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48V or 24V - What makes more sense on a Boat? | Ask The Expert with NIGEL CALDER
June 20, 2026 · 4 min · 5K views
Boat engine with belts and green housing exposed
What this video covers
Jan Attenstedt and Nigel Calder evaluate the trade-offs of installing a 48-volt electrical system versus a 24-volt system on an Outbound Yachts 44/46.▶ 0:09 While 48-volt systems theoretically reduce copper weight by allowing for smaller conductor sizes, they necessitate complex, multi-voltage architectures because essential low-draw equipment like lights and bilge pumps remain unavailable at 48 volts.▶ 0:41 Nigel Calder notes that minimum conductor size requirements—typically 16 or 18 gauge—limit the weight-saving benefits of higher voltages on smaller vessels.▶ 1:22 Although 48-volt systems support high-output alternators, such as the 8 kW integral system, modern 24-volt alternators from American Power Systems now offer comparable efficiency.▶ 3:19 For high-load equipment like bow thrusters and windlasses, installing a dedicated battery bank in the bow charged via a DC-to-DC converter often provides a more practical alternative to a full-boat 48-volt conversion.▶ 2:36 System design requires balancing conductor sizing, equipment availability, and the geographic placement of components throughout the vessel.▶ 2:20
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