After installing solar on three different RVs and helping dozens of friends with their setups, I’ve found the perfect boondocking formula: 800 watts of solar with 400 amp-hours of lithium batteries. This combination costs about $3,500 installed but delivers 14+ days of off-grid living with normal usage. Smaller systems leave you constantly worried about power, while bigger ones waste money on capacity you’ll rarely need.
Here’s the math that changed my boondocking game: A typical RV uses 100-150 amp-hours daily (LED lights, water pump, fans, phones, laptop). My 800-watt system generates 400-500 amp-hours on sunny days and 200-250 on cloudy days. The 400Ah lithium bank gives me 320Ah of usable power (80% depth of discharge), providing a solid buffer for consecutive cloudy days without generator use.
The components that actually matter:
- 4x 200-watt panels (I prefer Renogy or Battle Born brands)
- 2x 200Ah lithium batteries (avoid cheap no-name brands)
- MPPT charge controller rated for 60+ amps
- 2000-watt pure sine wave inverter for AC appliances
What surprised me most? Panel placement beats panel quantity every time. I’ve seen 1200-watt systems perform worse than my 800-watt setup because of poor installation angles and shading issues. Mount panels flat for maximum year-round performance, and always leave 2-3 inches between panels for airflow. Hot panels lose 10-15% efficiency, which kills your investment faster than you’d think.