That D6 looks like a glorious monster of a taillight. Their specs claim 3400 mAh. That, and the overall shape of the light, make me think that they might be using an 18650 battery.

I doubt that DiNotte would be interested in doing so, but I would love to see a similar format, but with a standard 18650 battery that could be swapped quickly in the field. I don't know how much larger and heavier the package would have to be to allow that, but I really like the idea of a great taillight that is self-contained, but that can be restored to 100% capacity in seconds.

That idea is inspired by my Fenix BC30 V2.0 headlight, which uses a pair of standard 18650 batteries that can be swapped quickly and easily.