Battery question new to RV

[SAman]

Hi, I am new to RVs. Picking up an 01 Rialta, seller said inside batteries both need replacing.
What are those used for?
How do they charge?

I will start with RV parks plugging in for power. Do I need those batteries while driving? I know it has a battery under hood for the actual engine, so will those back batteries run the back part while driving?

If I go out to the RV in my driveway will the insides light power from those two batteries?

Thanks in advanced, looking forward to learning all about the Rialta.

[SteveJ]

Good tutorial here:

The 12volt Side of Life (Part 1)

[mloganusda]

Your coach batteries power all your inside lights, water pump, and heater blower motor. The coach batteries are located in the floor behind the front seats. You need the key to open the cover over the storage batteries. The replacement batteries need to be deep cycle storage batteries. Here is a URL for info on all Rialtas.
Winnebago Rialta Motor Home

[SAman]

Thanks everyone, great info.