Solar charger but still dead batteries

Need a lot more info to help. Age and type of batteries? How many amps does your solar charger put out? How many amps does your built in charger and how long have you charged from shore power? Have you checked your parasitic amp draw with everything shut off? Do you have a battery shut off switch? How are you checking your batteries to know they are fully charged? From your post it sounds like your batteries are going dead in a week after charging is that correct? Have you checked the water level in the batteries? If you reply to the questions you will get better answers to your battery problems otherwise you will just get guesses.