The light was supplied by Banggood, no compensation other than the light itself was received for this review

The price can be lowered to 25.95$ with Mad Max coupon here

This is my 3. light that was supplied by Banggood for a review, I am honest and will judge the light as it is with its pros and cons

I have now a Narsil driver designed and build those, great UI compared to the stock one
Sale topic here http://budgetlightforum.com/node/56618
The old MCU is one side disconnected to get rid of 1mA parasitic drain

Specification:

Product name: Astrolux S42 2023LM Rechargeable Mini LED Flashlight
Brand: Astrolux
Model: S42
Emitter Type: XP-G2,XP-G3, Nicha 219C
Light Temperature: XP-G2(6500K),XP-G3 (6000-7000K),219C(5000K)
Light Color: Cool white,Cool white,Warm white
Material: Aluminum alloy
Total Emitters: 4X
Mode: Group1:Moon,Low,Med1,Med2,High1,High2,Turbo
+Moon,Turbo,Tactical strobe,Battery check,Bike flasher (without memory function,short press<0.5s)

Group2:Low,Med2,High1,High2 (with memory function,duble click the button,short press<0.5s)
Lumens: 2lm,20lm,140lm,240lm,545lm,735lm,2023lm (XP-G3)
1lm,17lm,125lm,220lm,490lm,650lm,1740lm (XP-G2)
1lm,16lm,125lm,210lm,475lm,630lm,1630lm (Nichia 219C)
Runtime: 2.9D,1.3D,6h,2h,1h,0.4h,0.39h (18350)
14D,6.4D,29h,9.7h,4.8h,2h,1.99h (18650)
Battery Configurations: 1 x unproteced plate head 18350/16340/18650 battery (not included)
Working Volatge: 2.8v-4.25v
Switch Type: Clicky
Switch Location: Body side of the flashlight
Peak Beam Intensity: 19850cd
Impact Resistant 1.5 meters
Max Output: 2023lumens
Waterproof: IPX-65 waterproof
Body Color: Black
Weight: 60g (without battery)
Size: 77mm x 27mm (length x head diameter) (18350 size)
102mm x 27mm(length x head diameter) (18650 size)

There is an error in the original specs the Nichia are neutral white, while they are described as warm white

for more manufactory product pictures go the Banggood

the parcel arrived after 36 days shipping with to Germany which is acceptable from China.

Package and content:

The light came packed well with a plenty wrap around and in a plastic bag

The light comes in a card box which is typical for Astrolux

The box has a compartment for the light and a battery, but the battery compartment has 14500 size while it is a 18350/18650 light

It comes with 2 spare o-rings, clip, lanyard, spike, thread adapter and manual

Here you can see the optional 18650 tube with clip attached, compared to an Utorch UT01, which looks quite familiar as this light

Photos of the light

Comparism and teardown:

Size compared to other 18350 and 14500 lights


I would have dropped the thread for the spike in the tail cap to get the light shorter

compared to 18650 lights


there is a 18650 aluminum tube available, but it is as well too short for button top or protected batteries, probably a longer 18650 will be released soon for the S42

Beam color is neutral around 5000K for the Nichia 219C model, the Nichia has a nice uniform beam and color rendering is great


The LEDs are perfectly reflowed and the MCPCB sits perfect, but the charging port cover slips too easily

from left to right the lights get warmer, picture taken @5000K camera setting

left XML2 U3-3D 5000K, Astrolux S42 Nichia 219C 5000K, Nichia 5000K, XPL HD 1A 6500K

The LEDs in this light are available in XP-G2, XP-G3 and Nichia 219C

The light can be taken apart completely, nothing is glued

The light has the tail cap with a thread for the spike or an tripod

The head has a diameter of 27mm and 21mm visible of the TIR optic

The driver can’t be pulled out easily, the LED leads have to be unsoldered
I highly recommend unsoldering the side switch board as well
then push the driver out through the LED wire hole

The driver board has 2 pads for AMC7135 chips which are not populated

So a single FET is controlling all modes

the leads are all reinforced with some glue

The light can be physical locked out by twisting the tail cap or head

The Head

the TIR is a medium flood, gives a nice uniform beam with some spill

the Nichia LEDs fit in nicely

The slave board for the switch has also a green and red LED

The shelf is about 1mm thick, it could be more, but the thick copper MCPCB does a good job spreading the heat, on Turbo the head gets hot really quick, so the thermal path is well

Waterproofness might be an issue as the USB cover gets very easy loose, they should have made the cut out 1mm deeper like the Klarus lights and have the rubber cover with o-ring like shape

The thermal paste was applied in a moderate quantity and seems to be some silver compound, when I removed the MCPCB I saw a really nice pattern which means it was on the full surface and in a thin layer

The MCPCB is s true copper DTP one about 1.5mm thick, very nice, the back of it is gold plated
The MCPCBs back is perfectly flat

The lens is AR coated glass

I would like to see the TIR attached to the lens with optical glue to get more OTF lumens

Tube and Tail

Tail cap spring is thick and seems to be some alloy which is barely magnetic possible stainless steel, also the driver one is barely magnetic

