Battery Capacity Calculator — Formule
## Battery Capacity Sizing
Battery capacity must account for the load, duration, efficiency losses, and depth-of-discharge limits.
### Formula
**Required Ah = (P / V) x Hours / Efficiency / DoD**
where P is load power in watts, V is battery voltage, Hours is the backup duration, Efficiency accounts for inverter and wiring losses, and DoD is the maximum allowable depth of discharge (to protect battery life).
Battery capacity must account for the load, duration, efficiency losses, and depth-of-discharge limits.
### Formula
**Required Ah = (P / V) x Hours / Efficiency / DoD**
where P is load power in watts, V is battery voltage, Hours is the backup duration, Efficiency accounts for inverter and wiring losses, and DoD is the maximum allowable depth of discharge (to protect battery life).
Exemple Résolu
500 W load on a 48V battery system for 4 hours, 80% DoD, 90% efficiency.
- Load current = 500 / 48 = 10.42 A
- Usable capacity = 10.42 x 4 / 0.90 = 46.3 Ah
- Total capacity = 46.3 / 0.80 = 57.9 Ah
- Battery energy = 57.9 x 48 / 1000 = 2.78 kWh