Well, it’s at the borderline, if we assume he put a hot light (with equalized pressure) into cool water. The equivalent depth of pressure (due to the air pressure drop inside the light) would be about 1 meter, which is the IPx7 rating.
So, I dunno. Personally, I don’t think it should have leaked. But, it’s getting close to the limit. So, I wouldn’t blame the light. It’s a good thing to know, though.
So how many inches under water in a glass = 1 meter ?
I think some guys would be very happy with this math 
Took me a few seconds to understand the humor but I got it.
But this thread made me aware that if you accidentally drop a "hot" IPX7 rated light into a shallow puddle of water, it could suck in some water if you do not take it out quickly before it cools down.
Thanks for the deep analysis gentlemen. For added datum point, the light was submerged in roughly 8cm of water. Went in warm, came out warm after heating up the cold tap water. So there was certainly a cool down and warm up cycle submerged. I would estimate that 10cc of water ingressed (Shocked at the amount). First power up was basically uncontrollable. Modes and levels were changing without touching the button. Now it is basically controllable, but it is difficult to change any settings due to unpredictable button behavior. The button is still touch sensitive after many days in the rice bag fully opened up. Thinking it is time to reorder, and chalk this one up as spare parts. Worst case at least the battery tube doubles as a charger and cell holder…
Edit: Reorder placed, $124 lesson learned.
NOCTIGON K9.3 DUAL CHANNEL 7400LM 21700 LED FLASHLIGHT
Color
Dark Grey
Switch back light color
Amber
CH1 (9 inner LEDs)
Warm White - SST20 2700K 95CRI
CH2 (3 outer LEDs)
SST-20 Deep Red, 660nm
Anytime I’ve dunked my cell phones (before I could afford properly-rated ones) I immediately remove the batteries, drain the capacitors, and put it in some kind of desiccant (dry brown rice or moisture absorbent packs) and leave it for a few days before firing it back up. It usually works, but the last one killed my Note 4 after a kayaking incident so I got a IP68 Note 8. It’s gone swimming more than once and no issues.
For flashlights, they are only as good as the person assembling them. Grease and o-rings can be omitted, the wrong o-ring can get in by accident, or it can get damaged during assembly. Maybe a poorly machined part that doesn’t mate properly? Generally, reputed manufacturers are trustworthy with this, test, and rate their lights properly, while some…not so much. Like with lumens or throw, it’s easy to stick a IP rating on a box when it hasn’t been properly tested or rated.
While I’m not an expert on Ingress Protection ratings, IP67 would only be a water resistance test where jets of water or a certain size would be focused on the light and it would have to survive that for a set period of time like 1/2hr. Water and dust ‘resistance’ is way different to the IPX-8 type ‘waterproof’ rating where the test involves submersion into 1m+ of water for a certain amount of hours…I think it’s 8 hours or something. Then after being certified the manufacturer states the exact depth say up to 2meters. I would NEVER submerge an IP-67 product into water, it’s asking for trouble, would I take it out and use it in the rain, absolutely…that’s what its rated to do.
You’re wrong. Wiki
Test for IPX7:
Test duration: 30 minutes.
Tested with the lowest point of the enclosure 1,000 mm (39 in) below the surface of the water, or the highest point 150 mm (5.9 in) below the surface, whichever is deeper.
Exactly, and IPX8 has a kind of floating set of specifications.
Where the manufacturer puts in his/her own variables.
Wheneven you read IPX8, it should always be followed by: X duration and Y depth.
You my friend need to put a mild solvent in there to try and clean some of the dissolved ions off of the switch. You will need to take the switch cover off. Try Isopropyl Alcohol, must be really pure like 99%, it works great.
Just want to mention I dropped my green D4S in a sewage pipe one time, and had to fish it out. It was an interesting experience…
Mark, I have some 99.9% iso, switch cover is removed. You are suggesting a flush over the switch area then back to the rice bag?
