RV solar calculator
Size an RV solar starting point
Translate estimated daily amp-hours into solar array, battery-bank and charge-controller targets. Real output changes with season, latitude, shade, panel angle and weather.
Use a battery monitor or add the daily use of lights, fridge, fans, electronics and inverter loads.
Use a conservative seasonal figure for where and when you camp.
More autonomy increases battery capacity; it does not guarantee solar recovery.
Use the actual manufacturer limits for the battery you choose.
This helps frame inverter size; add headroom for motor or compressor surge.
Controller current falls as system voltage rises, but every component must match the architecture.
Your planning range
—solar array target
—battery-bank target
—minimum controller current
Assumes 25% harvest/system-loss headroom and the selected usable-battery percentage. Verify panel open-circuit voltage, controller limits, conductor ampacity, fusing, disconnects, inverter surge and manufacturer instructions.
Solar output is not the same every day.
Design for the difficult season
Summer desert output does not represent shaded forest camps or low winter sun.
Plan more than one charging source
Shore power and properly designed alternator charging can make an RV system far more resilient.
Protect every conductor
High-current DC systems require correct wire sizes, fuses, disconnects, terminations and secure mounting.