[Teardown] SEEKNITE S11 GITD

Unfortunately, I have already reassembled the flashlight.
I wouldn’t mind taking it apart again, but in order to desolder the battery you have to remove it by undoing the new glue, which I really don’t feel like doing. Sorry.

I’ll tell you what though, eventually I will find a seller on AliExpress that will actually ship those flashlights to me, and when it arrives I will also measure the quiescent current (heck, maybe I’ll even measure the PWM frequency), and if we find that the other one is completely identical to this S11 (other than the GITD shell, of course), then I think it’s a good bet to assume that they have the same (or very similar ) quiescent current too.

Thanks for the teardown, this seems like a mixed version of Rovyvon A5 and newer A5X series, with the upgraded battery capacity but old PCB design. I paid a little bit more for mine on aliexpress boruit store.

I have now received my S11, and I observe the opposite. The TIKI GITD main LED seems to be warmer for me, maybe 5500K. The S11 looks like 6000K or 6500K.
Edit: Actually, my light has a completely different main LED than the one you received. The packaging says Samsung LH351B, but I’m not familiar with this type and can’t visually confirm this. The white markings on the PCB that holds the main LED are also slightly different.

Again, I observe the opposite. The Nitecore TIKI’s UV light is surprisingly strong for such a tiny thing, and the S11’s UV is even noticeably stronger.
I think the unclean UV could be because the UV output goes through the GITD shell and because some UV is reflected onto the phosphor layers of the neighboring white and red LEDs.

I have had this only for a day, but so far I quite like it. The cool white LEDs are a bummer.
With NW, high CRI side and front LEDs (side is more important, and probably harder to mod) this light would be extremely good.

I measured battery voltage after the built-in charger terminated at 4.17 V, that seems a good, healthy value.
Terminating the CV phase a bit early also helps to achieve the incredibly short charging time.

Is the footprint oft the side LEDs known? Maybe blue could be replaced with amber to make the police strobe more like traffic strobe.

master-of-disaster, I received my S11 from AliExpress today and I can confirm your observations about the main LED: It is indeed LH351B, and it is cold white, 6000k-6500k looks spot on.

I like cold white better than natural and warm, but if you like the warmer ones, why didn’t you buy the GITD version from Banggood? (it’s still $12.99, I believe)

It’ll take me a while to finish the tests, maybe a day or two, but in the meanwhile I can tell you that the quiescent current is about 1.0uA with a full battery. I also measured all the current consumptions. I will add everything to the OP once I’m done.

Is there any way to tell without desoldering them?

Yes, by knowing them from looking at them :smiley: .

More seriously, I wonder why no one thus far tried this mod. That thing is or was cheap enough to buy it out of curiosity.

I didn’t know there were Versions with different LEDs. The aliexpress seller I bought from shows the exact same specs as banggood (SST-20 LED).

Regarding battery health I’m getting concerned about just how hot this thing may run - with the light disassembled and UV on, the main PCB gets painfully hot within ten seconds or so.
I will attempt some battery temperature measurements in the assembled state tomorrow if I can shove a thermocouple through the charge port.

Oh yeah, mine actually shows SST20 too. Huh, I didn’t even notice.

You can probably get a refund, or at least a partial one if you care to go to all the trouble of a dispute. If you do, take a photo of the S11 box with the package (envelope) next to it and in the description you can link to this image:
Imgur
and tell them that this is what you should’ve received.

I ordered mind from Fasttech and it have parasitic drain. The battery last about a week with full charge.

I contacted Fasttech and they ask for video proof but i find it hard to video.

Do others have same issue?

I have updated the original post with the new flashlight tests.

As I mentioned earlier, mine has a 1uA parasitic drain, so no, I don’t have the same problem.
I can’t think of any good proof other than a time lapse with a clock next to the flashlight, but that is a lot of work.

If you want to try to fix it, maybe you should try to desolder one battery wire and after a few minutes reconnect it. Might reset the MCU and help. Also, while you’re in there, maybe put some Kapton tape on the wires’ solder points on the board, because maybe the metallic battery case is shorting them.

Thermal measurements
Because this type of flashlight does not have an easily replaceable battery, and temperature is the most important factor for battery health (excepting misuse), I measured battery temperatures during operation.

The light is an S11 from aliexpress that seems to be the same as the one Flail has added to his original post update. I added a bit of thermal paste between the brass heatsink and the PCB that holds the main LED, because there was only a tiny amount (see Flail’s pictures).

The thermocouple was placed inside the plastic shell of the fully assembled light, next to the middle of the battery and lightly touching it. The actual battery temperature next to the thermocouple could have been higher due to poor thermal contact. The battery temperature will not be uniform, so this measurement likely does not represent the hottest part of the battery (which is the part that matters). It also does not represent the hottest part of the light (not at all) which will be at different locations depending on the mode you are running.
The battery seems to be glued to the PCB with some type of foam, this is good and should help protect the battery from the hot PCB.

Front LED, medium setting (highest continuous setting without stepdown), 90% battery charge
The measurement was stopped after 25 minutes because the temperature didn’t increase any further.
Highest measured temperature was 7 °C above ambient. This is absolutely fine.

