Recently went to check the condition of the batteries and found the starting batteries almost dead. I found that there is a digital echo charger made by Xantrex that quit working. Unfortunately if it get a little damp it will fail and is not repairable. It supposed to have a solid green LED light lit when charging, flashing means a fault exists and no LED means it is fried. I have another one coming and it will be here Friday.
I like to spray the batteries once a year with cleaner and hose off then coat the terminals with sealer so I may of caused it to a certain extent. Other cause is the batteries are in a area where salt spray can get to it and corrode it. I'm going to see if I can relocate it near the inverter where it stays dryer and has a fan and filters to keep it clean and cooler. I will keep you posted what I do.