Complete RV Solar Battery Planning
Daily Energy Use
A reliable RV power system starts with daily energy use. Lights, fans, pumps, laptops, fridges, and chargers all draw different watt hours. This calculator groups direct current loads and alternating current loads. It then corrects alternating current loads for inverter loss. That step matters, because batteries supply direct current power.
Battery Storage
Battery size is not only total capacity. Usable capacity depends on chemistry, depth of discharge, temperature, and reserve. Lithium batteries often allow deeper discharge. Lead acid banks need more headroom. Cold weather can reduce available storage. A reserve setting keeps extra energy for cloudy days, late arrivals, and emergency use.
Solar Array Sizing
Solar array sizing also needs derating. Panels rarely produce rated watts all day. Roof angle, heat, shade, cable loss, controller loss, and dust reduce harvest. Peak sun hours simplify these effects into one daily value. The calculator combines sun hours with panel derate, controller efficiency, and charging efficiency. It then estimates required array watts and panel count.
Controller and Wiring Checks
The result also checks charge controller current. This helps avoid installing too much array for a small controller. The current estimate is approximate. Always compare it with the controller manual. Wire size, fuse size, and disconnect ratings must follow electrical rules.
Trip Planning
Use this page during early design and trip planning. Enter conservative loads if you camp remotely. Increase autonomy days for winter trips. Lower peak sun hours when parking under trees. Add more reserve for medical devices or critical refrigeration.
Balanced Design
A good RV solar design balances comfort and weight. Too small a bank causes deep cycling and short runtime. Too large a bank costs more and may recharge slowly. The best system matches your appliances, travel style, climate, and charging sources.
Save Your Results
Review the CSV or PDF summary before buying equipment. It gives a simple planning record. Share it with an installer, or keep it in your build folder. Recheck the numbers after adding new appliances. Small loads can become large when they run for many hours. Smart estimates make boondocking calmer, safer, and more predictable.
Extra Charging Sources
Add shore power and alternator charging when available. Those sources lower solar stress. They shorten recovery after storms. Still, battery capacity remains the buffer between loads, weather, and charging during each parked day.