Managing all your batteries while boating is a cinch with an automatic charging relay system such as the Add-a-Battery kit ($137.99, westmarine.com) from Blue Sea Systems (bluesea.com). Such a system allows charging current to flow to both starting and house batteries automatically, without your having to remember to throw a switch, yet prevents inadvertently draining the starting battery while using house loads (stereo, fish finder, plotter, etc.) that might leave you dead in the water.
While there are a number of ACR configurations, here’s how to set up a basic two-battery system on a single-engine boat, using the Add-a-Battery kit.
Time to Complete: 2-3 Hours
Skill Level: 2.5/5
Tools and Supplies:
*Blue Sea Systems Add-a-Battery kit
*Marine-grade tin-plated copper wire/cable for + and – connections
*Marine-grade fuses (4)
*Marine-grade tin-plated copper common bus bar
*Marine-grade crimp connectors
*Cable clamps and tie-wraps
*Power drill and drill bits
*Socket wrench set