Yes flush multiple times and let it air dry for 3-5 minutes, no need to put back into the rice bag. No battery inside please.
just fyi, rice is pretty much a troll. it's not a good desiccant. no point in using it.
even if it were good (again, it's not), its ability to remove moisture is related to its moisture content. many rice bags aren't airtight (they're damaged or even have little holes intentionally punched in them for air exchange) and have basically reached their equilibrium moisture content with the environment. this means it's no better than just letting it air dry.
if you have an electronic device that's suffered liquid ingress, the best strategy is:
Thank you! I’ve been holding back saying the same thing, because every time I do the “anecdotal evidence” pours in.
Also, besides being less effective than simple air-drying, you also risk getting all kinds of organic dust all over the inside of your light.
Rice is a really bad idea. For whatever reason, it’s become an urban legend.
Yes, hair dryer on low temp. Good and pretty long.
Remember warm air can contain more moisture than cold air.
So if you use warm air for a short period, you can think that all the moisture is out.
But when your light cools down, the moisture IN the air can condensate in/on your light!
Hello all,
Tujone was kind enough to send me his faulty K9.3 for debugging to see if I can figure out what's going on. I agreed to update this thread on what I found.
Immediately after receiving it, I quickly found out what Tujone meant with the problem - the button control is the main issue, and it is both sensitive at times and sometimes doesn't register at all, quite unpredictable. For example, I managed to trigger a press just by placing it down on my table once, but it's inconsistent. I can see why it was causing trouble; control of the flashlight is tricky especially since Anduril is a button-heavy UI.
At the moment I've been slammed with a bunch of work so it may take me a little time to get to the bench to do a proper investigation and disassembly, but my initial guess is some sort of contamination / water exists on the switch or PCB. I'll see if I can get to the root cause of it and post updates here.
Some of you know that I was asked by Fireflies to help with a driver for their E12R so I have an early prototype to compare it with the K9.3 because they look similar. I won't comment much on the E12R since I don't have a production light and I'm not impartial, because I helped work on it. However, I was impressed with the finish and construction of the K9.3, and surprised to find that there was water ingress in just a glass. On paper, it is slightly larger and heavier than the E12R,but the difference in feeling is obvious. They seem to be different flashlights in terms of output and purpose, though, so it may not be an apples-to-apples comparison.
More to come soon.
Every light I own gets the water test, one did fail same way as OP i put it in warm and let it heat water up(FW3A)
Took it out water in the tube, dried it out etc and it all worked again fine.
As for longevity or any corrosion who knows as that light will most likely have been replaced.
Had some time this weekend, so I took apart the Noctigon K9.3 which I got from Tujone to see what was the main cause of the button /water issue.
In summary - it appears that water must have got into the dome switch of the K9.3. The switch is a standard SMT low-profile dome switch with a plastic surround, and it appeared to be potted with some sort of water-proofing compound around the edges. I was able to (mostly) fix the problem by baking the switch for half an hour in a reflow oven. It's much better now, but still a little finicky sometimes, so likely the switch had some contamination from the water + dissolved things. The driver and LEDs were fine.
With the K9.3 in hand, I thought I'd do some comparisons with existing flashlights that I currently have. Specifically, I wanted to compare it with the Fireflies E12R, as they appear to be similar and lots of people appear to have questions.
From left to right, Fireflies E07, Noctigon K9.3, Fireflies E12R (prototype), Noctigon KR-1, Lumintop FW3A. The left three are 21700 flashlights. Note - my E12R is a prototype and I put a piece of tape on the switch because I haven't pressed the switch ring in yet (and it is loose). If you didn't know, I was asked by Fireflies to design the driver for the E12R to their specifications, so I will refrain on commenting on its performance as I'm not impartial. However, I'd like to talk a bit about the machining and design, which I had no input on.
On paper, the K9.3 is only slightly bigger and heavier than the E12R, but it actually feels substantially larger in the hand, and is definitely on the heavier/bigger side for an EDC, even for a big jacket pocket. In the hand, the E12R feels really nicely balanced and the 'trombone' shape actually helps it fit in the hand well. In comparison, the K9.3 feels very front heavy (there's a LOT of metal in the head, as I will describe soon), and the center of balance is somewhere near the E-switch! However, the heft does make it feel like a premium product, though perhaps it can be a little heavy for EDC.
