You can measure the standby current with a multimeter if you have one? E switch lights will always draw current even when of but generally should last longer than a few months.
I used the light less than a week ago and I’m pretty sure the battery voltage was right around 3.9 - 4.1 volts. I love the blinkies on my Andruil lights so that’s usually the first thing I do when I turn them on.
On closer inspection today, I found my glow gasket and Carclo Optic melted and fused to the MCPB/LEDs.
I must have forgot to lock it out and the button got held down. It must have an older version of Andruil because I believe TK made that impossible with the newest version. It ramps down if the button is held.
This was an expensive mistake as not only did it kill the battery but it also ruined the optic which has 3 trit vials and the glow gasket. 
I’m going to order those Crown Caps for all my FW3x so this doesn’t happen again.
At least the mystery part of this has been resolved, though. A lesson to all to learn from.
I found my FW3A on in my pocket after hanging up my pants at end of day, several times, on low, before I developed the habit of unscrewing the head a half turn every time I put it away.
“Why are your pants glowing?” is not the best question a flashlight fan can hear from a stranger.
Fw3a has no lvp?
I guess not. Is there a way to tag someone in a post? I’d like to ask TK
’oogled that:
Interesting that the LVP failed here
From the heat?
should measure that bat with a DMM
if there is an issue with the LVP, thats pretty inportant
so whats the standby current drain
How do I do that? It’s a mule right now so I have access to the LED terminals. Just put my multimeter on them?
If the cell got hot enough the internal safety cutoff could have been triggered.
CSI Florida??
Unscrew Tailcap and meaure current between tube and negative cell terminal.
But it’s unlikely this drained the cell imo.
Yeah, the melted optic and glow gasket tell a different story but I’m curious to test it though.
I messaged ToyKeeper with the hopes that she might be able to tell me if I have a bad light.
It seems to be working now but maybe I will keep it mechanically locked out as I thought I had electronically locked it out last time I used it.
That light can’t be mechanically locked out. All that does is cut off the switch control, but the rest of the light (i.e., the mcu) is still powered and functional.
Maybe it’s just me, but if this light melted down on you, I’d want to make 100% sure that it was something careless I did, and not something the light might decide to do on its own again.
I recall there was a “melting down” problem with the Emissar D4v2 in muggle mode, which runs the same firmware. Perhaps this is related? Let’s hope not.
Whoa. Good thing it didn’t catch fire and spew toxic chemicals all throughout your entire house!
It was in the door of my truck. I’m still not 100% sure of what happened because I think I locked it out.
I’ve had that switch get stuck before but it was usually right when the battery went in. The LVP or thermal stepdown should have prevented what happened anyway though so I’m worried about that light now.
Like the man said:
and the question is thrashed in more than a few subsequent comments in that linked thread, including a warning about having a loose sliver of metal in the wrong place cause a rapid battery discharge.