blue sea systems 7649 mini add-a-battery (blue sea systems)
The Add-A-Battery includes a Dual Circuit Plus™ Battery Switch and an automatic charging relay. These components simplify switching and automate charging, so that all you have to do is turn the battery switch ON and when you board and OFF when you leave. For outboard and inboard powered boats. Includes #6011 M-Series mini dual circuit plus battery switch and #7601 automatic charging relay.