Thanks for that information! Sounds like the power mux should work great for my case.
I have attached a bad doodle of what I had in mind.
The battery pack I am using is similar to one of these, and has a micro usb charging port. When connected to a charger the 5V output gets automatically turned off.
I am also worried about the mechanical design and electrical coupling for the dock since I will probably be drawing more than 1A at 5v while powering the raspberry Pi and charging the battery. Definitely don't want to burn down the house with my robot. Any pointers on robot charging dock design would also be appreciated.