The ADD-A-BATTERY is as simple to operate as an ON-OFF switch, yet effectively manages the switching and charging of two batteries from a single charge source

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 when you arrive and OFF when you leave.

• Use this kit when upgrading your stereo or ballast system if your stock setup is only one battery. This kit will allow you to add a second battery to ensure you have enough power and automatically charge both batteries and isolate the accessory battery when engine is off and give you the power of both batteries to start when necessary. 
• Works with almost all boats with alternators 120 Amp and under.