Blue Sea Systems 120A Add-A-Battery Kit
Adding a second battery to the electrical system prevents the unintended discharge of the engine start battery.   Blue Sea Systems popular Add-A-Battery kit was primarily designed for boats with alternator output of 120A or less.   When installed, the Add-A-Battery isolates the start battery from the house loads which prevents the discharge of the start battery. The Add-A-Battery offers a simple way to control the charging and battery switching of two battery banks. The E-Series Dual Circuit Plus Battery Switch simplifies the switching while the SI-ACR automates charging between two batteries.