Battery Bank Sizing Calculator
Calculate the exact battery capacity your off-grid system needs. Results in seconds — no signup required.
From your load calculation. A basic cabin is typically 1–3 kWh/day.
How many cloudy days to cover without solar. 2–3 days is standard.
LiFePO4: use 80%. AGM: use 50%. Lead-acid: use 50%.
12V for small systems, 24V for medium, 48V for large.
Your Results
Required Capacity —
100Ah Batteries Needed —
With 25% Safety Buffer —
Buffered Batteries Needed —
Always add a safety buffer. Actual usable capacity varies by temperature and battery age. Consult a licensed electrician for systems over 2kW.
📖 Want to understand the math?
Read our battery guides →