The Lagoon SIXTY 5 sailing catamarans are designed ex shipyard to operate one or two diesel generators for larger electrical consumers. We regularly equip these vessels with a large customised solar system, a lithium battery storage system and high-performance inverters immediately after delivery. The energy management on board is automated and optimised with Victron Energy equipment so that even large consumers such as the air conditioning system can be operated independently of generator noise.
Modification work and preparation
In preparation, our boat builder works with the electricians to convert the battery boxes and adapt the AC and DC cabling for the new load situation. Distribution cabinets, cable labelling and the main DC distribution are prepared in the workshop in Austria to minimise installation time.
Energy Management
The biggest challenge for the energy management on board is a 120BTU chiller air conditioning system, in addition to the electrical kitchen equipment, 230V water makers and other small consumers are operated. On the 24V side, there are larger consumers such as electric winches and anchor winches, but these are easy for the LiFePO4 batteries to cope with.
The AC loads are covered by three 5kVA Victron Quattro inverter/charger combi units connected in parallel. These not only offer 15kVA inverter power and up to 30kW peak power for starting currents, they also have an integrated transfer switch that switches between shore power, generator and inverter operation without interruption. This represents a considerable improvement in the situation on board: From the factory, manual switching between the power sources is required.
Another advantage of this system is the PowerAssist function, which actively limits the current drawn from the shore power or generator and covers peak loads via the integrated inverter. This effectively prevents the generator from being overloaded or a blown fuse on land.
For the expected high currents of up to 1000A, the Victron Lynx Smart BMS was installed in the 1000A version and combined with a customised DC distribution system. This allows the use of NH fuses that can reliably disconnect the high possible short-circuit currents of a lithium battery in the event of a short circuit. The Lynx Smart BMS combines a battery management system (active control of loads and chargers) with a battery monitor, a contactor for disconnecting the system and pre-charge electronics that pre-charge the capacitors of the inverters before switching through, thus preventing sparking and high switching currents.
As the Quattro units only allow 230V input, most vessels are equipped with 5x Phoenix Smart IP43 chargers to give two benefits: Multivoltage charging, basically accepting any shore input voltage and frequency, and faster charging in 230V/50Hz countries, using two separate shore power connections simultaneously.
All components are connected centrally to a Cerbo GX using VE.Bus or VE.CAN data cables.
Photovoltaics
In co-operation with SOLBIAN Solar, several variants of the solar system for the Lagoon SIXTY 5 have now been developed for the hardtop and saloon roof, depending on customer requirements. The most powerful system currently available delivers a peak output of 3,254Wp, which provides a daily yield of approx. 10-15kWh per day in the Mediterranean in summer. This PV system is sufficient, for example, to operate the air conditioning system in ECO mode for 2 hours; without air conditioning, the entire catamaran can usually be operated independently.
The customised solar panels are fully walkable and have a non-slip textured surface. All cabling is concealed beneath the modules so that the system is perfectly integrated into the lines of the ship. The system on the hardtop in particular is virtually invisible from the outside; this part already supplies 1,446 Wp.
The Victron SmartSolar MPPT charge controllers are networked with a VE Smart Network via Bluetooth and also communicate with each other via VE.Direct connections using the Cerbo GX. This networking allows them to charge synchronised and can also compensate for any voltage drop on the cable to the battery, which prevents the solar controllers from influencing each other. As we use way more VE.Direct connections than the Cerbo can supply they are connected to powered USB hubs via VE.Direct USB interfaces.
Monitoring
All data collected from the components - including tank and temperature sensors - is gathered at the Victron Cerbo GX, which not only displays it graphically on a GX Touch 70 and the Raymarine chart plotter: It is also connected to the Victron VRM portal via the Internet. The owner can use this to access all data and receive alarms if there is a problem on board. Furthermore, our technicians can access the system via the portal and, if necessary, install updates, change configurations or view data records.
In addition, the crew receives an audible and visual alarm signal in the event of a critical charge level before the batteries are switched off, which can be muted using a customised control panel.
Technical data:
Storage (24V, 70kWh): 14x LiFePO4 Smart 25.6V/200Ah-a
BMS: Lynx Smart BMS 1000A
Inverter/Charger: Quattro 24/5000/120-100/100
Additional multivoltage chargers: 5x Phoenix Smart IP43 24V/25A
Monitoring: Cerbo GX with GX Touch 70
MPPT controllers: 9x SmartSolar, various models
PV: 3,254Wp SOLBIAN Solar
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