’s well balanced, so it doesn’t feel that heavy.

Strangely, this light also comes with a steel spike that can be screwed into a tripod hole at the bottom of the light. It is referred to as a hammer, but I’d hate to try hammering anything with it. I think it’s really meant as a glass breaker. So, this would be a useful configuration if you want to store the light in your car for emergencies. The tripod hole might also be useful to someone using this for lighting. Otherwise, it’s an accessory you will probably never use.

Modes: moonlight, low, medium1, medium2, high1, high2, and turbo. Also, 3 hidden modes: stobe, bicycle strobe, and battery-check. The light has mode memory if used in a 4-mode config, in regular configuration it always starts in moonlight.

LED: 4 x Nichia 219C 5000K neutral white. Or 4 x XPG3 6500K cool white.

Lens: anti-reflection coated. Protected by steel bezel.

Size: 110mm long (18650) or 80mm (18350), 27mm diameter.

Weight: Up to 246g with 18650 config and pocket clip and installed battery.

Construction: Copper head, stainless steel body. Drop-proof (1.5 meter). Water resistent IP65. Good grip on body. Threads are nicely cut, and came lubricated. Space on tail for a lanyard (included). Feels very solid and well built.

Battery type: Flat-top unprotected 18350 or 18650. There’s a bit of room for short button-tops, but a protection circuit would make cells too wide or too long. And since this benefits from high-drain cells, a protected battery would not give good results on turbo.

Over-discharge protection: yes. The light will drop to moonlight mode, and blink every couple of seconds, when the voltage drops to 2.9v. At 2.8v, the light will shut off.

Output: From a moonlight of 1 lumen, to a turbo of 1800 lumens. 7 different modes, details later in this review. Note that output drops as your cells deplete, due to this using a FET driver.

Beam profile: Floody light.

Heat: Gets hot quickly on turbo, but reduces output within 1 minute to high2. Fine to hand-hold on high2.

Tint: 5000K netural white, high CRI. Perfect!!!

PWM: I’m sure this must use PWM to regulate output with the FET driver on some of the modes, but it must be very high frequency. It shows no signs of PWM.

Tail-stands: yes.

Standy drain: 15uA if locked out. (Very good!) 0.95mA if on with pulsing switch LED. Don’t leave it like this for weeks, or it will drain your battery. Instead, lock-out the light with a long-press.

Operation:

There are 2 mode groups. See Banggood’s web page for details.

Basically, you click to turn on (moonlight), then click to advance modes. It cycles back to moonlight after turbo. Press&hold to turn off.

Hidden modes (strobe, bike strobe, and battery check) are accessible by a long-press from moonlight.

If you double-click, you will enter a 4-mode group, that uses mode memory. Double-click to revert back to the regular group.

The light features a pulsing green switch LED, for locating it in the dark. To turn this off and lock out the light, press & hold from off. To unlock the light, press & hold again.

My impressions:

Pros:

- Very bright for a 1x18650 (or 1x18350) light. Sends out a wall of floody light.

- Excellent tint and beam profile with the 4 x Nichia 219C LEDs.

- Built-in micro USB charging.

- Well contructed and tough.

- Pulsing switch makes the light easy to find in total darkness.

- Locked out it has very low standy current.

- Moonlight mode is a nice feature to have. (Though 1 lumen is fairly bright for moonlight.)

- Supports 18350 and 18650 battery types.

Cons:

- The FET driver means that a constant output (especially on higher outputs) is not possible. It allows for really high output, but only with fresh cells.

- Turbo heats up fast (understandably), so it steps down quickly.

The following two pictures illustrate how the light performs outside. This is approximately what I see with my eyes. The first image shows a Zebralight (a standard EDC fairly floody light) with an output of 300 lumens.

Next, is the Astrolux S42S at 1600 lumens. It obviously lights up much better, but it is also more floody so lights up a much wider area. The trees are approximately 40 meters away.

Here are two beamshots of the same lights as above.

And a beamshot of the S42S alone:

The contents contain the usual extras, clip, lanyard, o-rings, manual, and a spike. Okay, maybe the spike isn’t “usual”.

Several pictures of the light’s parts. Head, body tubes, the spike, the tailcap.

Here are images of an 18650 battery installed. It protrudes about 2mm, but the spring in the head compresses to fit it easily. Long protected cells would not fit, and would not be appropriate for this high-drain light anyway.

Finally, here are some pictures showing the micro USB charging port, and the LED indicator.




That’s all for now. Thank you for reading.

Pictures don’t seem to be showing up. Looking into it…

My bad… fixed now.

Thanks for the nice review!

I see that the s42s that you review has the improved USBport cover, does it also have an improved user interface, especially does the long-press-for-off still not work on the moon-setting (which is the first setting you enter when switching on the light), so you can’t switch off the light while on moon, but instead the light goes to turbo?

I think the user interface is exactly the same as before. I believe they fixed the USB port and battery length issues on both the regular (aluminum) version and the stainless-steel model. You’re correct, that a long-press from moonlight goes to the special turbo/strobe/battery check modes. That’s the only mode in group 1 that acts differently. You’d have to be in mode group 2 for all long-presses to turn off the light.

I think the intent is to give the user a quick way to get to turbo. i.e., turn on the light, then long-press for turbo. But it’s not obvious unless you read the user interface diagram. I got used to it after a a couple of days, but it’s not like my other lights. Usually, it’s a double-click or triple-click to get to turbo or special modes, on other lights.

My preferred user interface is Zebralight’s, but that’s just my personal preference. The S42 interface reminds me a lot of Manker’s user interface.

As previously noted here, the UI appears to be a failed attempt to adapt the BLF A6 UI (designed for clicky switch, and used in the Astrolux S1 and S41) to an electronic pushbutton switch. Besides being unwieldy at times, some of the original features (like both forward and backward stepping through brightness levels, and the ability to power down from anywhere) simply could not be implemented.

Yes, the user interface does seem to be an electronic version of the BLF A6, without the back-stepping.

When in moon , to go to standby I give a short press to the next mode and then a long press or unscrew the head a little and back.

The USB cover could be better if the new bit they added was not loosely fitting in the metal female USB.

Yes, as long as you remember that the moon mode is a bit special, then it’s quite simple. I don’t find it much of a problem, because this isn’t a light I’d use in moon mode very much.

I don’t find it loose fitting in mine. It fits fairly tight, once you close it and push it in. It’s certainly not waterproof, but stands up fine to rain, etc.

I don’t think I’d want a USB port on all my lights, but it’s a handy feature on some lights. I think it’s useful on this light since it uses a FET driver for maximum output. It’s handy to use the USB charging to keep the light topped up for maximum performance. Once the battery level drops about half, the light output drops to more traditional 1x18650 light levels, and topping it up before that keeps the “wow” factor when using turbo.

I bought both the colored version and the stainless steel and copper version back in 2018. But the USB port covers fall off easily, and when on they don’t stay put. So in my opinion they have not fixed the USB port cover very well. If there is a colored version with a good USB port that stays put, I’d buy another cause I really like this light. Is there one?