I cut the tail spring a bit shorter as my unprotected brass button cell get dented in the tail, when fully screwing the tail down, even with raised top cells like Sanyo 18650GA it’s a tight fit
The light is build for unprotected batteries, protected or button top unprotected won’t fit
from those batteries only the 2 left fit without a problem

the tube inner diameter is 19mm, the springs get fully compressed with an unprotected flat top cell, so their resistance is very low, the tail spring sticks a bit over 1mm inside the tube

The tube threads are triangular cut on both sides, the tube has 2 o-rings and the tail side is lubed for water tightness
square cut would be nicer, but all Astrolux lights have triangular which fits each other

Driver and Battery

The light is USB chargeable with micro USB connector

The Light charges the battery with 0.5A
the cell reaches fully charged 4.16V, this is a safe and good value

The light has PWM in moon and medium/high modes, but it’s really fast about 100kHz hard to photograph

The light does all modes over the FET, so they are not constant, the driver has 2 unpopulated 7135 pads, it would be better to get low modes realized with regulated current

The lights runs 20 seconds on highest level, I can’t see a significant drop in brightness during that time but the head gets hot really quick from 25°C to about 60°C with a fresh cell,
then it ramps down slowly to High2, no hard step down so smooth you did not even notice
The light has no much mass to absorb heat, in turbo mode on a high drain cell it gets hot quickly, in High2 the temperature stabilizes on a good level if held in hand

If the light is left alone ceiling bounce at High2 the lights head reached a bit less than 80°C after 10 minutes @25°C room temperature, too hot to touch but technically a safe level

tail cap current measurement on brightest level
stock light:
- 6.1A with 5 year old Samsung 18650-26F
- 9.95A with new Samsung 18650-30Q
- 8.90A with new Sanyo 18650GA

Tail current for other modes
Moon 6.9mA
Low 79.5mA
Middle1 0.6A
Middle2 1A
High1 1.47A
High2 2.12A

The mode spacing is too close together for my liking, the moonlight could be lower like a firefly using those unpopulated AMC pads on the driver

At 2.78V the light does step down to firefly mode and blinks low voltage warning
if the battery voltage recovers you may enter low and middle1
Below that voltage it shuts down and you cant turn on the light again

The light pulls in the breathing mode 0.95-1mA from the battery
Unfortunately the breathing mode runs down to 2.38V which is too low, and will damage the battery

When the light is locked out with side switch it pulls about 15uA

Modding:
The only thing I will do when I get time would be getting a Narsil driver installed

driver replacing without keeping the chargin circuit is easy, a 21mm driver fits with minor sanding

with AWG18 and SIR800 FET pulling 18.9A on cold start
instead the 9.95A with fresh Samsung 18650-30Q cell

I went with a solution I like, keeping the old drivers slave board electronics with charging

I did wire the old electronics with the LED+ wire on the star, so if I want deactivate the USB charger and breathing lighted sideswitch to get rid of the parasitic drain,
I can unsolder the thin wire on the star

The drivers contact board and TA 21mm LDO driver

trimed the board to fit easily

used my Dremel to get rid of unsoldering the leads to the switch board

trimmed the old driver contact board to fit inside the head, cut the bolts connecting both boards by 4mm and sanded it

Driver assembly before gluing the old board on top of the TA driver to fix the position USB slave board
I had to cut the USB opening a bit as I trimmed not enough leng of the bolts

The lead connecting the old slave board with the battery, can be easily disconnected

I did just cut the tail spring a bit shorter to allow my brass button flat tops to fit without denting the battery bottom,
there will be longer tubes released soon

Beam shots

about 2m from Light to ceiling
Astrolux S42 Nichia 219C

Astrolux K01 XPL-HD 3D

Jetbeam Jet-1 MK modded with Nichia 219C from a BLF348-2016

Utorch UT01 6500K

Nitecore P12 XML U3-3D NW

User Interface

I don’t like how long it takes pressing the button to shut the light off, my Utorch UT1 is a lot quicker, also when in moon mode a long click goes to turbo instead shutting the light down, which may ruin your night vision

I like the user interface of the UT01 more than the one here

The double click to switch mode groups is wasted, better do instant turbo from any mode and off with it and switch modegroups differently

Conclusion

Positive:
- good production quality
- solid head, DTP star screwed on the shelf
- Nichia LEDs has a nice neutral white with great color rendering
- AR coated glass lens
- good floody beam, but also some throw by the amount of light on turbo
- build in USB charging CC-CV tops at 4.16V with max 0.5A charge current

Neutral:
- original 18350 tube is too short, the new tube is longer and fits button tops without any problem, however protected ones are still very tight
- triangular cut threads with good quality, square cut would be nicer
- the UI is not really good, but useable for normal users
- S41/S42 18650 tube fits only unprotected flat top batteries
- low and medium modes running over the FET, so they get dimmer with lower cell voltage
- beam profile can be better if the TIR would rest on the LEDs, can be modded
- first USB cover gets very easy loose, they offered to send a new one which fits a lot better

Negative:
- the low voltage protection in breathing mode the light runs the battery way down too much to 2.38V
- UI is bad for enthusiats