Custom High-Output 12V Charging — Volvo Penta D2-75

Not every cruising yacht can — or should — be converted to 48V. This installation shows how a legacy 12V system can be engineered to deliver reliable, continuous high output without compromising safety or serviceability.

• Charging & generation — bespoke 12V alternator rebuild based on a new automotive unit, converted for external regulation and direct lithium charging; 210A continuous output at 12V; regulated by a Balmar MC-618.
• Thermal management — fully water-cooled alternator with a Bowman heat exchanger (freshwater to seawater), integrated via a manifold from the primary engine seawater feed for stable temperatures under sustained load.
• Monitoring & alarms (Maretron) — alternator temperature, current and voltage; battery temperature; Racor fuel filter bowl water-in-fuel alarm; diesel flow (L/h) and range under power — viewable on a cockpit display and at the nav desk.
• Result — a robust 12V charging system capable of supporting modern cruising loads without adding unnecessary complexity.