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Battery Bank Sizing Calculator
Battery Bank Sizing Calculator
Enter your daily load and constraints — results update live. Not sure of your daily usage? Use the Solar Calculator first.
Daily Energy Consumption
Daily usage
Wh/day
— or in kilowatt-hours
kWh/day
Battery Chemistry
Days of Autonomy
System Voltage
Temperature Derating
Cold climate adjustment
20% capacity derating applied. At freezing temps, LiFePO4 loses ~15–20% capacity; lead-acid loses 20–30%. A conservative 20% buffer is used for all chemistries.
Core formula:
Total Wh = (Daily Wh × Days of Autonomy) ÷ DoD ÷ Efficiency
Total Ah = Total Wh ÷ System Voltage
Cold climate: Adjusted Ah = Total Ah ÷ 0.80 (25% upsize)
DoD defaults: LiFePO4 = 80%, AGM = 50%, FLA = 50%
Round-trip efficiency: LiFePO4 ≈ 98%, AGM ≈ 85%, FLA ≈ 85%
Sizing Results
Enter your daily usage to see battery bank sizing.