i guess biggest question is, what are you trying to achieve.
you want 110v on the bus with no genny or shore power
so you need to turn 12v into 110v
you need an inverter for this job this type of equipment
http://www.ebay.com/itm/NEW-Cobra-CP...item519dbad59c
your alternator would charge your batteries, and then the invertor takes 12v from the battery and turns it into 110v
you need to determine power needed
example:
inverter 1 amp guess for 24 hrs so you need 24 AH to power it
fridge pulls 5 amps average for 24 hrs so you need 120 AH (amp hours)
tv pulls 2 amps average for 6 hr so you need 12 AH
toaster (700w) about 6/7 amps for 1 hr (lots of sandwiches in an hr
) so you need 7 AH
right now you need 163 AH per day to power those products for the specified time so using that number I made up not letting bateries get below 50%(deep cycle)
you need a battery bank with about 330 AH rating.
So after you have used that 163 Amps you need to get them back into battery bank for the next day this can be done by solar,battery charger,generator, wind power or shore power
normally you can charge your batteries with the alternator, it wont give a good charge like controllers do tho,so you need to provide 163 amps back to the batteries
run numbers and see how much power you really need; if the bus is running and the alt is charging the excess charge will help knock off some of the lost AH
I just used made up amp draws for the conversation