The big issue with using the NiMH AA cells as 2S, is their nominal voltage is two low, ad below the forward voltage of the LEDs. (for NiMH you need to use 3-series with a 47 ohm 1/4 watt resistor to get the correct output. 2AA Alkaline cells have a higher voltage and can run a LED without a driver, (i use a simple 7.5 ohm resistor in series with the LED for running 2 alkaline or ZincCarbon cells.
Is anyone in the US who has received theirs able to post how long they took to arrive?
Mine have been listed as sitting at “SUVARNABHUMI MAIL CENTRE” for almost 3 weeks now.
Now that you mentioned it, there are some people who has already received the package despite it’s being shipped later.
It’s probably time for me to start a formal investigation with the post office.
One thing to note is that Thailand Post usually send the mail to two different U.S. airports; one in New York and another in Los Angeles. As of now, the mail that moves fast are the ones that appears in NY.
There’s a possibility that the LAX is jammed with packages those packages are the ones waiting to be scanned as “Processed Through Facility”.
Nonetheless, I will start launching an investigation.
Mine was shipped Dec 12 and I still haven’t received it in NY. My last shipment took about 2 weeks as I remember. I’m not too worried about it, as I also think the volume of shipping this time of year may be delaying things a little.
Edit:Just went to the mailbox and they are here! Thanks rngwn!
Still haven’t got them here…
If I’m dealing with lost shipments for that whole 1 Dec batch then it’s going to cost me dearly 
I think they will arrive eventually.
It’s the end of the year, millions of packages are shipped, normally takes 1 to 2 months, we’re at 23 days since i paid you.
I did receive the 4000K 16-die led last week, which was really quick, so not all packages are on hold, some slip through.
Same from dec 12 order date. Hopefully it’s just some USPS congestion during the holidays.
Thank you for looking into this. LAX is definitely a possibility - I’ve had shipments held up there before. It also seems quite possible Thai post is overwhelmed, as well.
Fortunately, I’ve got time to wait and see if my tracking number starts to see movement. I was going to put make small gifts to nephews with some of these, but fortunately, I’ve still got some Yuji’s to spare.
It turns out 3 x alkaline button cells produces a lot more current than lithium coin cells.
I found a cheap 5-pack of “Buck Lights” on Amazon that seemed like a good choice for kids because they are momentary only (can’t be accidentally left on), and the cases screw together, so it should be extremely unlikely they’d be able to open the light and risk swallowing the batteries.
I was surprised how bright they are, so I put a multimeter on them and measured 90mA. This is pretty hard overdriven, but in short bursts, they should not overheat, and the voltage sag dropped that by about 10mA in the first 10 seconds alone, which will likely help prevent harm to the emitter.
A new CR2032 with a Yuji produced only 14 mA (which I find a really good level for finding things in my car).
rngwn’s emitters should be even brighter on alkaline button cells than the Yuji’s, including those Mateminco bullet lights
I think the lights I have use LR41 cells, but I didn’t check the dimensions when I had them open.
Tip:
http://kaidomain.com/S028538-UV1-365nm-1-Mode-Stainless-Steel-UV-Flashlight-1xAAA?page=2
I did not make pictures of the mod but this is a pretty nice host for 5mm leds. A small description: the bezel is press-fit, work it out by prying with a sharp knife between bezel and body. Inside you will find a great little convex-convex lens and under it a plastic holder that retains a small circuit board and a 5mm (UV) led.
Replacing that led with your favourite 5mm led is not just a matter of unsoldering/soldering because the stock UV-led has a very narrow emission angle and probably your replacement led needs to sit closer to the lens to prevent light loss and obtain a good beam. But the plastic holder has a rim on the inside that holds the led at a fixed distance from the lens. So that rim needs to be reamed until your led can be slided through the hole towards the lens. Then, outside the flashlight, light your bare replacement led with a led tester and hold the loose lens in front of it at a distance that gives an optimal nice beam, precisely measure that distance. Then bend and solder the led onto the circuit board sticking out so far out of the board that your measured distance is met upon assembling the lens/plasticholder/circuitboard combination.
Pictures tell a thousand words but unfortunately I don’t have any. But it is easy to see what needs happening when you have the flashlight before you. It is an easy mod.
I used a rngwn 2300K led and chose a beam with the die projected by the lens just out of focus, so it is quite throwy compared to the bare 5mm led. It has a tint shift from 2700K in the center to 2100K near the edge (so getting pretty orange there) but because of the great tint and CRI that actually looks rather attractive. The current from the battery is 122mA (so about 40mA through the led after boosting) and the output is 10.5 lumen, which sounds worse than it is because the light is more concentrated than any bare 5mm led.
My post office has taken my case and should start an investigation on the delayed shipment for iamlucky13 soon.
They might mail you an inquiry card asking if you would get the item by the time the card arrives.
My emitters showed up just just before Christmas!
Something is probably up in USPS LA now. Even my packages that lands on NY doesn’t even want to go to LA right now. 
Thank you again for following up on this.
I received the inquiry from the USPS and mailed it back this morning to confirm that I have not received the shipment. It seems a bit odd that this would even be needed, since Thai Post’s own tracking information still shows the package as at Suvarnabhumi Mail Centre, so it’s not like they had any reason to think it had been delivered.
Hopefully this results in either Thai Post locating the package or reimbursing you fully. I will check in again in a couple weeks if nothing seems to have happened.
Bureaucracy at its finest.
I think THP is trying to ask the receiver first before checking their backlog.
EDIT: In the worst case, I will just need to reship all the packages that was sent on Dec 1, if it keep going onto the mid-January without any progress.
Probably without tracking though, since I will be eating the shipping costs for the reshipping. If that happens and you do receive two shipments, then you can consider reimbursing me later.
Since the mails are sent without insurance (which I have calculated the risk v. indemnity of this before), if the mails are really lost then I’m screwed. I hope they would at least try to find the mails before screwing me over.
(I still haven’t received them yet either… 
)
Bummer…
Contact me if you have to re-ship.
I may want to order some more.
I’m waiting on a bucket-load of packages atm, the ones that have tracking are said to have left China. Maybe postnl has a huge pile somewhere that they stopped working on until after the Christmas peak.
Me too.
It wasn’t too smart to order a bunch of stuff in December…