The installation of a sophisticated new Lithium-Ion-based AC/DC electrical system is now in process aboard a Westerly 57. As the owner wanted the ability to run his AC watermaker while underway, without having to run the generator, and the boat was already partially gutted for repairs due to a grounding, this winter presented the perfect opportunity and a blank slate on which to do the upgrade.
Assigned to the project are GIBY’s Electrical Systems Tech, Bobby, responsible for the design, and Systems Tech, Jeff, responsible for making the layout and larger batteries fit.
“Lithium-Ion batteries provide the energy density necessary for the task,” says Bobby. “At 400-amp hours/5100 watts apiece, six batteries, together, will provide as much available power as 16 8D AGM batteries, but at 60% less weight. In this case, output from four new batteries will be routed through two 5000-watt Victron inverter/chargers to produce 10kW of AC power at 240 volts. Each pair of batteries will be monitored and disconnected if low or high voltage, or high temperature, is detected. The output signal from the monitoring system is utilized through a system of relays, designed to shutdown each battery charging source in the event of battery failure.”
The installation is nearly complete. Presently, Bobby and Jeff are organizing the control circuitry and wires, in keeping with ABYC standards, and consolidating the new battery banks to just two locations. In the previous setup, batteries were scattered throughout the boat. The new design calls for securing the Lithium-Ion batteries on platforms custom-built by Jeff. The batteries have already been dry-fitted and will soon be lowered into place, permanently, then connected, and tested.
“We will turn on each battery bank and control unit individually, and test the control circuits for each one,” says Bobby. “We’ll test the shut-down of the chargers, alternator, inverter/chargers, and the braking/shut-down of the wind generator. Then we will progressively load the system and check for even current draw from the banks, hot spots, and expected working load.”