In terms of finish, both the Noctigon and Fireflies have similar quality of anodizing - they both feel smooth, even, and robust. However, I have to say that I generally prefer the colour of anodizing that Noctigon chooses - the dark grey looks a fair bit more premium than the black of the Fireflies. The scalloped stainless-steel bezel of the K9.3 is also very nice. Finally, I also prefer the texturing of the grip on the K9.3. I suppose this is just personal preference, though.
To summarize:
For a flashlight of this formfactor, I'd like the shape and size of the E12R combined with the machining finish and anodization of the K9.3.
It's time to disassemble. The K9.3 I received from Thujone was misbehaving and the switch was extremely sensitive and inconsistent.
First was to remove the optics. This comes apart very easily. You can see that the K9.3 actually uses three triple optics plus three single optics. They are positioned and held in place with a nice frosted plastic spacer. This is topped by a large 49.5mm diameter 2.5mm thick AR-coated glass lens, held in placed by the scalloped stainless-steel bezel ring, and two red O-rings. It's nice to see a quality-looking glass, but it definitely contributes significantly to the front-heaviness of the flashlight. I'd like to see perhaps a thinner 1mm ion-treated lens instead, like gorilla glass (what Zebralight uses for the SC700d).
Out comes the optics and you can see the white aux-led PCB with 15 RGB LEDs, along with (in this case) nine 2700K SST20 emitters and nine red emitters. A total of 8 wires are needed for this - four for the two main LED channels and 4 for the aux LEDs.
I had to disassemble the flashlight to get to the switch PCB and to remove it. As I had expected, the driver tested out fine, but the switch PCB was the issue. I found that with the slightest pressure on the switch, the switch resistance didn't drop to zero but hovered inconsistently around the few hundred ohms range. This indicated to me that most likely there was some contamination inside the switch itself, i.e. water got in and stayed there.
Here's the switch PCB removed, with the dome switch. You may be able to make out some conformal coating around the switch - it looks like it was there to prevent water from getting into the switch, but unfortunately, water seemed to get in, and the coating made it stay there. I tried blowing hot air on the switch for a while but it didn't solve the problem. Ideally I would replace the switch, but I can't get parts quickly, so I decided to throw it in the reflow oven and I baked it at 150C for about half an hour, placing it sideways.
While doing this, I had some time to take a look at the driver. It's a pretty simple design- two Constant Current Linear Channels, each up to 8.95A, one of which has a turbo FET direct drive (for the 9 LEDs).
The main MCU is the standard ATtiny1634. There is aux RGB LED support, as well as a external LED for the switch. Power is provided via a 2.8V regulator. Sense resistors are 1206 10mR resistors, and the feedback loop for each CC stage is handled via a TLV333 op-amp, using a Mosfet as a linear pass element. The driver is 29.9mm OD with a 2.6mm ground ring around both top and bottom, with a 11mm spring pad for the battery-side. PCB measures 1.6mm thick.
I drew a rough schematic of it, pretty standard implementation. Control is done via the standard OC1A/B 10bit PWM at 3.9kHz. It's filtered through a RC LPF and acts as the reference voltage for each linear constant current stage using a Mosfet as a pass element. Simple and effective, but fairly inefficient as well. It's one step up from the AMC7135 regulators since brightness control is now PWM-free, but the downside is that it still regulates and burns excess energy as pure heat (i.e. the pass element acts as a resistor).
One thing about the K9.3 design is that there is a huge driver cavity, which makes sense since there needs to be a lot of wires (as you can see above), and it would be difficult to assemble if the cavity was shallower. The driver cavity measures 25.4mm in diameter and 10mm deep - this makes for excellent modding potential, with the drawback being that the MCPCB is custom, so it's difficult to use different emitters of different sizes. In addition, I found that the LED shelf is a whopping 8mm thick!! No wonder the front of this flashlight is so heavy! There is a lot of metal here.
