Configuration Decision Matrix
Compare example battery, solar, inverter and charging ranges for day boats, cruising yachts, catamarans and high-energy liveaboards.
| Vessel or use | Daily energy | Storage range to investigate | Solar range to investigate | Typical inverter class | Voltage to evaluate |
|---|---|---|---|---|---|
| Day boat | 0.3-0.8kWh | 1-2kWh | 100-250W | 0-500W | 12V |
| Weekend sailer | 0.8-1.8kWh | 2-4kWh | 300-500W | 500-1,500W | 12V |
| 30-35ft cruiser | 1-2.2kWh | 2.5-5kWh | 300-700W | 1-2kW | 12V |
| 35-40ft cruiser | 1.8-3.5kWh | 5-8kWh | 500-1,000W | 2-3kW | 12V/24V |
| 40-45ft cruiser | 2.5-5kWh | 5-10kWh | 700-1,400W | 2-4kW | 12V/24V |
| 45-50ft liveaboard | 3.5-7kWh | 8-15kWh | 1,000-1,800W | 3-5kW | 24V worth evaluating |
| 40-45ft catamaran | 4-8kWh | 8-15kWh | 1,200-2,000W | 3-5kW | 24V |
| 45-50ft catamaran | 6-12kWh | 12-25kWh | 1,500-3,000W | 5-10kW | 24V/48V |
| High-energy liveaboard | 8-15+kWh | 15-30+kWh | 2,000-4,000W | 5-10+kW | 48V worth evaluating |
| Overnight air conditioning | add 4-10+kWh | often 15-30+kWh total | large solar + backup | compressor specific | 24V/48V |
These are educational ranges. The table is designed to show the scale of systems, not to prescribe a battery size from boat length.
How to use the matrix
If your measured daily use is already higher than the row for your vessel type, follow the energy number, not the boat length. If your peak inverter load is higher than the row suggests, recheck system voltage and BMS current before increasing battery capacity.
The matrix should also be read in reverse. If the boat can physically carry only 600W of solar and has a small alternator, a 15kWh bank may provide impressive reserve but slow recovery. That does not make the bank wrong, but it changes how the boat will be operated.