What is the water resistance rating for these? I see they have the charging ports covered with rubber plugs and it otherwise LOOKS waterproof... ?
Those covers are for port protection only.
What is the recommended charging procedures for this product?
The Kuadrant charges from any USB power source including wall adaptors, car chargers or computers. Plug the small end of the charging cable into the Kuadrant and the large end into the charger. A flashing green light inside the charging port indicates charging is in progress. That light goes out once fully charged.