For those keeping track, the main LED MCPCB is 45mm in diameter.
With the switch out of the oven, I found that it was finally working decently again. Not perfect, but it's possible that the water submersion dissolved contaminants around and in the switch; while most of the water should be baked off, the contacts are likely slightly contaminated still, and the switch is no longer perfect. But it's much better than before. So I assembled everything back together. The most difficult was getting all those wires through the holes. It took a bit of patience, and help with needle tweezers to get this done.
Problem mostly solved for now (I'm going to ask Hank what switch he used or if he can ship over a new switch PCB, since the switch is still slightly finicky), or if I have time I can dig around digikey to find a better replacement).
So.. what about the charger? The charger is integrated in the body-part of the flashlight, on the top of the battery. Again, this adds some additional weight and mass to the top of the flashlight, making it very front-heavy. However, this also makes the flashlight theoretically more waterproof than the E12R, which just uses a rubber flap.
The charging electronics are covered by a press-fit white plastic spacer, which I removed easily. The charger circuit is essentially a datasheet-recommended implementation of the TP5000 2A charger IC. https://www.rzxpoweric.com/data/upload/image/20190515/1557926480137873.pdf The CC USB C lines are terminated with 5.1k, so this should work with most USB C - USB C chargers.
Finally, one thing I noticed... this flashlight has no reverse polarity protection. I didn't see any on the main driver PCB... and I only tested this after I had re-assembled the flashlight, so I haven't been able to do a detailed analysis. It appears that there is some reverse current flow (my guess is that it's through the LDO, which also may cause reverse current through other ICs). The LDO has a marking LB28 L7F1, so while I initially guessed it is the MIC5025, the markings don't quite match, and the MIC5025 does have RCB (it is a footprint compatible part though). So just a note, do not insert the battery backwards in the K9.3, or there may be magic smoke coming out!
I tested this quickly with a bench supply with CC mode, and sure enough it seemed almost a short when plugged in backwards (there is a V_fwd drop which looks like some diode forward voltage). I thought that perhaps there would be some RPP in the charger PCB but it looks like there isn't, though the charger IC itself has RCP internally so it shouldn't be affected. Note that I haven't looked at this in detail so perhaps I missed something, and I only tested this at a low 2V.
As for why would water get in - the entire flashlight seems fairly well designed. Two large o-rings prevent water ingress from the front - adding silicone grease should help in general water tightness. The main body threads also have an o-ring each, and appear to be decent quality. The switch is held in place via a rubber dome, squeezed in via a switch ring - that needs to be screwed in tight for water-tightness, so perhaps Tujone's one had a leak somewhere around the switch dome, and water got in?
Overall - my thoughts on the K9.3 are a little mixed. I am impressed as usual, with the workmanship and machining, as well as the large amount of engineering that clearly went into the entire design, from the charger in the body tube, to the complicated MCPCB / Aux PCB / Optic combo.
However, I felt that this created a somewhat... inelegant design, and the overall package was a little.. big. The flashlight is a little too front-heavy, affecting ergonomics. The 9+3 LED design looks interesting but the choice of optics leads to an unnecessarily large head (the E12R also has 12 LEDs but is a fair bit smaller). The head is well machined, but it has a driver that I think could be improved to take advantage of all the space. This flashlight also has a comparatively large number of components both mechanical, optical, and electrical, leading to a complicated and time-consuming assembly (including the soldering). For a 21700 flashlight, is also very big compared to say a Fireflies E07, Lumintop FW21, or even a Zebralight SC700d (much much smaller!).
Thanks for reading!
True but i took my old Xperia Z under salt water and it survived fine.
best review of the light out there. and it's an incidental review, lol.
Well, that’s nothing new. The first D4 had no RPP either, and if a battery was put in backwards (easy to do with flat tops), would heat the battery to dangerous levels. I tested it once and the outside of the flashlight rose to almost 200ºF (93C). The battery inside must have been ready to go nuclear