Yes I am aware that the small roboports are entirely for charging purposes however in my case I have a medium and a small roboport, the bots will all go to the medium to charge and not go to the small at all. If I just have a small roboport with no other roboport the bots seem to never go to it to charge and will just sit idle.
Maybe I am understanding this incorrectly but the bots if given only a small roboport to charge from will never go to it to charge.