OK this is my first time on here so I apologize if I'm violating any protocol. Here's what's happening and I'm wondering if anyone else has ever ran into this problem and could tell me how they permanently solved the problem. I have a 2000 310 Sundancer and last 4th of July my batteries went dead. So I went and purchased 2 new batteries and this seemed to solve the problem EXCEPT 30 days later the new batteries went dead so I charged them and everything seemed to be ok but not true as it turns out. So we put the boat up for the winter and then this spring we tried to go out but once again the the port side battery is dead. So I hired a shop to diagnose the problem and fix the problem permanently. Well $500 later they tell me they replaced a fuse and everything tested fine. Well prior to Memorial weekend we go to the boat and the port battery is dead again so I charge it and we go out for the day. Needless to say over the weekend I replace both batteries again and things seem to be going well for now. However the following week, after replacing both batteries, the port battery goes dead again. Well I complain to the repair shop but can't get my calls returned. Well now I don't want to return to the shop because I can't and don't trust the shop to properly fix the problem. So if somebody could share their experience and or advice on what to do or how to fix this problem I would be very grateful.