48V Solar Calculator
Size a complete 48V solar system for bus conversions, skoolies, and large off-grid builds. Get panels, battery kWh, inverter, MPPT controller, and string configuration.
How to Use This Calculator
Enter your daily energy use (Wh/day), 48V battery bank capacity (Ah), battery type, and peak sun hours. The calculator outputs the complete 48V system specification including panels, battery kWh, days of autonomy, MPPT controller size, inverter size, and string configuration — plus the current comparison to 12V systems.
Why 48V for large systems
48V is the industry standard for large off-grid systems, bus conversions, skoolies, tiny homes, and grid-tie battery systems. At 48V, current is one-quarter of a 12V system for the same power. A 10kW system at 48V draws only 208A — at 12V that would be 833A, requiring extremely heavy cables and creating serious heat and safety concerns. Most professional-grade inverters (Victron Quattro, SMA Sunny Island, Schneider XW+) operate at 48V.
48V battery options
48V batteries can be built from four 12V batteries in series, two 24V batteries in series, or purchased as purpose-built 48V LiFePO4 packs. Server rack LiFePO4 batteries (48V 100Ah = 4.8 kWh) are popular because they're modular, have built-in BMS, and stack neatly in standard server racks.