Eight Batteries Upgrade System Install

As shown above, VitaminSea is a 1996 Hatteras 65 Convertible Enclosed Bridge whose owner regularly cruises offshore, including runs to the Bahamas, and wanted the ability to complete extended passages and remain at anchor without continuous generator use. Based on typical crossing times and onboard comfort expectations, this translated into a clearly defined requirement of approximately 10 hours of generator-free operation while maintaining air conditioning, refrigeration, navigation electronics, and normal hotel loads.

System Load Analysis

To properly size the battery bank, the vessel's real-world electrical consumption was evaluated based on operating profiles typical for a 65-foot convertible. This included air conditioning compressors cycling under cruising conditions, refrigeration loads, navigation electronics, lighting, and general hotel demand. After reviewing expected duty cycles and simultaneous load scenarios, the calculated average continuous electrical demand was determined to be approximately 4 to 4.5 kW under realistic cruising conditions. For a vessel of this size and equipment level, that load range is consistent with normal offshore operation.

Battery Bank Sizing and Runtime Modeling

With the vessel's average load established, the next step was determining the battery capacity required to achieve the 10-hour generator-free objective.

Each EPOCH 24V 230Ah lithium battery provides: 24V x 230Ah = 5.52 kWh.

Initial 4-Battery Proposal

Initially, a four-battery configuration was evaluated as a potential solution.

5.52 kWh x 4 = 22.08 kWh nominal capacity

After accounting for approximately 90 percent inverter efficiency:

22.08 kWh x 0.9 ≈ 19.9 kWh usable

At the calculated operating load:

19.9 kWh / 4.5 kW ≈ 4.4 hours
19.9 kWh / 4.0 kW ≈ 5.0 hours

Even allowing for natural air conditioning cycling and load variation, practical runtime would fall between 5 and 7 hours. While technically viable, this configuration clearly fell short of the defined 10-hour performance requirement.

Final 8-Battery Configuration

Based on this modeling, it became clear that the target runtime could not be achieved with a four-battery bank. To meet the operational objective while maintaining conservative lithium depth-of-discharge margins, an eight-battery configuration was selected.

5.52 kWh x 8 = 44.16 kWh nominal capacity

After inverter efficiency adjustment:

44.16 kWh x 0.9 ≈ 39.7 kWh usable

At a 4 kW average load:

39.7 kWh / 4 kW ≈ 9.9 hours

Under real-world operating conditions with normal load variation, this configuration delivers 10+ hours of generator-free operation, satisfying the runtime requirement with appropriate system reserves and improved voltage stability under sustained inverter demand.

Charging and System Integration

To properly support a 44 kWh lithium bank, charging sources and system control architecture were scaled accordingly:

• 4 x 420W REC solar panels (1.68 kW total array capacity)
• 24V Silent X wind turbine from Ryse Energy for supplemental offshore generation
• Victron Quattro 5kVA inverter/charger (240VAC, 60Hz output)
• Victron Lynx Shunt for DC distribution and precision monitoring
• Victron Cerbo GX with GX Touch 70 for real-time system management

This hybrid architecture ensures stable AC output, controlled charging, accurate current monitoring, and full system visibility.

The Result

The completed system delivers:

• 44+ kWh of lithium storage
• 10+ hours of generator-free runtime
• Reduced generator noise and fuel consumption
• Stable voltage under high inverter demand
• Intelligent, real-time power management

The outcome is a properly engineered high-capacity hybrid energy platform designed around a quantified runtime requirement rather than a simple component upgrade. The vessel can now complete offshore passages to the Bahamas and remain comfortably at anchor with substantially reduced generator dependency, maintaining full onboard functionality while delivering the quiet operation expected during extended cruising.