Draining RV battery

Could be bad batteries as 2oldman said, bad or corroded connections,not charging the battery fully before you disconnect, something draining your battery etc. Start by posting the type, age and number of batteries you have in the MH. What type of charger do you have and how many amps does it charge at? Is it just your starting battery that goes dead or your house batteries also? If you answer these questions you will get more help in narrowing down your problem. Charging your cell phone is not your problem or being parked all day. Will good batteries you should be able to go 5 -7 days with just refer and water pump. Your aux start switch will work if your house batteries are good and fully charged or closed to being fully charged.