Off-grid solar for RVs and campervans means matching panel capacity and battery size to your loads while respecting roof space, weight, and 12V/24V systems. This guide covers sizing and practical tips for mobile setups.
Sizing: Same Principles, Tighter Constraints
The math is the same as any off-grid system: daily energy use (Wh), peak sun hours, days of autonomy. But in an RV or van you have:
- Limited roof area → cap on panel count and total watts.
- Weight limits → LiFePO4 is preferred over lead-acid.
- Often 12V or 24V → see 12V vs 24V. 12V is common for smaller rigs; 24V for larger arrays.
So you may have to reduce loads (efficient fridge, LED lights, less AC use) or accept fewer days of autonomy if you can’t fit more panels or battery.
Loads in an RV/Van
Typical: fridge, lights, phone/laptop charging, maybe a fan or small heater. List each with watts × hours per day and add 10–15% for inverter loss if you run AC. Use a load list and the WattSizing calculator to get recommended array and battery.
Best Practices
- Mount panels so they get sun (avoid permanent shade from vents, AC). Flexible or rigid panels depend on roof type and weight.
- Secure wiring; use appropriate cable size for system voltage and current.
- MPPT is usually worth it even on 12V when you have more than one or two panels; see MPPT vs PWM.
- Battery: LiFePO4 for weight and depth of discharge; keep it in a ventilated, temperature-stable place.
Summary
Size with daily use and sun hours; respect roof and weight limits; prefer LiFePO4 and MPPT. Use WattSizing to get array and battery numbers, then choose panels and batteries that fit your rig.
