Marine Battery Runtime
Battery runtime depends on capacity (Ah), load, and depth of discharge. Lead-acid and lithium have different DoD limits. See our marine DC wiring systems for the full design guide.
Basic formula
Runtime = usable Ah ÷ load current. Lead-acid: limit to 50–80% DoD for longevity. Lithium: 80–90% is common. Use our battery runtime calculator.
Marine context
Fridges cycle on/off — use average current over 24h. Navigation and lights: sum continuous loads. Size the bank for worst-case consumption (e.g. overnight). Add margin for cloudy days if solar is primary recharge.
Integration
Battery-to-bus wiring must be sized for charge and discharge currents. Check calculate voltage drop and wire gauge calculator. Fuse the battery bank output — use fuse sizing calculator.