If the drain is very low, like what happens with a lighted tail flashlight, or one with high parasitic drain (FT02!!!), the protection circuit may not be triggered and the drain continues beyond the safe voltage.
Or am I mistaken with what some flashlight drivers do and will protected cells indeed detect the correct voltage and shut off even with very low drain?
Thank you, djozz and Lightbringer for your advice regarding DTP and non-DTP MCPCBs. Nice and useful test you did there, djozz. 
I think I managed to get very unlucky. It is an EVVA 10A protected cell but it was stuck in the mail for a week and it wouldn’t charge for a few days after it got here. My charger read resistance to be 999mΩ, so I think I’ll see what I can do when It comes to sending it back.
Thanks hank,JasonWW and djozz.
Is this a random question?
The low voltage protection circuitry in a battery will cut power whenever the voltage gets to it’s lower limit, like around 2.5v.
The LVP in a driver like NarsilM and Anduril will only be active when the driver is active. For instance the light is left on at a low level. When you turn off the light, the MCU goes to sleep to reduce parasitic drain and the LVP is not working. Usually the parasitic drain, even with a lighted side switch, is so low it will take years to run down the battery, depending on the light model, of course.
hi, if I put this uv glass in my regular convoy s2+ will it work as a uv light?
ok trying to answer my own question. if i get that glass and this bead
https://www.aliexpress.com/item/33052474666.html?spm=a2g0o.cart.0.0.234a3c006RDpIs&mp=1
I already have a convoy s2+.
so I think I reflow the solder on the board. twist it out. reflow the solder on the LED. remove. then solder the bead to that board. switch out the glass. then screw it all back together and solder the board back?
seems simple enough. am I missing something?
thanks everyone.
Yes, but it won’t be very bright.
First you need to make sure your S2+ driver will not burn up that led. Ad says no more than 0.5A from driver. If you have the 8x7135 driver, you’ll need to remove all but 2 of the 7135 chips. 0.7A is probably okay.
It’s better to buy the led on the 16mm mcpcb so you dont have to reflow anything.
You won’t need the glass lens if you have the UV led.
cool. thanks. appreciate the help.
if I wanted to upgrade a tail switch for a tail clicky, is the PCB the upgrade or the switch itself.
if it is the switch can someone point me in the direction of a switch that would be an upgrade to a standard convoy tail switch?
ive ordered a few of these PCBs
https://oshpark.com/shared_projects/TCY22964
I’m not understanding you. A “clicky” is a type of switch. You want to change a switch for a switch and have it be an upgrade?
Can you be more specific, what light is it?
I just want a switch I can run high amps through without issue, I have ordered the switch PCBs do I need a different or ‘upgraded’ switch or would say the standard switch from the convoy L6 suffice.
The standard L6 switch seems to hold up really well to like 18 amps or more. The weak part of the mechanical switch is the contacts. Whenever they close you get a power surge and maybe a flash. Not much, but it can build up carbon residue or something which adds resistance.
I’ve got spare L6 switches, but my original never had any problems. I swapped a new one in and measured no difference in lumen output.
If you want something really robust, Lexel was offering a FET based switch, but it doesnt fit inside the light, it mounts outside it.
For a more conventional design I’d stick to the stock switch.
I dont know of any upgrade version to the L6 switch, but you might ask on a L6 thread.
Potted lights? Is there a list somewhere of what lights are potted? Does it really make much difference or is it still pretty much the luck of the QC draw?
I ask this as I have been playing a lot with my new th20 lately and of course have dropped it a couple of times on concrete. Other than the physical dings there are no ill effects and frankly with my experience with Thrunite I don’t expect any. Perhaps I have just been lucky and perhaps Thrunite has decent quality control but isn’t the engineering of how the pill is put together and mounted a significant factor for at least what should be likely reliability? Are Thrunite lights potted? Seems quite a few members mod the th20 specifically to get a different emitter so this should be a known thing. All I know is they have excellent thermal management and hold up to drops. This could be because of potting? There is so much I don’t know.
Could someone differentiate between the pros of Emisar D4SV2 vs D4V2, please? 
Thanks for your help JasonWW
I think these would be the main differences…
No, a regular led does not emit UV, a filter that selects for UV will leave no light left at all.
With most UV leds, very likely with this one as well, the filter is a very good idea, you do need it, because it filters away all of the visible stray light that these leds emit together with the UV light. Without a filter it can only be used for photochemical curing, with a filter it makes the UV flashlight suitable for observing fluorescent stuff.
Are you sure? I thought I saw people installing these over white leds and it has a very weak UV output.
If they block everything, what is the point of them?
My UV light doesnt use a filter and it’s great at showing fluorescing objects. I do see some visable light on certain objects. Is the filter supposed to block this visable light?
Personally, I would suggest that people just buy a good quality UV light from someone like Sofirn or Convoy. It’s going to be way more powerful then the LED mentioned above.