How we power our off-grid floating home

Aboard the Seawind 1160 Lite catamaran SV Sea Moon, Australian cruisers Scott and Sandy have spent years voyaging across the Mediterranean, demonstrating how modern marine engineering can transform an offshore cruising vessel into a self-sufficient floating home. Operating without fossil-fuel cooking gas or reliance on dockside infrastructure, the crew behind Sailing Sea Moon have refined an off-grid electrical architecture supporting complete domestic comfort at remote anchorages throughout Greece and the Ionian Sea. From running high-draw induction cooktops and electric ovens to desalinating seawater and powering satellite communications, their installation proves that clean energy can eliminate compromise from blue water cruising.

Through thousands of nautical miles logged between the anchorages of Paxos and the fairway of Gouvia Marina in Corfu, Scott and Sandy tested their systems under conditions ranging from summer Aegean heatwaves to overcast autumn gales. Their vessel’s electrical capability rests on three integrated engineering pillars: massive lithium iron phosphate storage, an unshaded solar generation arch, and heavy-duty AC inverter infrastructure managed through central digital telemetry.

Lithium Energy Storage and Cerbo GX Orchestration

At the core of the marine electrical platform engineered aboard SV Sea Moon, the crew of Sailing Sea Moon installed a high-capacity lithium battery bank optimized for off-grid solar harvesting and demanding liveaboard cruising. The primary storage bank comprises five 12-volt Victron Energy 200-ampere-hour Lithium Iron Phosphate (LiFePO4) batteries connected in parallel, delivering 1,000 ampere-hours of total nominal capacity at 12.8 volts. Because LiFePO4 chemistry permits deep cycling without voltage sag, the system provides roughly 750 to 800 ampere-hours of usable power for daily offshore living.

Each battery incorporates internal BMS electronics with Bluetooth monitoring to track cell balance and temperatures. Heavy DC conductors route through busbars to an industrial master disconnect switch, while automated protection is coordinated by a Victron Cerbo GX processor. The Cerbo GX enforces a low-voltage cutoff at 25 percent state-of-charge, though Scott investigates supplemental charging whenever capacity reaches 40 to 45 percent. Completely isolated from the house bank is a dedicated 12-volt AGM starter battery for the twin Yamaha 25-horsepower outboards, maintained via a DC-to-DC smart charger.

Solar Generation Arch and MPPT Controllers

Replenishing the heavy lithium battery reserves on SV Sea Moon relies on a dedicated off-grid solar generation arch built by Sailing Sea Moon to support every marine electrical demand encountered in liveaboard life. Fabricated from custom-welded aluminum tubing, the stern arch extends aft of the cockpit to serve a dual role: providing an unshaded plane for three photovoltaic panels while doubling as the primary hoisting davit for their Ocean Craft tender dinghy.

The array features three 450-watt monocrystalline solar panels totaling 1,350 watts peak output. Crucially, each panel connects to its own independent Victron SmartSolar MPPT charge controller. This isolated channel architecture ensures that if the mast, boom, or mainsail casts a shadow across one panel, the remaining two controllers continue harvesting peak solar wattage uninhibited.

All-Electric Galley and Inverter-Charger Integration

Sustaining an all-electric galley aboard SV Sea Moon represents a defining achievement for Sailing Sea Moon, combining off-grid solar capture, advanced marine electrical conversion, and a massive lithium battery system for uncompromised liveaboard autonomy. AC domestic power is supplied by a Victron Quattro 5,000-volt-ampere inverter-charger with an integrated 220-amp battery charger, powering Australian standard 230-volt domestic outlets and European adapters throughout the catamaran.

Eliminating LPG removed dangerous bilge fumes, gas locker corrosion, and the hassle of sourcing foreign cylinder adapters. The galley features an induction cooktop and a Breville convection oven, supplemented by an electric cockpit barbecue. Preparing dinner and heating shower water consumes roughly 150 ampere-hours (15 percent of bank capacity). Incoming AC power passes through a Victron Isolation Transformer, completely isolating dockside and generator grounds to prevent galvanic hull corrosion.

Daily Energy Budget and High-Draw Consumers

Managing daily power consumption on SV Sea Moon requires continuous energy balancing by Sailing Sea Moon, aligning liveaboard domestic appliance use with off-grid solar replenishment and marine electrical monitoring of the lithium battery bank. Continuous hotel loads include dual 12-volt marine refrigerators, a freezer, LED lighting, navigation electronics, and a Starlink satellite terminal converted to native 12-volt DC to eliminate inverter standby losses.

High-draw appliances run during peak midday sunshine. The desalination system produces 120 liters of fresh water per hour while drawing roughly 100 amperes at 12V DC, running for 60 to 90 minutes every few days. During summer heatwaves, Scott and Sandy run the reverse-cycle air conditioner for an hour before bed to drop cabin temperatures from 40°C to 23°C (consuming roughly 100Ah), using 12-volt fans overnight. Normal overnight depletion drops the bank from 85 to 75 percent, which solar fully replenishes by early afternoon.

Generator Backup and Seasonal Solar Dynamics

When adverse Mediterranean autumn weather limits off-grid solar harvest on SV Sea Moon, the crew of Sailing Sea Moon rely on auxiliary marine electrical backup to maintain their liveaboard lithium battery reserves. To handle overcast days and low sun angles without motoring into commercial marinas, the boat carries a portable Yamaha EF2000 inverter generator supplying 1,500 to 1,700 watts of continuous AC power on regular unleaded petrol.

Scott operates the generator on the forward deck to direct exhaust away from living areas, filtering fuel through a Mr. Funnel water separator. Connected to the shore power inlet, the Victron Quattro runs in charger-only mode, feeding up to 220 amps of DC charging into the lithium bank while directly powering the watermaker. The Cerbo GX automatically balances charging as solar harvest fluctuates, delivering five hours of runtime from a three-liter tank.

Marine Lithium Safety and Blue Water Lessons

Rigorous marine electrical standards and preventative fire protocols guide Sailing Sea Moon in safeguarding the off-grid solar infrastructure and primary lithium battery bank installed aboard their liveaboard catamaran SV Sea Moon. Selecting commercial Victron LiFePO4 cells provided certified insurance compliance and proven resistance to thermal runaway compared to older cobalt formulations that historically caused shipboard electrical fires.

Multi-layered safeguards include Class-T fusing, heavy busbars, and Cerbo GX automated disconnect triggers for cell imbalances. Scott identifies portable rechargeable items—such as their Air Buddy dive hookah battery and drone packs—as higher fire risks than the fixed house bank, requiring supervised charging. Furthermore, the system proved its reliability when SV Sea Moon sat unattended on the hard in a Greek boatyard for five months without shore power, maintained in optimal storage solely by the solar arch.

Frequently Asked Questions

Essential technical inquiries regarding the marine electrical engineering, off-grid solar array, and Victron lithium battery bank deployed by Sailing Sea Moon aboard SV Sea Moon for full-time liveaboard cruising.