Building and Wiring a 3 bay Battery Box on a Small Sailboat

We'll cover battery relocation, designing and building a battery box, wiring and setting up breakers, and then attaching to the boat's electrical system. The box contains 3 AGM 12V 100Ah batteries (Group 30H size, 12.1"L x 8.5"H x 6.7"W). A 780Ah Optimum Start Battery is housed in a separate box behind. At the end, I include some sailing video on our son's Pearson 365 ketch as we enter the Chesapeake Bay from the Atlantic Ocean.