I have an Avon Adventure 400 with a Suzuki DV25. I went to use it this weekend but the battery was flat. The battery is a 60ah leisure battery from Halfords and is only a couple of weeks old. The battery has only been used to start the engine once and (presumably) is being charged when the engine is running. There's also a Navman fishfinder connected to the electrics, which was fitted by the dealer when the boat was new. There is no battery isolator switch, and so I am wondering whether it's possible for the battery charge to slowly drain away when the boat isn't being used?
Any ideas/suggestions much appreciated.