I’m going live my experiment over the next six months or so by sailing down the Pacific coast of Baja and cruise the Sea of Cortez.
With a nod towards Henry David Thoreau’s spirit, I am over-simplifying everything.
Instead of adding more batteries, upping amp hours, and trying to install more and more solar panels to keep everything charged, I am going with a single 12v, 100 amp-hour Battle Born Battery that’s charged by a single, 110-watt Sun Power flexible panel and a Genasun MPPT charge controller. So far, it is keeping the battery at a comfortable 95%
Another 110-watt panel feeds the 48v, 50 amp-hour bank (four, 50 amp-hour batteries in series). Connecting the panels in parallel can boost the solar charging of the 48v side as the Genasun MPPT controller can handle that (and a panel more if needed).
This works as the electrical demands aboard a 24-foot sailboat are minimal (chart plotter, VHF, depth sounder, Maertron wind instruments and bilge pump if needed). The 48v side provides 4-hours of thrust and acts as a 3.5kw generator when sailing over 5 knots. The 48v bank can also put a float charge of 13.8v into the 12v via a DC/DC Sevcon converter.