Personally, I think this is a suboptimal compromise. If you are already unscrewing it - might as well just put in a fresh cell. And getting grease on the USB cables would be no fun either.
The best solution to me is either no USB for simplicity, cost, and reliability - Or an easily accessible port. For the latter, I prefer it to be on the tail (e.g. Sofirn SC33), so that it is independent of the driver - for reliability and easier modding/driver replacement.
Idk, it saves me packing an extra external charger if I’m on the road. Which is what I was originally thinking of when I made this post. I think it’s a fine option personally. I would definitely prefer having a charging port over no charging port.
I’ve never had an issue with grease. I grease up all my lights too.
You know you’re right. They do look very similar. Maybe the same OEM?
Yes, I reviewed that in the banggood thread last year I think. A terrible light, except for the charging port. That was by far my favourite part about the light. But I ended up giving it away because the switch was just God awful.
And that solidifies why I think it would be a good option. I’ve already tried it and really liked it.
True. But what I like about this solution (correct me if I’m wrong) is the fact it allows to use regular drivers w/o usb charging port…
Yeah, makes sense.
What about a solution like on the Acebeam P18?
Yes, as I understand it, the dongdonghai is exactly the same way. Basically the head when you unscrew it is exactly the same as any mechanical switch convoy head.
The charging port is built into the battery tube…
So it allows you to use regular driver
I asked the dongdonghai seller and they said, yes you can even use the regular convoy drivers it works fine. .
That is actually nice! If only it would not make the light longer and heavier.
I like those too. If Simon could design those that would be awesome.
This provoked an idea of “charging battery tube” which you could add to the flashlights w/o that function.
Just imagine there’s new battery tube for oldies like Convoy C8, S2+, L6, etc, etc… That would be a major upgrade for still well performing lights. And required just buying additional tube.
Edit: or even better - design an additional ring with charger which you just add between the head and the tube.
Well… this solution gives many hopes 
I like those ideas as well. I’m sure I’ve seen that implemented in some other flashlight before. But I can’t remember the model.
That sounds plausible, similar to how many Convoy and Pioneman lights are similar.
I really like this idea, actually. It doesn’t look like it would be too difficult to implement either for a lot of lights either, as many share the design of the tube.
Hard part might be making it compatible with lights using a positive post, instead of a spring.
It could use the slim charge circuit normally used in USB-C charging protected cells, but with bypasses for the light’s current path
In SC33’s case charging circuitry is on the driver. I’ve taken one apart and studied it.
I could not possibly agree more. It is essentially impossible for me to driver-swap any light with classical integrated charging.
I think the adapter ring would add more length than if integrated into the tube
I’m all for more options so I have no reason the object to this, but personally I’m not a fan of the spacer method (it’s unnecessary long in what is already an already long light). I’d like there to be an 18500 tube available so people could make a spacer-less triple and use an 18650 with an 18500 tube.
I like that concept, but it will need the longer threads in the flashlight’s head, so we can screw in the pill deeper.
Of course, making the thread longer is much more clever solution than adding a piece of metal just to fill the space (although, more metal — more heat absorption). Or… the head itself may be shorter — just as in freshly-released T5 compared with T3.
I agree that making the thread longer is the easiest solution. Although for modders, it’s easy to remove some of the threads from the pill to allow it to screw in deeper. The difficult part for modders like me, without a lathe, is addressing the body tube, so an 18500 option would be great.
Regarding the heat absorption of a spacer - I’ve been curious about that, i.e. the concept of “thermal mass.” More metal will absorb heat no doubt, but in order to help with performance it also needs to be able to release that heat away from the light. A spacer would need to have tight contact with the head wall in order to release heat (I don’t know if that’s the case).
Edit: actually I think it would be really cool if he offered a separate “head” for the S2+ that used a shelf and removable bezel - basically a scaled-up T2/T3 head. The LED cavity could be sized for a triple with standard optics. Sell it as a complete light, a kit with driver/LEDs, and just the head.