Are there any hosts with charging built in?

I’m looking for a host with charging capability built in. So, I guess that would probably include the driver. I want to build a few of them, so I’d like it to be just a host to make the build process easier. I’ve yet to find one, but if there is such a host it doesn’t really matter what battery size as long as it’s single cell.

They’re usually so intertwined with the driver that it wouldn’t be much of a “host” anymore, just a flashlight minus the LED.

Thanks. Sort of figured as much. Thought there just might be something I had overlooked.

Someone should market a tail cap accessory with charging. Doable?