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Air Conditioning without a Generator

Have you ever wished you could sleep comfortably without the droning of a generator keeping you awake? It is now possible thanks to the high storage capacity of Lithium (LiFePO4) batteries. Our service department recently completed a new system installation on a Leopard 440 catamaran that allows the cruisers to run the entire electric service panel from two inverters. Now, the owners can run both air conditioners, water heaters, microwave oven, 12 volt battery charger, and more, without running the yacht’s generator. Here is how we accomplished this:

We chose Victron Energy’s Quattro inverter/chargers as the heart of the new system. We added 48 volts worth of Lithium batteries (total about 20 kWh capacity), along with 2.2 kW of solar so the owners can keep generator use to a minimum.

It is getting crowded in here!

Since this particular Leopard 440 is equipped with twin 30 amp shore power connections, we opted to use two 5000 watt inverter/chargers – one for each shore power leg. We configured the Quattro Inverter/Chargers in a master/slave setup that allows the battery management system to handle the power flow. We chose Victron’s 24 volt Smart Lithium batteries to keep connections to a minimum. The 48 volt battery system allowed us to keep cable sizes down, which allowed us to run all cables through the factory conduits – a big help with keeping everything secure!

One BIG caveat with choosing a 48 volt battery system is the availability of switches, fuses, and breakers that can handle the voltage. Don’t make the mistake of using equipment rated for just 48 volts! While the NOMINAL VOLTAGE of the system is 48 volts, the ACTUAL VOLTAGE is between 53 and 58 volts!

Rather than upgrade all the boat’s existing 12 volt systems to 48 volts, we chose to add monitoring to the 12 volt house bank. Now, all the systems are monitored in one place! We kept the installation simple by using the existing 12 volt battery charger to keep the house bank full.

The Victron Cerbo GX with touchscreen display provides clear, graphical information on what is happening with the system.

We selected LG 375 watt panels for the solar arrays. We designed the solar strings in series for maximum charging efficiency, and separated the port and starboard panels into two strings. A custom stainless steel frame keeps panel shading to a minimum.

Please contact us if you have questions, or would like a quote for going silent.

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