I think the Wowtac A6 is smaller in volume and has built in charging. It is ever so slightly longer than the FW3A but smaller in diameter.
https://www.amazon.com/dp/B08C4MZTFV?psc=1&ref=ppx_yo2_dt_b_product_details
I would change my mind in a minute if the USB can be made to allow the light to be hooked up to a computer to program Andruil with a PC program and not that dang single button.
So then the USB would function to: (1) Charge the light, (2) Charge your phone, (2) program the light with PC software.
That would be a game changer.
There is absolutely positively no reason this cant be done. It may add $1 to the cost of the light.
Maybe in the future. Right now manufacturers are not interested.
But putting Windows 11 on your flashlight won’t end well 
Thanks! I’ll check it out.
I think built-in charging functionality has gotten better. It has certainly gotten smaller!
Those people lamenting of increased light size are parroting old arguments. Yes, there’s some increase, but relatively? Not much, for the most part. I have a Sofirn SC01 and Olight i1R EOS that are micro lights with built-in charging. They work great and I don’t see appreciable bulk. Also both have screw heads that cover over the charging port, so no worries about moisture compromise. My Aurora A5 & A8 have rubber plugs. The A8 is nicely tight, but the A5 is a little too easy to remove for my preference. My Niwalker ET2 has a really nicely fitting USB-C plug. There’s no way that’s coming out by accident and I’m pretty confident it’s puddle proof.
If one is going to use a light frequently in a wet environment, then yes it makes sense to go with non-charging or a magnetic charging port.
I get that it has gotten smaller, and micro is even smaller than usb-c, but when I think about the lights I carry regularly, integrated charging would ruin them or add appreciable bulk to where suddenly I’d probably be carrying one of my other lights of a similar size. Where in a D25C is there space for it? Where in FW3A, DQG Slim AA, SC6x series? Sure you’re adding, what, 5mm length or something, and to a lot of people that’s not much. But if you set down a 5mm longer, usb-c charging FW3A next to the one I own, I’d carry the one I own…
On larger lights, it matters far less. A lot of larger lights have so much extra space in them that adding charging just fits into already-wasted space. Or, the light is already not-pocketable so nobody minds a minor length increase.
D25C - 2.9 inches long without charging
Thrunite T1- 2.7 inches long with charging.
It can be done.
no
Yes, because if I don't have spare batteries or a charger behind me, I can still recharge my flashlight. In this regard, but why is there no 14500 battery flashlight with built in charging?
I think they don’t want someone trying to charge an AA alkaline that could wind up in it.
To begin, the T1 has a side switch, which will be shorter. Battery length is close enough and the T1 actually takes long (protected) 18350 which is longer than 16340 to begin with.
I can never mod the T1 driver. But my D25C has a 17mm from MTNE swapped in with the exact functions and firmware I want.
There’s a reason I don’t own a T1
Funny enough, the other D25, boruit/whatever brand sofirn calls it D25S, is a great example of a light I love with integrated charging. It’s “small enough” with charging, in a form factor where I care more about weight and leverage than size, and because the charging circuit is separate I’ve swapped in Anduril Fet+1 drivers on it and my similar D10 headlamp. It also has the lovely, behind-threads charging design where I’m not worried about a rubber flap or water ingress.
I’m still salty about my LT1 losing its flap. It wasn’t even treated roughly.
I think you may be guilty of some hyperbole but the points you mention are consistent with my observations.
Don’t get me wrong, it’s great that we have manufacturers (Simon, Hank) that can fulfill nearly any demand, and others that are doing things mostly-right to where most users don’t need to mod (or not more than emitter swap) their lights. But a lot of lights are getting harder to mod. I mean even a D4v2/KR4 is intimidating to emitter swap because of all the aux light connections and the tight fit.
What you say also makes sense. The more features already in a light then people might feel less inclined to open it up.
I recall reading someone had 1 out of 4 18650 die inside an LT1. Now imagine that happens but you don’t know and you start pushing a charge through it. Not goods. I would prefer not built in but will still buy it.
Then again, I’m heavily invested in chargers 
No. Never ever use it.
Prefer not to have it but it wouldn't prevent me from buying one with it.
For me, this is basically a must-have.
I have enough chargers, but to just grab a USB-C lead and plug it in is easier than pulling out a charger and find a space for it.
If you have a charger always set up, it’s no big deal, but I haven’t.
Wouldn’t prevent me from buying a light, though. Just micro USB is a no go these days.
I do not trust the charger on my batteries or for fire concern reasons. Don’t like the seal on the port for leakage and at night it confuses me which one is the switch. I glued one closed already and considered de-soldering another one. I have to pay more for something I do not want. 
One thing I really don’t like:
Cells with built in charging that don’t fit in my charger! 
At times the cell’s USB charging can be handy but for a few 21700 lights it means I can’t just chuck them in a bay along with other cells.
The worst culprit is a 21700 cell with micro USB charging, which I can’t even charge at 1A.
I basically never want charging on the cell. It makes the cell larger or requires a smaller cell (lower capacity and discharge) be used. I’m still taking the cell out, so I may as well use a proper charger. To me, it’s just silliness.
I’ve come to appreciate it in work lights, or I suppose for any light that I drained on a daily basis. Lion cells just aren’t made to be handled frequently, especially in work environments.
That said, I was turned off when my Acebeam EC65 smoked from charging. Even if the light still functioned, it would bother me to have a flashlight with a broken charging port. So I only want it on everyday heavy use work lights. I don’t want it on a camping light or casual light that I use for 2 weeks without charging.