I also have the DT70 and DT35 (love ’em both!). Big plus is that the batteries are parallel, protected, and you can monitor each battery as well.
Good to know
It sounds like maybe the batteries did not vent (I would actually be surprised with 30Q’s) but the driver seriously got on fire. But if so, I’m sure the pictures will reveal that.
Oh yeah, that’s for sure the driver.
I still remember when I killed my Haikelite MT01 driver.
Quite a bit of smoke from the inductor and the like.
Didn’t kill the LED at least.
Quality 18650s like the Samsung 30Q will not explode or vent without something physically triggering it, as the internal PTC would shut it off very quickly.
That means there was a driver short, as unused cells will not do anything if you just turn it on.
How the symptoms occurred reminds me of a driver short.
TLDR: Probably a driver short from a lack of QC during wire soldering.
Very glad to hear that you were able to contain a potential disaster! That could’ve ended up very, very badly especially if the flashlight developed enough pressure to break the threads and actually force the bottom battery cap off of the light. I too have a DX80 and the bottom battery cap is at least 8 threads deep. The pressure required to bust that open could’ve easily put the cells in a possible failure scenario and made this a catastrophe.
Glad you’re alright and hope that your house doesn’t stink too badly! Burning electronic smoke/stench is awful
PS- I’m 99% certain the DX80 is an 8x 18650 configuration not 6x 18650
UPDATE: it appears to be a driver fire, (and in a sealed light it pressurized the head)
The battery pack still shows 16 volts. but attempting to get the retaining ring to remove the driver its seems to be fused to the back of the driver and tries to turn the entire part. Have anyone had a DX80 take apart before?
Below are photos of the smoke-filled lens and smoke residue on the battery cap:
Glad to hear it wasn’t the battery.
Sounds like rather than trying to disassemble the light further you should contact Imalent. M4D M4X says they are very interested in investigating the cause. Hopefully they will also repair or replace your light as well as ensuring that this doesn’t happen again in other lights.
On the upside, we have now identified another advantage of USB charging in flashlights: The USB cover serves as an emergency vent. 
Can you post a photo of the threads on the battery cap & battery tube?
Thanks for the pictures, that looks rather frightening. Imagine this happened in a car while driving or similar.
The threads are ok, but dirty now from the smoke gassing past them, it blew the upper o ring out though.
ok thanks, i sent them an inquiry on my incident.
more photos:
showing the melted copper traces & burned driver board, ( the area under the plastic cap) I can not get the driver or head apart, even with a strap wrench, and will wait until i hear back from Imalent…
The upper o-ring had failed, and hot smoke blew past the threads.
resulting smoke burn to my fingers.
wow, that looks bad. I am so glad you are OK
Terrifying. So this was just a QC fail?
Glad it was not more serious.
I have heard so many bad things about this manufacturer[add another],It is a wonder people still buy these lights. 
I have no idea… the head of this light is glued very solid, so i can;t get it apart to see what failed, but either way the driver is burnt to a crisp, and parts now are lose inside and rattle around. it made a hiss with some crackling & a popping noise before i managed to get the battery tube off it to stop the smoke from spraying out of it.
Imalent might try some funny business if you keep trying to disassemble the light.
See this thread:
https://budgetlightforum.com/t/-/54892
VOB did a full tear down and the only way to access the driver was to completely destroy the head of the light
Imalent may try to claim foul play if you start ripping pieces apart that they’ve purposefully designed to never come apart
I only tried to loosen the driver ring once, then stopped as i know its best to leaf it as is until they get back to me.
I wonder what would be the best way to present your case to them? If you present yourself as an average ignorant consumer they could try to take advantage of your “ignorance” and give you the runaround. On the other hand, if you make it clear you are a flashlight expert that is active on a large forum, they might think you were monkeying around with something on the light.
Didn’t know drivers can catch fire. I hope they figure out what caused it. With the MS18 with 8×21700 high drain cells, it would be even more dangerous. I’m planning to buy the MS18 and R90TS too.