Not all coaches have the same charging systems and so you will find some charge chassis batteries off shore power or generator and some do not. The only reason some do not install the charging system to keep chassis batteries charged is cost.
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7