My '14 518c is having issues with my 4 year old charger on a 2 year old Duracell AGM battery. The charger will start out like normal but will cycle to a red light and will stay red for a short time and back to yellow and will continue to do this. I put it on another bank and it did the same thing. Took the battery back to where I bought it and load tested it and charged it up. Load test and charged up with no problem. Put it back in the boat and the same thing, the red light never blinks.
Do I need a new charger or is there something else I can check?