Front LED, momentary high (highest possible output), 100% battery charge
The measurement was stopped after 200 s. Temperature was still increasing at this point, but not very quickly. I doubt anybody would use momentary for much longer.
Highest measured temperature was 20°C above ambient. This is high, but acceptable and to be expected with such a high performance in a tiny package.
The stainless steel bezel was painfully hot after this run, presumably much hotter than the battery. This indicates that the heatsinking through the brass piece to the bezel works.

White side LED (“lantern mode”), 100% battery charge
The measurement was stopped after 30 minutes because the temperature didn’t increase any further.
Highest measured temperature was 11 °C above ambient. This is fine.

Red side LED, 70% battery charge
The measurement was stopped after 25 minutes because the temperature started decreasing (battery voltage dropping).
Highest measured temperature was 16 °C above ambient. This is higher than the white side LED and would have been even higher with a full battery. If you are worried about battery health, don’t run this mode continuously on a full battery, especially in a hot environment.

UV side LED, 100% battery charge
The measurement was stopped after 8 minutes because I didn’t want to cook my battery. Temperature was still rising at this point.
Highest measured temperature was 28 °C above ambient. If I had not turned the light off, Temperature at the measurement location would probably have reached 33 °C above ambient and stayed there. This is not ok and could be dangerous. Don’t run this mode continuously, even if you think it’s a nice party trick. It will ruin your battery, unless you place the light in a very cold environment. Running the UV for 2 minutes is ok.
If a manufacturer puts in a side LED with this much power, there must be a time-controlled stepdown or a temperature regulation.

Charging from ~ 50% state of charge
Flail’s measurements show that charging in this light is unhealthily fast, so I measured battery temperature during charging. Charging from empty would have been a more useful measurement (probably with a bit higher temperature), but I didn’t have enough time for that.
Highest battery temperature during charging from 50% was 13 °C above ambient. This is ok.

Thanks very much for these terrific tests and analysis. I see $8.39-$10.97 with 50 piece MOQ at that Alibaba link now. At 10 pieces a group buy might have made some sense. Oh well. Current BangGood price is $20.99 and it looks like Fin17’s coupon is still active (edited), so I’m tempted.

There is sure a lot of stuff on the board! I don’t really see the usefulness of all those different side leds. I think I’d change them all to warm white. It would be interesting to identify the MCU: it could conceivably be reprogrammed.

I’ve been a bit intrigued by the RovyVon A5X but didn’t want to pay $30+ for a disposable light. At $12.99 this similar Seeknite is more attractive, especially if I can locate replacement batteries.

I like the low weight and small size of the light, don’t care for the complexity of the side leds, don’t care for the scorching max output of the main led, but can live with those things. At least this light really gets some size and weight reduction from the internal lipo and plastic shell, compared to traditional metal cylindrical lights.

About a month back, I found a seller on Alibaba that had a price of about $7 per piece with a minimum order of 10. I actually thought about trying Alibaba for the 1st time, but eventually I decided it wasn’t worth the hassle. Not when the price on AliExpress is $10.97:
https://www.aliexpress.com/item/1005002393158222.html
(for the non-GITD cold white version)

As for the MCU, IMHO, the chance of it being reprogrammable is 0.0000001%. There is simply no reason whatsoever to use an MCU with a flash memory when OTP MCUs are at least an order of magnitude cheaper! For example, take the PADAUK PMS152 - a 14 pin MCU with 7 outputs which were specifically designed to drive LEDs and LED flashlights. It costs only 5 cents a piece:

As for the battery, I couldn’t find the exact same battery for sale, but you could probably put a slightly smaller battery without a problem.

Sigh yeah, that is a good point about the MCU possibly being something like a Padauk. If it can be identified, then in principle it could be replaced with a newly programmed one, but it would be way more trouble than it is worth. The thing intriguing me about this light is its very low weight compared to a 10440 or 10330 light of roughly the same specs. I think that is mostly due to the polycarbonate shell weighing less than a metal tube. Perhaps it’s time for some 3d printed flashlights for this purpose.

It’s amusing that the battery has “260 mah” printed right on it, yet the aliexpress pages all claim 400mah. Even at 260mah though, the energy density is quite good compared to a cylindrical cell.

Nice find with the generic non-gitd model. I think if I get one though, I’d use the $12.99 coupon for a Seeknite branded gitd one.

You’ve probably seen this Padauk article by Jay Carlson, but just in case:

As per my measurements, there's no PWM on moonlight, low and turbo. High and medium is 20khz PWM. Side LEDs (white and red) are 200hz PWM.

Seems like they're using a different LED now. On the left is supposedly an SST20 and on the right is the real one.

Hi, please help me, memory for sidelights don’t work, I mean instructions say “3 minutes” memory for sidelights on continue light after turn off … but it doesn’t work :cry: .

I just got mine and it also came with this unknown LED. Also has some other differences compared to the 2021 units like revised pcb and no thermal paste on the copper sink.
The box still claims SST20.