Thanks Chloe for paying attention to what’s going on and all the updates 
Just saw the first comment, 
Hope the new staff training goes well.
Thank you so much Chloe, for keeping us informed!
I noticed that the USPS office here has a notice saying that bare li-ion cells can't be shipped internationally, but cells installed in devices CAN be shipped. (stupid? yes....) So this sounds like a workaround. Take the bare cells, place them in a sealed tube so that any 'venting' will be accompanied via a significant explosion, with shrapnel...
So, what's the cheapest 2x 18650 host on Fasttech?
Here's the 501d for $16.04:
How about a box? These can be closed with cells installed and are inexpensive...
2x18650 - $2.84 https://www.fasttech.com/products/0/10003498/1258801-218650-battery-holder-case-box
4x18650 - $4.07 https://www.fasttech.com/products/0/10003990/1286603-diy-234-x-18650-batteries-holder-case-box-mobile-p
Love that! First it was Meth Labs, now it will be Li-ion Labs. No more buying Li-ions, or we will be put under police watch and Homeland Security will come to our doors with automatic weapons! Mandatory 20 year sentence for having more than six Li-ions in your home! Possession with intent to distribute...
I'm gonna go back to doing NiMH lights.
Cells doesn’t spontaneously vent. A flastlight would prevent from outside damage (of course it must be protected from short circuit or activation).
...um... That was supposed to be sarcastic humor. If spontaneous venting isn't what we are scared of, then what's the problem? 
I’d guess selling cells installed in flashllights is to prevent detectio
n and not for the sake of safety…
Somewhere in one of these shipping threads is a post office quote stating that the batteries enclosed in a device (flashlight or otherwise) is fine, but by themselves is not allowed.
I’ve got a ticket in, asking if this http://www.fasttech.com/products/1420/10003913/1280800-4x18650-emergency-mobile-power-rechargeable + 4-18650s might make it through.
This is no problem, so just order
Do we have to somehow tell them to install the batteries into the light, or will they do that automatically?
did you read or just stu*?
Well I read “can” implied to me that it’s an option. It could just be language barrier though and they meant “will” though that could be misconstrued as well… Perhaps I’m reading into it too much.
Me thinks koyotee is just being a d*.
I read through the typically vague USPS regulations this morning. It appears that as long as the batteries are installed in a device which is protected from turning on/short circuiting in transit, then you are within the rules.
FT would be technically be in compliance by inserting the batteries into devices with insulation disks, like they are proposing doing.
The problem is, as with so many of these agencies, that they subjectively choose when and how to enforce the regulations with little to no oversight.
This is the problem, RMM. ;_; I am hoping there will be clearer rules set forth regarding safe packaging, training staff on handling procedures, instead of blanket banning.
I just placed an order for the above mentioned ” 4x18650 Emergency Mobile Power Rechargeable Batteries Pack Charging Box “:https://www.fasttech.com/products/1280801 + 4- LG D1 18650s and told them to put the batteries in the box. We’ll see what happens….the things I do for BLF….oy. 
I’m looking at it like - 4xD1’s for $24.15….and it comes with a free charger!!
Here’s what the aviation industry is concerned about, for reference:
As you can see they’d been working hard (well, until the government funding lapsed) to get a clear description of safe ways to package large boxes full of Li-ion cells.
Unfortunately for all concerned, most of the fires on aircraft didn’t leave much evidence behind, so what’s here are experiments trying to assess the problem.
One of those pictured sloppily packaged boxes — half full of loose cells knocking around with the cardboard dividers falling apart — would be pretty scary.
No, it’s not you or me they’re after, but in the cargo hold at 33,000 feet, all of the packages look the same.
They don’t spontaneously vent. But they also dont necessarily vent when directly targeted and damaged by large crushing forces. It seems more likely that a cell is over discharged and vents than has deliberate damage done to it.
So my observation has been; isn’t the probability that someone will load a device which can accidentally be turned on/overdischarged and vent (or cause a fire by a massively hot multi-LED light in an enclosed space with paper) much more likely than someone gets a sledge hammer or ice pick and randomly smashes mail hitting the batteries or runs over the package with a Hummer?