30ft Sailboat — Weekend Cruiser
sailboat · 12V system
Basic coastal cruising setup with essential navigation, lighting, and comfort appliances.
Daily load
1,735 Wh
Daily Ah
145 Ah
Battery
400 Ah LiFePO4
Solar
600 W
Load budget
| Load | Watts | Qty | Hrs/Day | Wh/Day |
|---|---|---|---|---|
| Navigation LightsCRITICAL | 15 | 1 | 12 | 180 |
| Chartplotter | 25 | 1 | 8 | 200 |
| VHF Radio (Standby)CRITICAL | 5 | 1 | 24 | 120 |
| 12V Marine Fridge | 45 | 1 | 16 | 720 |
| LED Cabin Light | 5 | 4 | 6 | 120 |
| Bilge PumpCRITICAL | 30 | 1 | 0.5 | 15 |
| Autopilot | 40 | 1 | 8 | 320 |
| Phone Charger | 10 | 2 | 3 | 60 |
Battery bank
2 × 200Ah in parallel
Your daily consumption is 145Ah. With 2 days of autonomy, you need 289Ah of usable capacity. LiFePO4 (Lithium Iron Phosphate) batteries should only be discharged to 80% depth of discharge, so you need 361Ah of total capacity. We recommend a 400Ah bank (2 × 200Ah in parallel), giving you 320Ah of usable capacity — enough for 2 days without any charging.
Solar array
3 × 200W panels · 63A charge controller
Your daily consumption is 1735Wh. With 4.5 peak sun hours, a 75% system efficiency factor, and LiFePO4 (Lithium Iron Phosphate) round-trip efficiency of 96%, you need 535W of solar panels. We recommend 3 × 200W panels (600W total). This array will produce approximately 169Ah per day at 12V. You'll need a charge controller rated for at least 63A. MPPT recommended — higher efficiency at this array size.
Design your own system
Build a load budget, size batteries, solar, and wire runs, then share your design here too. Free account — no credit card.
Start your free design